U.S. patent application number 13/366706 was filed with the patent office on 2013-04-18 for heat dissipating structure for light bulb.
The applicant listed for this patent is I-Ming CHEN. Invention is credited to I-Ming CHEN.
Application Number | 20130092362 13/366706 |
Document ID | / |
Family ID | 46460460 |
Filed Date | 2013-04-18 |
United States Patent
Application |
20130092362 |
Kind Code |
A1 |
CHEN; I-Ming |
April 18, 2013 |
HEAT DISSIPATING STRUCTURE FOR LIGHT BULB
Abstract
The present invention provides a heat dissipating structure for
a light bulb and enhances the heat dissipating efficiency of the
light bulb. The heat dissipating structure comprises a heat
dissipating housing and a plurality of fins. The light source is
assembled on the plurality of fins. The heat generated by the light
source is conducted to the heat dissipating housing via the
plurality of fins. In addition, a power driver is disposed at the
bottom of the plurality of fins and dissipates heat through the
heat dissipating housing. Thereby, the light source and the power
driver, which are two heat sources, are disposed separately. Then
the heat is transferred to the surrounding environment by means of
the heat dissipating housing. Consequently, the overall heat
dissipating process is accelerated, thus improving the light
emitting efficiency and lifetime of the light bulb.
Inventors: |
CHEN; I-Ming; (US) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
CHEN; I-Ming |
|
|
US |
|
|
Family ID: |
46460460 |
Appl. No.: |
13/366706 |
Filed: |
February 6, 2012 |
Current U.S.
Class: |
165/185 |
Current CPC
Class: |
F21K 9/23 20160801; F21Y
2115/10 20160801; F21K 9/232 20160801; F21V 29/83 20150115 |
Class at
Publication: |
165/185 |
International
Class: |
F28F 7/00 20060101
F28F007/00 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 13, 2011 |
TW |
100219135 |
Claims
1. A heat dissipating structure for a light bulb, comprising: a
heat dissipating housing; and a plurality of fins, disposed
surrounding the inner walls of said heat dissipating housing.
2. The heat dissipating structure for a light bulb of claim 1, and
further comprising a substrate, screwed on said plurality of
fins.
3. The heat dissipating structure for a light bulb of claim 1,
wherein said plurality of fins further comprise a annular member
disposed at the center of said heat dissipating housing and
connecting with said plurality of fins.
4. The heat dissipating structure for a light bulb of claim 3,
wherein said annular member is hollow.
5. The heat dissipating structure for a light bulb of claim 3,
wherein said annular member connects with said plurality of fins
and some of said plurality of fins extend to the central part of
said annular member.
6. The heat dissipating structure for a light bulb of claim 3,
wherein the center of said annular member is a solid member.
7. The heat dissipating structure for a light bulb of claim 1,
wherein a plurality of first heat dissipating holes are disposed on
said heat dissipating housing.
8. The heat dissipating structure for a light bulb of claim 7,
wherein the diameters of said plurality of first heat dissipating
holes increase progressively from the bottom of said heat
dissipating housing.
9. The heat dissipating structure for a light bulb of claim 1,
wherein a plurality of screw holes are disposed on said plurality
of fins.
10. The heat dissipating structure for a light bulb of claim 1,
wherein not all of the lengths of said plurality of fins are
identical.
11. The heat dissipating structure for a light bulb of claim 1,
wherein said heat dissipating housing and said plurality of fins
are formed integrally.
12. The heat dissipating structure for a light bulb of claim 1,
wherein an accommodating part is disposed at the bottom of said
plurality of fins.
13. The heat dissipating structure for a light bulb of claim 12,
wherein a power connecting part is disposed in said accommodating
part and said power connecting part is a hollow member.
14. The heat dissipating structure for a light bulb of claim 13,
wherein a power driver is disposed in said power connecting
part.
15. The heat dissipating structure for a light bulb of claim 13,
wherein a plurality of second heat dissipating holes are disposed
on said power connecting part.
16. The heat dissipating structure for a light bulb of claim 15,
wherein a plurality of first heat dissipating holes are disposed on
said heat dissipating housing and opposed to said plurality of
second heat dissipating holes.
