US20070189012A1

US20070189012A1 - Light emitting diode illumination apparatus and heat dissipating method therefor

Info

Publication number: US20070189012A1
Application number: US11/738,522
Authority: US
Inventors: Bin-Juine Huang; Yi-Hai Lian; Fu-Sheng Sun
Original assignee: Advanced Thermal Devices Inc
Current assignee: Advanced Thermal Devices Inc
Priority date: 2003-09-26
Filing date: 2007-04-23
Publication date: 2007-08-16
Also published as: TWI225713B; TW200512953A; US7210832B2; US20050092469A1

Abstract

A light emitting diode (LED) illumination apparatus including an illumination module, a heat dissipating unit and a loop heat pipe (LHP) device is provided. The illumination module includes a base and many LEDs. The LEDs are disposed on the base. The LHP device contains working fluid and includes an evaporator, a condenser, a first transmitting pipe and a second transmitting pipe. The evaporator is associated with the base and has an outlet, an inlet and a chamber. The condenser is conformably associated with the heat dissipating unit. The condenser has an inlet and an outlet, wherein at least one part of the condenser stretches in a curved pipe shape along a surface of the heat dissipating unit. The first transmitting pipe communicates the evaporator outlet to the condenser inlet. The second transmitting pipe communicates the condenser outlet to the evaporator inlet.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of a prior application Ser. No. 10/948,151, filed on Sep. 24, 2004. The prior application Ser. No. 10/948,151 claims the priority benefit of Taiwan application serial no. 92126707, filed on Sep. 26, 2003.

BACKGROUND OF THE INVENTION

1. Field of the Invention
The present invention relates to an illumination apparatus and a heat dissipating method therefor. More particularly, the present invention relates to a light emitting diode (LED) illumination apparatus and a heat dissipating method therefor.
2. Description of Related Art
Light emitting diode (LED) has many advantages, such as small volume, higher illumination efficiency, energy saving and so on. Especially, the photo-electrical power conversion efficiency of the light emitting diode has been rapidly improved during the last twenty years, thus the light emitting diode is regarded as the main illumination source in the future. For energy conservation, the light emitting diode will certainly and gradually being substituted for a lot kinds of today's illumination sources, such as light bulbs.
Today, the light emitting diodes are applied popularly and commonly used in traffic signal lights, electric broads, flash lights, and so on. Although improving the high-power illuminating technology or quality of the light emitting diodes is the future trend and demanded urgently, such as demanded in the application of reading light or protruding light, etc., that still exists some technical bottlenecks to overcome. The main bottleneck for the high-power illuminating technology is the insufficient heat dissipation ability of the traditional illumination apparatus of light emitting diodes often leads to the light emitting diodes in a high operational temperature to decrease theirs service life, further, even to cause them to burn down.
As a high-power or high-brightness LED illumination apparatus concerned, such as above 30˜100 W (watt), it is hard to design an effective heat dissipation means for the LED illumination apparatus without fans. A traditional method of solving the heat dissipation problem is adapting a plurality of cooling fins attached on a base of the illumination apparatus and the heat generated from the light emitting diodes is conducted to the cooling fins via the base, then using an electric fan to blow the heat away, and thereby the heat is dissipated away. As the above-mentioned descriptions, the traditional method of heat dissipation usually requires a large space for setting up the plurality of cooling fins near the illumination apparatus and further needs to install an electric fan, that causes noise and reliability problems when it was used outdoors.
Another method of heat dissipation is adapting a conventional heat pipe device, however, the heat dissipation ability is limited due to the rigidity of the conventional heat pipe device and the limited length of conventional heat pipe device, usually can not be longer than 30 cm. The heat dissipation ability of a conventional heat pipe device is thus mostly less than 30 W. Therefore, the other traditional method also can not solve the heat dissipation problem of the high-power LED illumination apparatus effectively.

