IP Library Granted Patent US 8,399,899
Granted Patent B2
US 8,399,899 · App. 12/827,319 · Granted Mar 19, 2013

Light emitting device

Inventors: Makoto Matsuda (Osaka, JP); Toyonori Uemura (Osaka, JP); Toshio Hata (Osaka, JP)
Assignee: Sharp Kabushiki Kaisha
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Quick Facts
Patent No.
US 8,399,899
App. No.
12/827,319
Granted
Mar 19, 2013
Kind
B2
Abstract

A light emitting device includes: a substrate; an LED chip provided on a main surface of the substrate; and a printed resistor element connected in parallel with the LED chip, the printed resistor element being provided in at least one of regions (i) on the main surface of the substrate, (ii) on a back surface of the substrate, and (iii) inside the substrate. According to the arrangement, it is possible to provide: a light emitting device which can emit light having preferable luminance without a reduction in optical output by suppressing light shielding and light absorption of light emitted from the LED toward the outside; and a method for manufacturing the light emitting device.

Claims (49)

1. A light emitting device comprising:

a substrate;

one or more semiconductor light emitting elements provided on a main surface of the substrate; and

a protective element connected in parallel with each one of the semiconductor light emitting elements,

the protective element being a printed resistor provided in at least one of regions (i) on the main surface of the substrate, (ii) on a back surface of the substrate, and (iii) inside the substrate.

2. The light emitting device as set forth in claim 1 , wherein:

the semiconductor light emitting element is covered with a fluorescent material-containing resin layer or a transmissive resin layer, each provided on the main surface of the substrate, the fluorescent material-containing resin layer being made of a resin containing a fluorescent material, the transmissive resin layer being made of a transmissive resin; and

the protective element is provided on the main surface and outside the fluorescent material-containing resin layer or the transmissive resin layer.

3. The light emitting device as set forth in claim 2 , wherein:

the fluorescent material-containing resin layer or the transmissive resin layer has a dome shape.

4. The light emitting device as set forth in claim 2 , wherein:

the protective element is provided in a corner of the main surface of the substrate.

5. The semiconductor light emitting element as set forth in claim 1 , wherein:

the semiconductor light emitting element is covered with, via a fluorescent material-containing resin layer made of a resin containing a fluorescent material, a transmissive resin layer made of a transmissive resin, the fluorescent material-containing resin layer and the transmissive resin layer being provided on the main surface of the substrate; and

the protective element is provided on the main surface of the substrate and outside the transmissive resin layer.

6. The light emitting device as set forth in claim 5 , wherein:

the transmissive resin layer has a dome shape.

7. The light emitting device as set forth in claim 5 , wherein:

the protective element is provided in a corner of the main surface of the substrate.

8. The light emitting device as set forth in claim 1 , wherein:

the substrate is made of ceramics; and

a wiring pattern is provided on the substrate,

the wiring pattern including: cathode and anode electrodes electrically connected to the semiconductor light emitting element; and cathode and anode electrodes electrically connected to the protective element.

9. The light emitting device as set forth in claim 8 , wherein:

a glass layer is provided on a part of the wiring pattern other than at least the cathode and anode electrodes electrically connected to the semiconductor light emitting element, the wiring pattern being provided on the main surface; and

the protective element is covered with the glass layer, in a case where the protective element is provided on the main surface of the substrate.

10. The light emitting device as set forth in claim 8 , wherein:

the semiconductor light emitting element is provided between the cathode and anode electrodes electrically connected to the semiconductor light emitting element on the main surface of the substrate; and

the protective element is provided on the cathode and anode electrodes electrically connected to the protective element so as to bridge between the cathode and anode electrodes electrically connected to the protective element.

11. The light emitting device as set forth in claim 9 , wherein:

the glass layer is made of at least one selected from the group consisting of a borosilicate glass, a silica glass, a soda-lime glass, an aluminoborosilicate glass, a zinc borosilicate glass, an aluminosilicate glass, and a phosphate glass.

12. The light emitting device as set forth in claim 9 , wherein:

the glass layer has a reflectivity in a range of 70% to 80%.

13. The light emitting device as set forth in claim 11 , wherein:

the glass layer contains at least one selected from the group consisting of: an inorganic dye made from argil, a titanium oxide, a barium oxide, talc, a barium sulfate, an aluminum hydroxide, silica, mica, a calcium carbonate, a calcium sulfate, or clay; and an organic dye made from polymer beads.

14. The light emitting device as set forth in claim 1 , wherein:

the protective element is covered with a glass layer or a solder resist.

15. The light emitting device as set forth in claim 14 , wherein:

either the glass layer or the solder resist is milky white in color.

16. The light emitting device as set forth in claim 1 , wherein:

the protective element has a resistance in a range of 1 MΩ to 10GΩ.

17. The light emitting device as set forth in claim 1 , wherein:

the protective element is partially provided on the main surface of the substrate.

18. The light emitting device as set forth in claim 1 , wherein:

the protective element is provided on the back surface of the substrate.

19. The light emitting device as set forth in claim 1 , wherein:

the semiconductor light emitting element is covered with a fluorescent material-containing resin layer or a transmissive resin layer, each provided on the main surface of the substrate, the fluorescent material-containing resin layer being made of a resin containing a fluorescent material, the transmissive resin layer being made of a transmissive resin;

a white resin ring member is provided around the semiconductor light emitting element so as to dam the fluorescent material-containing resin layer or the transmissive resin layer; and

the protective element is provided on the main surface of the substrate and below the white resin ring member.

Assignments (3)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Mar 4, 2020
From: LEDCOMM LLC
To: HEAVY DUTY LIGHTING LLC
Reel/Frame 052016/0880 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jan 28, 2020
From: SHARP KABUSHIKI KAISHA
To: LEDCOMM LLC
Reel/Frame 051639/0812 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jun 30, 2010
From: MATSUDA, MAKOTO; UEMURA, TOYONORI; HATA, TOSHIO
To: SHARP KABUSHIKI KAISHA
Reel/Frame 024617/0901 →
Priority Claims (1)
JP 2009-157133 · Jul 1, 2009 · national
Continuity (1)
Related Publication 20110001156A1 · Jan 6, 2011