17. The heat dissipating structure for a light bulb of claim 13,
wherein a plurality of vertical heat dissipating holes are disposed
at the bottom and top of said hollow member.
18. The heat dissipating structure for a light bulb of claim 17,
wherein a plurality of second heat dissipating holes are disposed
on said power connecting part, and said plurality of vertical heat
dissipating holes are disposed opposed to said plurality of second
heat dissipating holes.
Description
FIELD OF THE INVENTION
[0001] The present invention relates generally to a heat
dissipating structure for a light bulb, and particularly to a heat
dissipating structure for a light bulb capable of enhancing the
heat dissipating efficiency.
BACKGROUND OF THE INVENTION
[0002] Modern tungsten filament incandescent lamps are invented
around at the turn of 20th century. The light-emitting member
therein is a filament made of tungsten, which is characterized in
high melting point and hence maintaining its solid state at high
temperatures. Consequently, the light bulb can have a certain
lifetime; the filament will not burn broken within a short time. In
practice, the temperature of the filament in a lighted incandescent
lamp is as high as 3000.degree. C. It is the light radiation
generated by the heated filament that the lamp could emit light.
Thereafter, nights will no longer be barriers for people's lives.
With the shiny light of incandescent lamps, various night
activities, including works or living, can go on with convenience
and thus creating more possibilities. Thereby, the invention of
incandescent lamps alters the lifestyle of people significantly and
extends the active time sections into more directions, hence
enabling possibilities in varied developments.
[0003] With the progress of lighting technologies, a variety of
lighting lamps are developed. Among all of electrical lighting
lamps, incandescent lamps are least efficient. Only 12-18% of the
consumed electrical energy is converted into light, meaning a very
bad energy conversion. The rest energy is dissipated in the form of
heat, which means most energy is wasted. Following the daily
advancement of technologies, the light-emitting diodes (LEDs)
technology as well as the associated integrated-circuit control
devices and heat dissipating technology are getting mature,
enabling diversified applications such as low-power power
indicators, light sources for keypads of mobile phones, LED
backlight modules, and general lighting products. They are
gradually replacing the traditional light-emitting sources. As
opposed to the short lifetime and generated heat of incandescent
lamps, LEDs own the advantages of low power consumption, no
mercury, no halides, and low carbon dioxide emissions. In
considering the environmental protection issue including saving
energy, reducing carbon emissions, and reducing mercury and halide
usage, many countries have set a deadline for starting prohibition
against usage of incandescent lamps. Meanwhile, LEDs will be
promoted completely.
[0004] Because LEDs feature point-source lighting behavior, they
are more flexible in design. They can make up lighting lamps having
distributed light sources and hence not offending to the eye; they
can constitute lighting lamps focusing at a point or over a
specific zone; they also can generate vivid and bright colors. The
light emitting efficiency of white LEDs has been over 701 m/W,
exceeding 151 m/W of incandescent lamps. Currently, only 35% of the
input power to LEDs is converted into light. The rest 65% is
converted into heat, which is the main cause of low light emitting
efficiency for LEDs. In addition, if the heat dissipating mechanism
of the whole device is bad, the generated head by LEDs will
accumulate therein and hence shortening the lifetime of LEDs. In
general, the lifetime of a LED lamp is above 100,000 hours.
Nonetheless, if the operating temperature is above 85.degree. C.,
its lifetime will be greatly reduced.
[0005] Accordingly, when light bulbs, including LED bulbs, are
being used, heat generation is an inevitable result. Heat
dissipation is the method for solving this problem. The emphasis of
related technologies will be put on how to improve the heat
dissipating efficiency of each component and thus increasing the
lifetime. In addition to the light source, in a light lamp, there
is still a power driver, which will generate heat, too. If heat
dissipation of the power driver is inferior, the efficiency of LED
lamp will still be bad. Even worse, the LED lamp possibly cannot be
turned on. Thereby, if both of these two parts have bad heat
dissipation or even influence each other, the temperature will goes
up tremendously. In addition to reducing the lifetime of the LED
lamp, the room temperature might possibly be raised and leading to
discomfort of users. Accordingly, the mechanism of heat dissipation
is a very important subject in this field.