SUMMARY OF THE INVENTION

The present invention is directed to a heat dissipating method for an LED illumination apparatus. The heat dissipating method dissipates the heat generated by the LED illumination apparatus away efficiently.
The present invention is further directed to an LED illumination apparatus with better heat dissipating characteristics.
A heat dissipating method for an LED illumination apparatus is provided. The heat dissipating method comprises following steps: using a loop heat pipe (LHP) device to associate an illumination module of the LED illumination apparatus and a heat dissipating unit of the LED illumination apparatus, and transmitting the heat generated from the LEDs to the heat dissipating unit via the LHP device. The LHP device contains working fluid therein and has a condenser and an evaporator. The condenser communicates with the evaporator. The illumination module has a base with a plurality of LEDs thereon. The evaporator is associated with the base. The condenser is comformably associated with the heat dissipating unit. At least one part of the condenser stretches in a curved pipe shape along a surface of the heat dissipating unit in order to utilize said surface of heat dissipating unit for dissipating heat.
According to an embodiment of the present invention, the state of the working fluid in the evaporator may be converted from the liquid state into the vapor state by means of absorbing the heat generated from the LEDs. The working fluid at the vapor state in the evaporator may be transmitted to the condenser. The heat of the vapor in the condenser may be dissipated via the heat dissipating unit to convert the state of the working fluid from the vapor state into the liquid state. The working fluid at the liquid state in the condenser may be then transmitted back to the evaporator. In addition, transmitting the working fluid from the evaporator to the condenser and transmitting the working fluid from the condenser back to the evaporator are accomplished by the capillarity effect of a porous member mounted in the evaporator.
According to an embodiment of the present invention, the heat generated from the LEDs may be conducted to the evaporator via the base. In addition, the base may be also associated with the heat dissipating unit, and the heat generated from the LEDs may be also conducted from the base to the heat dissipating unit directly.
According to an embodiment of the present invention, the heat dissipating method may further comprise using an electric fan disposed beside the condenser and/or the heat dissipating unit to help dissipate the heat away.
According to an embodiment of the present invention, the step of associating the LHP device with the illumination module may comprise adhering at least one part of the condenser to a surface of the heat dissipating unit with an adhesive or welding at least one part of the condenser on a surface of the heat dissipating unit.
According to an embodiment of the present invention, the step of associating the LHP device with the illumination module may comprise using a connector to connect at least one part of the condenser and a surface of the heat dissipating unit. The connector has a recess, and the part of the condenser is pressed into the recess.
An LED illumination apparatus is also provided. The LED illumination apparatus comprises an illumination module, a heat dissipating unit and an LHP device. The illumination module comprises a base and a plurality of LEDs. The LEDs are disposed on the base. The LHP device contains working fluid therein and comprises an evaporator, a condenser, a first transmitting pipe and a second transmitting pipe. The evaporator is associated with the base and has an outlet, an inlet, a chamber and a porous member disposed in the chamber. The chamber may contain the working fluid at the liquid state therein. The condenser is conformably associated with the heat dissipating unit. The condenser has an inlet and an outlet. At least one part of the condenser stretches in a curved pipe shape along a surface of the heat dissipating unit in order to utilize said surface of heat dissipating unit for dissipating heat. One terminal of the first transmitting pipe communicates with the outlet of the evaporator, and the other terminal of the first transmitting pipe communicates with the inlet of the condenser. One terminal of the second transmitting pipe communicates with the outlet of the condenser, and the other terminal of the second transmitting pipe communicates with the inlet of the evaporator.
According to an embodiment of the present invention, the heat dissipating unit may be a housing of the illumination module. In addition, at least parts of the condenser may stretch in a curved pipe shape along the interior surface and/or the exterior surface of the housing. Besides, at least parts of the condenser may stretch in a zigzag shape along the interior surface and/or the exterior surface of the housing.
According to an embodiment of the present invention, the heat dissipating unit may be a cooling plate or a lampshade.
According to an embodiment of the present invention, the base may also be associated with the heat dissipating unit.
