[0001] The present disclosure relates to illumination devices, and more particularly to
an illumination device providing efficient heat dissipation.
[0002] A LED lamp includes a heat sink, a printed circuit board and a plurality of LEDs.
The printed circuit board is mounted on a central portion of the heat sink. The LEDs
are mounted on the printed circuit board. Because the heat transfer coefficient of
the printed circuit board is poor it is difficult for the heat sink to dissipate the
heat from the LEDs in a timely manner.
[0003] It is thus desirable to provide an illumination device which can overcome the described
limitations.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] Many aspects of the present disclosure can be better understood with reference to
the following drawings. The components in the drawings are not necessarily drawn to
scale, the emphasis instead placed upon clearly illustrating the principles of the
present disclosure. Moreover, in the drawings, like reference numerals designate corresponding
parts throughout the several views.
[0005] FIG. 1 is a schematic view of an illumination device in accordance with a first embodiment.
[0006] FIG. 2 is a schematic view of an illumination device in accordance with a second
embodiment.
[0007] FIG. 3 is a schematic view of an illumination device in accordance with a third embodiment.
DETAILED DESCRIPTION
[0008] Referring to FIG. 1, an illumination device 100 according to a first embodiment includes
a heat sink 10, a heat transfer member 20, a printed circuit board 30, at least one
solid-state light source 40, a connecting member 50 electrically connecting to a power
source (not shown), and a transparent or translucent envelope 60 which is glass or
plastic.
[0009] The heat sink 10 includes a support portion 11, a connecting portion 13 and a plurality
of fins 12. The fms 12 are radially aligned about an outer circumferential surface
of the heat sink 10 to dissipate the heat therefrom. The support portion 11 of the
heat sink 10 is a flat surface to support the heat transfer member 20 thereon. The
heat sink 10 is made of aluminum or copper.
[0010] The heat transfer member 20 is mounted on the support portion 11 of the heat sink
10. The heat transfer member 20 is made of thermal conductive adhesive.
[0011] The printed circuit board 30 is mounted on the heat transfer member 20. In this embodiment,
a gap is provided between the printed circuit board 30 and the support portion 11
of the heat sink 10.
[0012] The solid-state light source 40 is mounted on the printed circuit board 30. In this
embodiment, the solid-state light source 40 is a LED.
[0013] The connecting member 50 is mounted on the connecting portion 13 of the heat sink
10. The connecting member 50 is electrically connected with the printed circuit board
30 by a wire (not shown). The connecting member 50 is a standard element with a thread
formed thereon, so the illumination device 100 can be directly connected to a standard
socket matching the standard connecting member 50 to electrically connect with the
power source. The illumination device 100 thus can replace an incandescent lamp or
a compact lamp having a connector configuration matching that of the connecting member
50.
[0014] The envelope 60 includes a receiving space 62 and an open end 64. The open end 64
of the envelope 60 is mounted on the support portion 11 of the heat sink 10 and covers
the solid-state light source 40. The envelope 60 is hollow, substantially hemispherical,
and of a light permeable material. The envelope 60 is an optical element, which can
be used to adjust the illumination pattern from the solid-state light source 40.
[0015] The heat transfer member 20 is interposed between the printed circuit board 30 and
the support portion 11 of the heat sink 10, whereby the printed circuit board 30 is
securely and directly mounted on the support portion 11 and thermally connects therewith.
The solid-state light source 40 and the printed circuit board 30 easily dissipate
heat to the heat sink 10 through the heat transfer member 20. Thus, efficiency of
heat dissipation is enhanced and lifespan of the illumination device 100 is increased
in daily use.
[0016] FIG. 2 illustrates an illumination device 100a of a second embodiment of the disclosure,
differing from the first embodiment only in that a plurality of heat transfer members
20a is interposed between the printed circuit board 30a and the support portion 11
of the heat sink 10. A plurality of solid-state light sources 40a is mounted on the
printed circuit board 30a corresponding the heat transfer members 20a. Each electrode
of the solid-state light sources 40a is electrically connected with a circuit on the
printed circuit board 30a.
[0017] FIG. 3 illustrates an illumination device 100b of a third embodiment of the disclosure,
differing from the second embodiment only in that the support portion 11 includes
two angled planes 14 and 16. Each heat transfer members 20b is connected with a corresponding
one of the angled planes 14 and 16 of the heat sink 10. The shape of the printed circuit
board 30b is corresponding to the angled planes 14 and 16 of the heat sink 10. The
printed circuit board 30b is mounted on the heat transfer members 20b. The solid-state
light sources 40b are mounted on the printed circuit board 30b corresponding the heat
transfer members 20b.
[0018] It is to be understood, however, that even though numerous characteristics and advantages
of various embodiments have been set forth in the foregoing description, together
with details of the structures and functions of the embodiments, the disclosure is
illustrative only; and that changes may be made in detail, especially in matters of
arrangement of parts within the principles of the invention to the full extent indicated
by the broad general meaning of the terms in which the appended claims are expressed.
1. An illumination device comprising:
a heat sink comprising a support portion;
at least one heat transfer member mounted on the support portion of the heat sink;
a printed circuit board mounted on the at least one heat transfer member, the printed
circuit board thermally connecting with the heat transfer member;
at least one solid-state light source mounted on the printed circuit board, the at
least one solid-state light source electrically connected with the printed circuit
board.
2. The illumination device of claim 1, wherein the heat sink comprises a plurality of
fins radially aligned about an outer circumferential surface of the heat sink.
3. The illumination device of claim 1, wherein the heat sink is made of aluminum or copper.
4. The illumination device of claim 1, wherein the support portion of the heat sink is
a flat surface.
5. The illumination device of claim 1, wherein the support portion comprises an angled
plane on which the at least one heat transfer member is mounted.
6. The illumination device of claim 1, further comprising a connecting member mounted
on a connecting portion of the heat sink and electrically connected to the printed
circuit board.
7. The illumination device of claim 1, further comprising an envelope comprising a receiving
space and an open end, the open end of the envelope mounted on the support portion
of the heat sink and covering the at least one solid-state light source.
8. The illumination device of claim 7, wherein the envelope is made of a light permeable
material and acts as an optical element for adjusting illumination pattern of the
at least one solid-state light source.
9. The illumination device of claim 1, wherein the at least one heat transfer member
is made of a thermally conductive adhesive.
10. The illumination device of claim 1, wherein a gap is defined between the printed circuit
board and the support portion of the heat sink.
11. The illumination device of claim 1, wherein the at least one solid-state light source
is a LED.