[0006] Almost all of the heat dissipating structures of current
bulbs in the market are of outer fin type. The outer fins of the
structure extend from the center of the bulk. A space is left at
the center for accommodating the power driver, which itself is a
heat generating member. When the heat generated by the light source
is conducted to the outer fins by thermal conduction, heat will
completely surround the power driver. Then, the heat will be added
to heat generated by the power driver and producing the co-heating
effect. Owing to this effect, the internal temperature will be
exceedingly high, resulting in damages on the electronic
components, such as electrolyte capacitors, which have maximum
operating temperature of 105.degree. C. and lifetime of 8,000
hours, in the power driver. In addition to severely affecting the
lifetime of the power driver, the light emitting efficiency is
lowered because the temperature of the light source cannot be
reduced due to the co-heating effect. Instead of the light emitting
efficiency of the light source itself, the lowering in light
emitting efficiency is frequently caused by damages in the power
driver.
[0007] According to the outer-fin typed heat dissipating structure,
only heat generated by the light source can be dissipated by an
imperfect heat dissipating mechanism. For the power driver placed
therein, no mechanism exists for dissipating the heat generated
thereby. Besides, the heat generated by the power driver and by the
light source will induce the co-heating effect, which will result
in damages of the electronic components in the power driver and
thus affecting the lifetime of the light bulb. The present
invention provides a heat dissipating structure for a light bulb,
which is mainly used in heat dissipation of the light bulb. The
heat dissipating structure according to the present invention
improves the drawbacks of the outer-fin typed heat dissipating
structure as well as providing a heat dissipating method for the
power driver in order to solve the co-heating effect effectively.
Thereby, in addition to enhancing the lifetime of the light bulb,
thanks to the improvement in heat dissipation, the light emitting
efficiency of the light source can be raised as well. For users, it
is safer. The subsequent problems caused by damages of the light
bulb because of high temperature can be eliminated.
SUMMARY
[0008] An objective of the present invention is to provide a heat
dissipating structure for a light bulb, which uses a heat
dissipating housing. A plurality of fins are disposed inside and
surrounding the heat dissipating housing, so that the contact area
between the heat dissipating housing and air can be increased.
Thereby, heat energy can be transferred to the surrounding
environment rapidly. The heat dissipating process is accelerated.
The overall heat dissipating mechanism and performance are
enhanced. Accordingly, the lifetime of the light bulb is
improved.
[0009] Another objective of the present invention is to provide a
heat dissipating structure for a light bulb, which uses a power
connecting part. A power driver is disposed in the power connecting
part. The power connecting part is disposed at the bottom of the
plurality of fins. The heat dissipating housing and the power
connecting part are separated effectively and maintaining a
spacing. Thereby, the heat generated by the power driver in the
power connecting part can be dissipated through heat dissipating
holes on the heat dissipating housing.
[0010] For achieving the objectives described above, the present
invention provides a heat dissipating structure for a light bulb
comprising a heat dissipating housing and a plurality of fins. The
plurality of fins are disposed surrounding the inner walls of the
heat dissipating housing. The light source is disposed on the
plurality of fins. When the light source generates heat, the heat
is conducted to the heat dissipating housing via the fins
contacting directly with the light source and dissipated through
the heat dissipating housing. By means of the structure, the heat
dissipating process can be accelerated. Heat will not be
accumulated in the light source. Thereby, the light emitting
efficiency and lifetime of the light source can be improved
substantially.
[0011] In addition, the present invention further comprises a power
connecting part. A power driver is disposed in the power connecting
part. The power connecting part is disposed at the bottom of the
plurality of fins for separating the light source and from the
power connecting part. The heat dissipating housing can dissipate
effectively the heat generated by the power driver. Thereby, the
lifetime of the power driver, and hence that of the light bulb, are
improved.