According to an embodiment of the present invention, the porous member has a hollow space therein. The working fluid at the liquid state is enveloped in the hollow space by the porous member, and the porous member is suitable for being permeated with the working fluid.
According to an embodiment of the present invention, the working fluid may be selected from a group consisting of water, acetone, ammonia and refrigerant.
According to an embodiment of the present invention, the condenser may comprise at least one capillary pipe.
According to an embodiment of the present invention, the condenser may be integrated with the heat dissipating unit for forming a unity member.
According to an embodiment of the present invention, the base may comprise a circuit board and a conducting unit. The LEDs are disposed on the circuit board. The conducting unit is associated between the circuit board and the evaporator. In addition, the conducting unit may be a flat heat pipe or made of ceramic material, polymeric material or metal.
According to an embodiment of the present invention, the base may have a containing room in which the evaporator is wedged.
According to an embodiment of the present invention, the base may comprise a circuit board, a clamping block and a conducting unit. The LEDs are disposed on said circuit board. The clamping block clamps the evaporator. The conducting unit is associated between the circuit board and the clamping block. In addition, the clamping block has a containing room in which the evaporator is wedged or a recess in which said evaporator is wedged.
According to an embodiment of the present invention, the base is a circuit board, for example.
According to an embodiment of the present invention, at least one part of the condenser may be adhered to a surface of the heat dissipating unit with an adhesive or welded on the surface of the heat dissipating unit.
According to an embodiment of the present invention, the LED illumination apparatus may further comprise at least one connector connected between at least one part of the condenser and a surface of the heat dissipating unit. The connector has a recess, and the part of the condenser is disposed in the recess.
According to an embodiment of the present invention, the LED illumination apparatus may further comprise an electric fan disposed beside the heat dissipating unit and/or the condenser.
According to an embodiment of the present invention, the inside diameters of the condenser, the first transmitting pipe and the second transmitting pipe may be all less than 4 mm, and the total length of the condenser, the first transmitting pipe and the second transmitting pipe may be longer than 600 mm.
According to the present invention, the heat generated from the LEDs can be conducted to the heat dissipating unit via the base and the LHP device. The LHP device has good heat transmitting properties by using the working fluid filled therein to carry the heat generated from the LEDs, such that the LED illumination apparatus in the invention has better heat dissipating characteristics. In addition, by means of using the LHP device to associate the illumination module with the heat dissipating unit of the LED illumination apparatus, the heat dissipating method in the invention dissipates the heat generated from the LEDs efficiently.
The above-mentioned contents of the present invention and the following description of the embodiments are only for example, not intended to limit the scope of the invention. Thus, many equal variations and modifications of the following embodiments could be made without departing form the spirit of the present invention and should be covered by the following claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The objectives, features of the present invention as well as the advantages thereof can be best understood through the following embodiments and the accompanying drawings, wherein:
FIG. 1A is a cross-sectional drawing of an LED illumination apparatus according to an embodiment of the present invention.
FIG. 1B is a three-dimensional schematic drawing of parts of the LED illumination in FIG. 1A.
FIG. 1C is a schematic drawing of the LHP device in FIG. 1A.
FIG. 1D is a schematic drawing of the cross-section A-A of the evaporator shown in FIG. 1C.
FIG. 2A illustrates an LHP device and a clamping block of an LED illumination apparatus according to another embodiment of the present invention.
FIG. 2B is a schematic cross-sectional drawing of the evaporator in FIG. 2A.
FIG. 2C illustrates an LHP device and a clamping block of an LED illumination apparatus according to yet another embodiment of the present invention.
FIG. 3 is the schematic drawing of a LED illumination apparatus according to yet another embodiment of the present invention.
FIG. 4 illustrates a base wedged with an evaporator according to still another embodiment of the present invention.
FIG. 5A is a schematic drawing of an LED illumination apparatus according to yet still another embodiment of the present invention.
FIG. 5B is a three-dimensional schematic drawing of the connector in FIG. 5A.

