Light-emitting device and lighting apparatus
View Patent ↗A light-emitting device includes: a board; light-emitting elements interconnected in parallel and provided above a top face of the board; light-emitting elements, one of which is connected in series with the light-emitting element and the other of which is connected in series with the light-emitting element, the light-emitting elements being interconnected in parallel; a metal pattern provided continuously under the light-emitting elements, on an undersurface of the board; and a metal pattern provided continuously under the light-emitting elements, and isolated from the first metal pattern.
1. A light-emitting device comprising:
a board;
a plurality of light-emitting elements provided above a top face of the board;
a first metal pattern and a second metal pattern provided on an undersurface of the board; and
a wire pattern provided on the top face of the board, between adjacent light-emitting elements among the plurality of light-emitting elements, the wire pattern connecting the adjacent light-emitting elements,
wherein the plurality of light-emitting elements include:
a first light emitting element and a second light-emitting element interconnected in parallel; and
a third light-emitting element and a fourth light-emitting element, one of which is connected in series with the first light-emitting element and the other of which is connected in series with the second light-emitting element, the third light-emitting element and the fourth light-emitting element being interconnected in parallel and provided above the top face of the board,
the first metal pattern is provided continuously under the first light-emitting element and the second light-emitting element, and
the second metal pattern is provided continuously under the third light-emitting element and the fourth light-emitting element, and isolated from the first metal pattern.
2. The light-emitting device according to claim 1 ,
wherein the third light-emitting element is connected in series with the first light-emitting element and in parallel with the second light-emitting element, and
the fourth light-emitting element is connected in series with the second light-emitting element and in parallel with the first light-emitting element.
3. The light-emitting device according to claim 2 , further comprising:
a fifth light-emitting element provided above the top face of the board, and connected in series with the first light-emitting element and in parallel with the second light-emitting element; and
a sixth light-emitting element provided above the top face of the board, and connected in series with the second light-emitting element and in parallel with the first light-emitting element and the fifth light-emitting element,
wherein the first metal pattern is provided continuously below the first light-emitting element, the second light-emitting element, the fifth light-emitting element, and the sixth light-emitting element.
4. The light-emitting device according to claim 2 , further comprising
a plurality of parallel connection units each including the first light-emitting element and the second light-emitting element,
wherein the parallel connection units are provided between different pairs of terminals, and
the first metal pattern is provided continuously under the parallel connection units.
5. The light-emitting device according to claim 1 ,
wherein a parallel connection unit of the first light-emitting element and the second light-emitting element is connected in series with a parallel connection unit of the third light-emitting element and the fourth light-emitting element.
6. The light-emitting device according to claim 5 , further comprising:
a fifth light-emitting element provided above the top face of the board, and connected in series with the first light-emitting element and in parallel with the second light-emitting element;
a sixth light-emitting element provided above the top face of the board, and connected in series with the second light-emitting element and in parallel with the first light-emitting element and the fifth light-emitting element; and
a third metal pattern provided continuously under the fifth light-emitting element and the sixth light-emitting element, on the undersurface of the board, and isolated from the first metal pattern and the second metal pattern.
7. The light-emitting device according to claim 5 , further comprising:
a fifth light-emitting element and a sixth light-emitting element provided above the top face of the board, and connected in series with the parallel connection unit of the first light-emitting element and the second light-emitting element, the fifth light-emitting element and the sixth light-emitting element being interconnected in parallel; and
a third metal pattern provided continuously under the fifth light-emitting element and the sixth light-emitting element, on the undersurface of the board, and isolated from the first metal pattern and second metal pattern.
8. The light-emitting device according to claim 5 , further comprising
a fifth light-emitting element and a sixth light-emitting element provided above the top face of the board, and connected in series with the parallel connection unit of the first light-emitting element and the second light-emitting element, the fifth light-emitting element and the sixth light-emitting element being interconnected in parallel,
wherein the first metal pattern is provided continuously below the first light-emitting element, the second light-emitting element, the fifth light-emitting element and the sixth light-emitting element.
9. The light-emitting device according to claim 5 , further comprising
a plurality of parallel connection units each including the first light-emitting element and the second light-emitting element,
wherein the parallel connection units are connected in parallel, and
the first metal pattern is provided continuously under the parallel connection units.
10. The light-emitting device according to claim 1 , further comprising terminals and the wiring pattern being among a plurality of wiring patterns, wherein the
wiring patterns and terminals supply electric power to the first light-emitting element, the second light-emitting element, the third light-emitting element and the fourth light-emitting element,
wherein the first metal pattern and the second metal pattern are dielectrically isolated from the wiring patterns.
11. The light-emitting device according to claim 10 ,
wherein a total area of metal patterns on the top face of the board including the wiring patterns and the terminals is substantially equal to a total area of metal patterns on the undersurface of the board including the first metal pattern and the second metal pattern.
12. The light-emitting device according to claim 10 ,
wherein a thickness of metal patterns on the top face of the board including the wiring patterns and the terminals is substantially equal to a thickness of metal patterns on the undersurface of the board including the first metal pattern and the second metal pattern.
13. The light-emitting device according to claim 1 ,
wherein the first metal pattern and the second metal pattern are aligned in a longitudinal direction of the board.
14. The light-emitting device according to claim 1 ,
wherein the board comprises fibers extending in a lateral direction of the board, and wherein the first metal pattern and the second metal pattern are aligned in a direction perpendicular to the lateral direction of the board.
15. A lighting apparatus including the light-emitting device according to claim 1 .
16. A lighting apparatus comprising:
a light-emitting device; and
a base provided with the light-emitting device,
the light-emitting device including:
a board;
a plurality of light-emitting elements provided above a top face of the board;
a first metal pattern and a second metal pattern provided on an undersurface of the board; and
a wire pattern provided on the top face of the board, between adjacent light-emitting elements among the plurality of light-emitting elements, the wire pattern connecting the adjacent light-emitting elements,
wherein the plurality of light-emitting elements include:
a first light emitting element and a second light-emitting element interconnected in parallel;
and
a third light-emitting element and a fourth light-emitting element, one of which is connected in series with the first light-emitting element and the other of which is connected in series with the second light-emitting element, the third light-emitting element and the fourth light-emitting element being interconnected in parallel and provided above the top face of the board,
the base including:
the first metal pattern provided continuously under the first light-emitting element and the second light-emitting element, on a surface with which the undersurface of the board of the light-emitting device is in contact; and
a second metal pattern provided continuously under the third light-emitting element and the fourth light-emitting element, and isolated from the first metal pattern.
17. The light-emitting device according to claim 11 ,
wherein a thickness of metal patterns on the top face of the board including the wiring patterns and the terminals is substantially equal to a thickness of metal patterns on the undersurface of the board including the first metal pattern and the second metal pattern.