[0012] Moreover, the heat dissipating housing of the heat
dissipating structure further comprises a plurality of heat
dissipating holes disposed on the surfaces of the heat dissipating
housing and the power connecting part. Thereby, the heat
dissipating efficiency can be raised.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1A shows a top view of the heat dissipating structure
according to a preferred embodiment of the present invention;
[0014] FIG. 1B shows a side view of the heat dissipating structure
according to a preferred embodiment of the present invention;
[0015] FIG. 1C shows a bottom view of the heat dissipating
structure according to a preferred embodiment of the present
invention;
[0016] FIG. 1D shows a three-dimensional view of the heat
dissipating structure according to a preferred embodiment of the
present invention;
[0017] FIG. 2A shows a top view of the heat dissipating structure
according to another preferred embodiment of the present
invention;
[0018] FIG. 2B shows a side view of the heat dissipating structure
according to another preferred embodiment of the present
invention;
[0019] FIG. 2C shows a bottom view of the heat dissipating
structure according to another preferred embodiment of the present
invention;
[0020] FIG. 2D shows a three-dimensional view of the heat
dissipating structure according to another preferred embodiment of
the present invention;
[0021] FIG. 3 shows a schematic diagram of the assembly of the
light source and the heat dissipating structure according to
another preferred embodiment of the present invention;
[0022] FIG. 4 shows a schematic diagram of the light source and the
heat dissipating structure after assembly according to another
preferred embodiment of the present invention; and
[0023] FIG. 5 shows a three-dimensional view of the heat
dissipating structure adopting a solid member according to another
preferred embodiment of the present invention.
DETAILED DESCRIPTION
[0024] In order to make the structure and characteristics as well
as the effectiveness of the present invention to be further
understood and recognized, the detailed description of the present
invention is provided as follows along with embodiments and
accompanying figures.
[0025] The present invention relates to a heat dissipating
structure for a light bulb, which is provided for solving the
problems encountered by the outer-fin type dissipating structure.
The drawbacks include difficult heat dissipation of the light
source and the co-heating effect of the light source and the power
driver. According to the heat dissipating structure of the present
invention, the light emitting efficiency and lifetime of light
bulbs can be improved.
[0026] FIGS. 1A, 1B, 1C, and 1D show top, side, bottom, and
three-dimensional views of the heat dissipating structure according
to a preferred embodiment of the present invention. A heat
dissipating structure 10 according to the present invention
comprises a heat dissipating housing 11 and a plurality of fins 12.
The plurality of fins 12 surrounds the inner walls of the heat
dissipating housing 11. The heat generated by the light source is
transferred to the heat dissipating housing 11 via the plurality of
fins and hence dissipating the heat. The lengths of the plurality
of fins 12 can be different or identical. According to prior art,
heat is dissipated via a cup-shaped member. The function and
structure of the cup-shaped member is similar to the heat
dissipating housing according to the present invention. A great
deal of the generated heat is absorbed first by the thin cup-shaped
member and then dissipated via fins. Because the absorption
enthalpy of the thin cup-shaped member is quite limited, the
overall heat cannot be dissipated efficiently by first absorbed by
the cup-shaped member and then transferred to the fins for heat
dissipation. On the contrary, according to the present invention,
heat is first absorbed by the plurality of fins 12 and then
dissipated by means of the heat dissipating housing 11. Because the
total absorption enthalpy of the plurality of fins 12 is greater
than that of the heat dissipating housing 11, the present invention
has better heat dissipating efficiency.
[0027] Besides, the heat dissipating housing 11 of the heat
dissipating structure further comprises a plurality of first heat
dissipating holes 111 disposed on the surface of the heat
dissipating housing 11. After the plurality of fins 12 absorb heat,
the heat is transferred to the heat dissipating housing 11 for
dissipation. In addition, the plurality of heat dissipating holes
11 are used for heat convection. Air enters to the end having lower
temperature and heat is exhausted from the end having higher
temperature. Thereby, the heat absorbed by the plurality of fins 12
is exhausted efficiently. According to the present invention, heat
exchanged is performed between the surfaces of the plurality of
fins 12 and of the heat dissipating housing 11 and external air.