DESCRIPTION OF THE EMBODIMENTS

The invention will be explained in detail in accordance with the accompanying drawings. It is necessary to illustrate that the drawings in the below could be in simplified forms and not drawn in proportion to the real cases. Further, the dimensions of the drawings are enlarged for explaining and understanding more clearly.
An LHP device has many kinds of characteristics or advantages, for example, the high heat transmitting rate, the far distance heat-transmitting property, the flexibility property, the non-directional property (not influenced by the gravity) and the unidirectional heat-transferring property. Besides, the diameter of the connecting pipe of the LHP device may be less than 4 mm. Therefore, it is very appropriate to use the LHP device to solve the heat dissipation problem for a LED illumination apparatus with high power or high brightness.
In an LED illumination apparatus according to an embodiment of the present invention, an evaporator of the LHP device is associated with the LEDs through a base, and a condenser of the LHP device is associated with a heat dissipating unit. Therefore, the heat generated from the LEDs can be transmitted to the heat dissipating unit via the LHP device, and then dissipated away from the surface of the heat dissipating unit to make the LED illumination apparatus have better heat dissipating characteristics, such that the lifetime of the illumination apparatus of the present invention is increased.
FIG. 1A is a cross-sectional drawing of an LED illumination apparatus according to an embodiment of the present invention. FIG. 1B is a three-dimensional schematic drawing of parts of the LED illumination in FIG. 1A. FIG. 1C is a schematic drawing of the LHP device in FIG. 1A. FIG. 1D is a schematic drawing of the cross-section A-A of the evaporator shown in FIG. 1C. Referring to FIGS. 1A to 1D, the LED illumination apparatus 100 comprises an illumination module 110, a heat dissipating unit 120 and an LHP device 130. The illumination module 110 comprises a base 114 and a plurality of LEDs 112. The LEDs 112 are disposed on the base 114. The LHP device 130 contains working fluid 135 therein. The working fluid 135 may be selected from a group consisting of water, acetone, ammonia and other refrigerants. The LHP device 130 comprises an evaporator 132, a condenser 134, a first transmitting pipe 136 and a second transmitting pipe 138. The evaporator 132 is associated with the base 114 and has an outlet 132 a, an inlet 132 b and a chamber 132 c. The chamber 132 c may contain the working fluid 135′ at the liquid state therein. The condenser 134 is conformably associated with the heat dissipating unit 120. The condenser 134 has an inlet 134 a and an outlet 134 b. At least one part of the condenser 134, as shown in FIG. 1B, stretches in a curved pipe shape along a surface of the heat dissipating unit 120 in order to utilize the surface of heat dissipating unit 120 for dissipating heat. One terminal of the first transmitting pipe 136 communicates with the outlet 132 a of the evaporator 132, and the other terminal of the first transmitting pipe 136 communicates with the inlet 134 a of the condenser 134. One terminal of the second transmitting pipe 138 communicates with the outlet 134 b of the condenser 134, and the other terminal of the second transmitting pipe 138 communicates with the inlet 132 b of the evaporator 132. The heat generated from the LEDs 112 can be transmitted to the heat dissipating unit 120 via the base 114 and the LHP device 130.
In this embodiment, the evaporator 132 may comprise a porous member 132 d in the chamber 132 c. The porous member 132 d has a hollow space 132 e therein. The working fluid 135′ at the liquid state is enveloped in the hollow space 132 e by the porous member 132 d, and the porous member 132 d is suitable for being permeated with the working fluid 135. More specifically, the body of the evaporator 132 may be a hollow metal cylinder shell 102 with a chamber 132 c therein, and a plurality of radial protruding members 104 may extend from the metal cylinder shell 102 to the inner of the metal cylinder shell 102. The porous member 132 d with the hollow space 132 e may be attached within the metal cylinder shell 102 to form a plurality of vapor channels 105 between the metal cylinder shell 102 and the porous member 132 d. The hollow space 132 e may be a hollow cylinder chamber filled with the working fluid 135′ at the liquid state. Due to the capillary effect, the work fluid 135 can permeate through the porous member 132 d into the vapor channels 105.
In this embodiment, the heat dissipating unit 120 may be a housing of the illumination module 110. In addition, at least parts of the condenser 134 may stretch in a curved pipe shape along the interior surface 122 of the heat dissipating unit 120. More specifically, at least parts of the condenser 134 may stretch in a zigzag shape along the interior surface 122 of the heat dissipating unit 120. Because the housing has surfaces with large area, the heat can be dissipated from the housing away quickly.
However, it is not confined in the present invention that the condenser 134 stretches along the interior surface 122 of the heat dissipating unit 120. In other embodiments, the condenser 134 may stretch along the exterior surface of the heat dissipating unit 120 or both the exterior and interior surfaces. Moreover, in other embodiments, the condenser 134 may also pass through the heat dissipating unit 120. Besides, the heat dissipating unit 120 may be a cooling plate, a lampshade disposed around the LEDs 112 to reflect the light emitted from the LED 112 or other objects with large surface and better heat conductivity, wherein at least parts of the condenser 134 may stretch in a curved pipe shape along the exterior surface and/or the interior surface of the lampshade. Moreover, at least parts of the condenser 134 may also stretch in a zigzag shape along the exterior surface and/or the interior surface of the lampshade.
In this embodiment, the condenser 134 may comprise at least one capillary pipe. Besides, at least one part of the condenser 134 may be adhered to the surface of the heat dissipating unit 120 with an adhesive or welded on the surface of the heat dissipating unit 120. In other embodiments, the condenser 134 may also be integrated with the heat dissipating unit for forming a unity member.
In this embodiment, the base 114 may comprise a circuit board 114 a and a conducting unit 114 b. The LEDs 112 are disposed on the circuit board 114 a. The conducting unit 114 b is associated between the circuit board 114 a and the evaporator 132. The conducting unit 114 b may be a flat heat pipe, a metal board or other objects with better heat conductivity for example. The material of conducting unit 114 b may comprise ceramic material, polymeric material or metal. The base 114 may also be associated with the heat dissipating unit 120, such that the heat generated from the LED 112 may also be conducted from the base 114 to the heat dissipating unit 120 directly. However, in other embodiments, the base 114 and the heat dissipating unit 120 may also be disposed separately.
A heat dissipating method according to an embodiment of the present invention is suitable for being applied to the LED illumination apparatus 100 as shown in FIG. 1A. The heat dissipating method comprises the steps of: using the LHP device 130 to associate the illumination module 110 and the heat dissipating unit 120, and transmitting the heat generated from the LEDs 112 to the heat dissipating unit 120 via the LHP device 130.
When the LHP device 130 is transmitting heat, the phenomena occur as mentioned below. In this embodiment, the heat generated from the LEDs 112 may be conducted to the evaporator 132 via the base 114. In addition, the state of the working fluid 135 in the evaporator 132 may be converted from the liquid state into the vapor state by means of absorbing the heat generated from the LEDs 112. More specifically, the heat may be conducted to the metal cylinder shell 102 of the evaporator 132 and then conducted to the porous member 132 d via the radial protruding members 104. Subsequently, the heat is conducted from the porous member 132 to the working fluid 135′ at the liquid state and absorbed thereby. The working fluid 135″ at the vapor state may then permeate through the porous member 132 by the capillarity effect and be transmitted from the evaporator 132 to the condenser 134 by the first transmitting pipe 136. The heat of the working fluid 135″ at the vapor state in the condenser 134 may be dissipated to the environment via the heat dissipating unit 120 to convert the state of the working fluid 135 from the vapor state into the liquid state. The working fluid 135′ at the liquid state in the condenser 134 may be then transmitted back to the evaporator 132 by the second transmitting pipe 138. It should be noted that transmitting the working fluid 135″ at the vapor state from the evaporator 132 to the condenser 134 and transmitting the working fluid 135′ at the liquid state from the condenser 134 back to the evaporator 132 may be accomplished by the capillarity effect of the porous member 132 d mounted in the evaporator 132.
In the LED illumination apparatus 100 and the heat dissipating method according to the above embodiments of the present invention, because the LHP device 130 has good heat transmitting properties as mentioned above to carry the heat generated from the LEDs 112 efficiently, the LED illumination apparatus 100 in the embodiment has higher heat dissipating efficiency, and the heat dissipating method dissipates the heat from the LED illumination apparatus 100 efficiently. Therefore, the lifetime of the LEDs in the LED illumination apparatus 100 is increased. In addition, because of the characteristics and advantages of the LHP device as mentioned above, the LED illumination apparatus 100 also has the advantages that the illumination module 110 can be disposed far away from the heat dissipating unit 120 to improve the design flexibility of the LED illumination apparatus 100, and the LED illumination apparatus 100 can be rotated to any orientation without being affected by the gravity. Besides, an electric fan may not be necessary for the LED illumination apparatus 100 because of the high heat transmitting efficiency of the LHP device 130, such that the size of the LED illumination 100 can be reduced.
In the LED illumination 100 according to this embodiment, an electric fan may be disposed beside the heat dissipating unit 120, such that the heat can be dissipated from the heat dissipating unit 120 more rapidly. In other embodiments, the electric fan may also be disposed beside the condenser 134. In this embodiment, the inside diameters of the condenser 134, the first transmitting pipe 136 and the second transmitting pipe 138 may be all less than 4 mm, and the total length of the condenser 134, the first transmitting pipe 136 and the second transmitting pipe 138 may be longer than 600 mm, demonstrating the high design flexibility for the LHP device 130 in the LED illumination apparatus 100.