Moreover, the plurality of first heat dissipating holes 11 can
reinforce heat convection and thus enhancing cooling effect. The
diameters of the plurality of first heat dissipating holes 111
increase progressively from the bottom having a narrower opening to
the top having a wider opening. The arrangement of the diameters of
the plurality of first heat dissipating holes 111 is not limited
the progressive increase fashion as described above. Other
variations in diameters are possible and can be adjusted flexibly
according to the practical requirements. Thereby, the heat
dissipating efficiency is further improved.
[0028] In addition, the present invention further comprises an
accommodating part 13 disposed at the bottom of the plurality of
fins 12 and inside the heat dissipating housing 11. The function of
the accommodating part 13 will be described later.
[0029] FIGS. 2A, 2B, 2C, and 2D show top, side, bottom, and
three-dimensional views of the heat dissipating structure according
to another preferred embodiment of the present invention. The fins
of a heat dissipating structure 20 according to the present
invention have a different shape as shown in the figures. The heat
dissipating structure 20 comprises a heat dissipating housing 21
and a plurality of fins 22. The plurality of fins 22 surrounds the
inner walls of the heat dissipating housing 21. The plurality of
fins 22 further comprises an annular member 222, which is hollow.
Some of the plurality of fins 22 extends to the central part of the
annular member 222. The plurality of fins 22 and the annular member
222 can be an integral structure. Thereby, the heat generated by
the light source is transferred efficiently to the heat dissipating
housing 21.
[0030] Moreover, the present invention further comprises an
accommodating part 23 disposed at the bottom of the plurality of
fins 22 and inside the heat dissipating housing 21. The function of
the accommodating part 23 will be described later.
[0031] FIG. 3 shows a schematic diagram of the assembly of the
light source and the heat dissipating structure according to
another preferred embodiment of the present invention; FIG. 4 shows
a schematic diagram of the light source and the heat dissipating
structure after assembly according to another preferred embodiment
of the present invention. The light bulb according to the present
invention comprises a light source 30, which includes a substrate
32. The substrate 32 contacts the top of the plurality of fins 12;
the sides of the substrate 32 touches closely the upper end of the
inner walls of the heat dissipating housing 11, wherein thermally
conductive paste can be used for tightly adhering both to each
other. The present invention further comprises a power connecting
part 34 disposed in the accommodating part 13. The power connecting
part 34 is hollow and has a power driver 342 disposed therein. When
the power driver 342 is disposed inside the power connecting part
34, thermally conductive paste can be applied too for transferring
the heat generated by the power driver 342 to the power connecting
part 34 rapidly. A plurality of LED chips are disposed on the
substrate 32. For a better heat dissipating effect, thermally
conductive paste or heat sinks can be used on the contact surface
between the substrate 32 and the plurality of fins 12 for touching
each other closely. Be means of heat conduction, heat can be
transferred rapidly from the substrate 32 to the plurality of fins
12 and to the heat dissipating housing 11.
[0032] The light source 30 further includes a lampshade 31 disposed
above the substrate 32. The material of the lampshade 31 includes
transparent or light dispersive materials. The light source 30
adopts LED modules and LEDs are point light sources. For avoiding
visual discomfort caused by the glare, the lampshade 31 adopts the
acrylic materials having light dispersion particles for dispersing
the light of LEDs.
[0033] Furthermore, the heat dissipating housing 11 of the heat
dissipating structure 10 has the plurality of first heat
dissipating holes 111. Because the plurality of first heat
dissipating holes 111 are dispose on the surface of the heat
dissipating housing 11, the heat dissipating efficiency of the heat
dissipating housing is improved. The plurality of fins 12 of the
heat dissipating structure 10 further include a plurality of screw
holes 121. A plurality of screws 321 are screwed into the plurality
of screw holes 121 on the plurality of fins 12 for fixing the
substrate 32. The material of the plurality of screws 321 can be
material having high thermal conductivity, for example, copper,
gold, aluminum, and other metals or ceramic materials having good
heat dissipating capability.