FIG. 2A illustrates an LHP device of a LED illumination apparatus according to another embodiment of the present invention, and FIG. 2B is a schematic cross-sectional drawing of the evaporator in FIG. 2A. Referring to FIGS. 2A and 2B, an LHP device 130′ is similar to the LHP device 130 as shown in FIG. 1A, and the difference between the two is mentioned below. Compared with the structure in FIG. 1D, an evaporator 132′ has no radial protruding members 104 as shown in FIG. 1D. Instead, in the evaporator 132′, a porous member 132 d′ is attached to a shell 102′ directly. Besides, the porous member 132 d′ has a plurality of recesses 132 f in its exterior surface to form vapor channels 105. In this embodiment, the heat will be conducted to the shell 102′ of the evaporator 132′ and then conducted to the porous member 132 d′ without passing through the radial protruding members 104 as shown in FIG. 1D. In addition, the evaporator 132′ may be clamped by a clamping block 114 c, and the clamping block is associated with the conducting unit. In this embodiment, the clamping block 114 c may have a containing room 114 c′ in which the evaporator 132′ is wedged. The clamping block 114 c may also be applied in the structure of the LED illumination apparatus 100 as shown in FIG. 1A to associate the conducting unit 114 b with the evaporator 132. Referring to FIG. 2C, in yet another embodiment, a clamping block 114 d may have a recess 114 d′ to replace the containing room 114 c′, and the evaporator 132′ is wedged in the recess 114 d′.
FIG. 3 is the schematic drawing of a LED illumination apparatus according to yet another embodiment of the present invention. Referring to FIG. 3, an LED illumination apparatus 100′ in this embodiment is similar to the LED illumination apparatus 100 as shown in FIG. 1A, and the difference between the two is mentioned below. In this embodiment, a base 114′ is a circuit board associated with the evaporator directly. In other embodiments, the base may be made of metal or other materials with better heat conductivity.
FIG. 4 illustrates a base wedged with an evaporator according to still another embodiment of the present invention. Referring to FIG. 4, a base 114″ in this embodiment is different from the base 114′ as shown in FIG. 3. In this embodiment, the base 114″ may have a containing room 114 c in which the evaporator 132 is wedged. Besides, it is not confined in the present invention that the LED 112 is disposed on only one surface of the base. In this embodiment, the LED 112 may be disposed on multiple surfaces of the base 114″. In other embodiments, a conducting unit may have a containing room or a recess in which the evaporator is wedged.
FIG. 5A is a schematic drawing of a LED illumination apparatus according to another embodiment of the present invention, and FIG. 5B is a three-dimensional schematic drawing of the connector in FIG. 5A. Referring to FIGS. 5A and 5B, an LED illumination apparatus 100″ in this embodiment is similar to the LED illumination apparatus 100 as shown in FIG. 1A, and the difference between the two is mentioned below. In this embodiment, the LED illumination apparatus 100″ further comprises at least one connector 140 connected between at least one part of the condenser 134 and a surface of the heat dissipating unit 120. The connector 140 has a recess 142, and the part of the condenser 134 is disposed in the recess 142. A heat dissipating method according another embodiment of the present invention may also comprise the step of using the connector 140 to connect the part of the condenser 134 and the surface of the heat dissipating unit 120, wherein the condenser 134 is pressed into the recess 140 to fit the shape of the recess 140. Because the connector 140 can contact the condenser 134 and the heat dissipating unit 120 tightly, the heat transmitting efficiency from the condenser 134 to the heat dissipating unit 120 can be improved.
It should be noted that the heat dissipating method according to FIG. 1A can also be applied to the LED illumination apparatuses according to the other embodiments mentioned above.
In view of the foregoing, because the LHP device has high heat transmitting rate, the LED illumination apparatus in the invention has better heat dissipating efficiency, and the heat dissipating method dissipates the heat from the LED illumination apparatus efficiently. Therefore, the lifetime of the LEDs in the LED illumination apparatus is increased. In addition, because of the characteristics and advantages of the LHP device such as the far distance heat-transmitting property, the flexibility property, the non-directional property and the unidirectional heat-transferring property, the LED illumination apparatus in the invention also has the advantages that the illumination module can be disposed far away from the heat dissipating unit to improve the design flexibility of the LED illumination apparatus, and the LED illumination apparatus can be rotated to any orientation without being affected by the gravity. Besides, an electric fan may not be necessary for the LED illumination apparatus because of the high heat transmitting efficiency of the LHP device, such that the size of the LED illumination can be reduced.
It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the present invention cover modifications and variations of this invention provided they fall within the scope of the following claims and their equivalents.