[0034] Because the substrate 32 is the heat source, its heat
dissipating mechanism varies according to various parts thereof
First, at the bottom of the substrate 32, the generated heat is
guided to the heat dissipating housing 11 via the plurality of fins
12 for heat dissipation. Next, the heat generated at the sides of
the substrate 32 can be transferred outwards thanks to their direct
contact with the heat dissipating housing 11 and then convected
with external air and thus achieving heat dissipation. Finally,
heat dissipation at the top of the substrate is accomplished by
guiding the heat directly to the plurality of fins 12 by means of
the plurality of screws 321 and then transferring the heat to the
bottom of the heat dissipating housing for rapid heat dissipation.
Thereby, the heat dissipating mechanism according to the present
invention features multiple heat guiding channels for bringing the
heat of the substrate 32 away rapidly.
[0035] In addition, the power connecting part 34 in the light
source 30 further includes a plurality of second heat dissipating
holes 341. A lid 33, which isolates the heat generated by the
substrate 32 from the power connecting part 34, is disposed above
the power connecting part 34. Without such isolation, the
electronic components of the power driver 342 inside the power
connecting part 34 will be damaged owing to the co-heating effect
caused by the heat transferred from the substrate 33. Besides,
there is no heat dissipating method for the power driver 342 in
prior art. Hence, the heat of the power driver 342 in the light
bulb cannot be dissipated. If the substrate 32 is not isolated from
the power driver 342, the heat of the substrate 32 and that of the
power driver 342 induce the co-heating effect. The generated high
temperature affects the lifetime and light emitting efficiency of
the light bulb. The lifetime of the LED chips as well as that of
the power driver are also affected. Thereby, the plurality of
second heat dissipating holes 341 and a plurality of vertical heat
dissipating holes 343 are disposed on the side and vertical
surfaces of the power connecting part 34. The disposal of the
plurality of heat dissipating holes 341, 343 matches the first heat
dissipating holes 111 on the heat dissipating housing 11, avoiding
them from being blocked by the plurality of fins 12. Consequently,
the convecting air can flow outwards directly, and thus improving
the heat dissipating efficiency of the power driver 342. According
to the present embodiment, when the light bulb is used
horizontally, cold air enters from the bottom via the plurality of
second heat dissipating holes 341 and hot air exhausts to the top
by convection for expelling the heat generated by the power driver
342. On the other hand, when the light bulb is used vertically, air
is exchanged through the plurality of vertical heat dissipating
holes 343. Thereby, no matter what direction the light bulb is
used, the heat generated by the power driver 342 can be exhausted
by thermal convection. Accordingly, when the heat dissipating
structure according to the present invention is applied to a light
bulb, its application will not be limited to a single direction,
and hence bringing more convenience in usage.
[0036] FIG. 5 shows a three-dimensional view of the heat
dissipating structure adopting a solid member according to another
preferred embodiment of the present invention. As shown in the
figure, the center of the annular member 222, which is disposed in
the heat dissipating structure 20 and connecting with the plurality
of fins 22, can be solid member 223. Alternatively, a plurality of
the annular members 222 connecting with the plurality of fins 22
can be adopted. The number can be adjusted according to the
requirement. The shape or number is not limited to the above
description.
[0037] To sum up, the present invention provides a heat dissipating
structure for a light bulb and enhances the heat dissipating
efficiency of the light bulb. The heat dissipating structure
comprises a heat dissipating housing and a plurality of fins. The
light source is assembled on the plurality of fins. The heat
generated by the light source is conducted to the heat dissipating
housing via the plurality of fins. In addition, a power driver is
disposed at the bottom of the plurality of fins and dissipates heat
through the heat dissipating housing. Thereby, the light source and
the power driver, which are two heat sources, are disposed
separately. Then the heat is transferred to the surrounding
environment by means of the heat dissipating housing. Consequently,
the overall heat dissipating process is accelerated, thus improving
the light emitting efficiency and lifetime of the light bulb and
advantaging industrial and domestic applications.
[0038] Accordingly, the present invention conforms to the legal
requirements owing to its novelty, nonobviousness, and utility.
However, the foregoing description is only embodiments of the
present invention, not used to limit the scope and range of the
present invention. Those equivalent changes or modifications made
according to the shape, structure, feature, or spirit described in
the claims of the present invention are included in the appended
claims of the present invention.
* * * * *