Claims

1. A heat dissipating method for a light emitting diode (LED) illumination apparatus, comprising:

using a loop heat pipe (LHP) device to associate an illumination module of said LED illumination apparatus with a heat dissipating unit of said LED illumination apparatus, wherein said LHP device contains working fluid therein and has a condenser and an evaporator, said condenser communicates with said evaporator, said illumination module has a base with a plurality of LEDs thereon, said evaporator is associated with said base, said condenser is conformably associated with said heat dissipating unit, and at least one part of said condenser stretches in a curved pipe shape along a surface of said heat dissipating unit in order to utilize said surface of heat dissipating unit for dissipating heat; and

transmitting the heat generated from said LEDs to said heat dissipating unit via said LHP device.

2. The heat dissipating method according to claim 1, wherein the state of said working fluid in said evaporator is converted from the liquid state into the vapor state by means of absorbing said heat generated from said LEDs, said working fluid at the vapor state in said evaporator is transmitted to said condenser, the heat of said working fluid at the vapor state in said condenser is dissipated via said heat dissipating unit to convert the state of said working fluid from the vapor state into the liquid state, and said working fluid at the liquid state in said condenser is then transmitted back to said evaporator.

3. The heat dissipating method according to claim 2, wherein transmitting said working fluid from said evaporator to said condenser and transmitting said working fluid from said condenser back to said evaporator are accomplished by the capillarity effect of a porous member mounted in said evaporator.

4. The heat dissipating method according to claim 1, wherein said heat generated from said LEDs is conducted to said evaporator via said base.

5. The heat dissipating method according to claim 4, wherein said base is also associated with said heat dissipating unit, and said heat generated from said LEDs is also conducted from said base to said heat dissipating unit directly.

6. The heat dissipating method according to claim 1, further comprising using an electric fan disposed beside said condenser and/or said heat dissipating unit to help dissipate said heat away.

7. The heat dissipating method according to claim 1, wherein the step of associating said LHP device with said illumination module comprises adhering at least one part of said condenser to a surface of said heat dissipating unit with an adhesive or welding at least one part of said condenser on a surface of said heat dissipating unit.

8. The heat dissipating method according to claim 1, wherein the step of associating said LHP device with said illumination module comprises using a connector to connect at least one part of said condenser and a surface of said heat dissipating unit, said connector has a recess, and said part of said condenser is pressed into said recess.

9. An LED illumination apparatus, comprising:

an illumination module, comprising:

a base; and

a plurality of LEDs, disposed on said base;

a heat dissipating unit; and

an LHP device, containing working fluid therein, said LHP device comprising:

an evaporator, associated with said base, said evaporator having an outlet, an inlet, a chamber and a porous member disposed in said chamber;

a condenser, conformably associated with said heat dissipating unit, said condenser having an inlet and an outlet, wherein at least one part of said condenser stretches in a curved pipe shape along a surface of said heat dissipating unit in order to utilize said surface of heat dissipating unit for dissipating heat;

a first transmitting pipe, wherein one terminal of said first transmitting pipe communicates with said outlet of said evaporator, and the other terminal of said first transmitting pipe communicates with said inlet of said condenser; and

a second transmitting pipe, wherein one terminal of said second transmitting pipe communicates with said outlet of said condenser, and the other terminal of said second transmitting pipe communicates with said inlet of said evaporator.

10. The LED illumination apparatus according to claim 9, wherein said heat dissipating unit is a housing of said illumination module.

11. The LED illumination apparatus according to claim 10, wherein at least parts of said condenser stretch in a curved pipe shape along the interior surface and/or the exterior surface of said housing.

12. The LED illumination apparatus according to claim 11, wherein at least parts of said condenser stretch in a zigzag shape along said interior surface and/or said exterior surface of said housing.

13. The LED illumination apparatus according to claim 9, wherein said heat dissipating unit is a cooling plate or a lampshade.

14. The LED illumination apparatus according to claim 9, wherein said base is also associated with said heat dissipating unit.

15. The LED illumination apparatus according to claim 9, wherein said porous member has a hollow space therein, said working fluid at the liquid state is enveloped in said hollow space by said porous member, and said porous member is suitable for being permeated with said working fluid.

16. The LED illumination apparatus according to claim 9, wherein said working fluid is selected from a group consisting of water, acetone, ammonia and refrigerant.

17. The LED illumination apparatus according to claim 9, wherein said condenser comprises at least one capillary pipe.

18. The LED illumination apparatus according to claim 9, wherein said condenser is integrated with said heat dissipating unit for forming a unity member.

19. The LED illumination apparatus according to claim 9, wherein said base comprises:

a circuit board, wherein said LEDs are disposed on said circuit board; and

a conducting unit, associated between said circuit board and said evaporator.

20. The LED illumination apparatus according to claim 19, wherein said conducting unit is a flat heat pipe or made of ceramic material, polymeric material or metal.

21. The LED illumination apparatus according to claim 9, wherein said base has a containing room in which said evaporator is wedged.

22. The LED illumination apparatus according to claim 9, wherein said base comprises:

a circuit board, wherein said LEDs are disposed on said circuit board;

a clamping block, clamping said evaporator; and

a conducting unit, associated between said circuit board and said clamping block.

23. The LED illumination apparatus according to claim 22, wherein said clamping block has a containing room in which said evaporator is wedged or a recess in which said evaporator is wedged.

24. The LED illumination apparatus according to claim 9, wherein said base is a circuit board.

25. The LED illumination apparatus according to claim 9, wherein at least one part of said condenser is adhered to a surface of said heat dissipating unit with an adhesive or welded on the surface of said heat dissipating unit.

26. The LED illumination apparatus according to claim 9, further comprising at least one connector connected between at least one part of said condenser and a surface of said heat dissipating unit, wherein said connector has a recess, and said part of said condenser is disposed in said recess.

27. The LED illumination apparatus according to claim 9, further comprising an electric fan disposed beside said heat dissipating unit and/or said condenser.

28. The LED illumination apparatus according to claim 9, wherein the inside diameters of said condenser, said first transmitting pipe and said second transmitting pipe are all less than 4 mm, and the total length of said condenser, said first transmitting pipe and said second transmitting pipe is longer than 600 mm.