EP2781831A1

EP2781831A1 - Led lighting device

Info

Publication number: EP2781831A1
Application number: EP12850634.2A
Authority: EP
Inventors: Sang Cheol Lee
Original assignee: Icepipe Corp
Current assignee: Icepipe Corp
Priority date: 2011-11-14
Filing date: 2012-11-07
Publication date: 2014-09-24
Also published as: KR101318432B1; MX2014005825A; AU2012337592A1; WO2013073792A1; EP2781831A4; CA2852827A1; KR20130054096A

Abstract

An LED lighting apparatus is disclosed. The LED lighting apparatus in accordance with an aspect of the present invention includes: a first cover having ventilation holes formed therein; a thermal base having an opening formed on one side thereof and being coupled with the first cover on the other side thereof and having an airflow path for connecting the ventilation holes with the opening formed on an inside thereof and configured to guide flow of air being flowed into the airflow path; LED packages disposed on an outside of the thermal base and configured to dissipate heat by the air flowing through the airflow path; an electric connector being coupled to the first cover and electrically connected with the LED packages; and a second cover covering the LED packages, and the thermal base has a reflective surface formed thereon for reflecting and diffusing at least some of light generated by the LED packages.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Korean Patent Application Nos. 10-2011-0118364 and 10-2012-0002034 , filed with the Korean Intellectual Property Office on November 14, 2011 and January 6, 2012, respectively, the disclosure of which is incorporated herein by reference in their entirety.

BACKGROUND

1. Technical Field

The present invention relates to an LED lighting apparatus.

2. Background Art

An LED lighting apparatus has a large amount of heat generated due to heat generated by LED. Generally, when the LED lighting apparatus is overheated, the LED lighting apparatus may malfunction or be damaged, and thus it is essentially required to equip the LED lighting apparatus with a heat-dissipating structure in order to prevent the overheating. Moreover, a power supply apparatus for supplying electric power to LED also generates a large amount of heat and suffers with shortened life.
To prevent the overheating problem, Korean Patent Publication 2009-0095903 has disclosed a structure in which a heat sink is installed on an entire external circumferential surface of the body to which a light source is coupled. In other words, in the disclosed structure, the entire surface, except the portion in which LED packages are installed, is used for dissipation of the heat generated by the LED.
As the LED-generated light is very dense and straight, generating the light in a narrow area only will illuminate a specific area too intensely, causing a severe glare. Particularly, the conventional LED lighting apparatus uses most of the surface area for heat-dissipation in order to secure a sufficient heat-dissipating area and thus has limitations in providing a sufficient light-supplying area.

SUMMARY

The present invention provides an LED lighting apparatus that can provide a sufficient light-emitting area with a good heat-dissipating property.
The LED lighting apparatus in accordance with an aspect of the present invention includes: a first cover having ventilation holes formed therein; a thermal base having an opening formed on one side thereof and being coupled with the first cover on the other side thereof and having an airflow path for connecting the ventilation holes with the opening formed on an inside thereof and configured to guide flow of air being flowed into the airflow path; LED packages disposed on an outside of the thermal base and configured to dissipate heat by the air flowing through the airflow path; an electric connector being coupled to the first cover and electrically connected with the LED packages; and a second cover covering the LED packages, and the thermal base has a reflective surface formed thereon for reflecting and diffusing at least some of light generated by the LED packages.
The LED lighting apparatus can further include a support board supporting the LED packages on the outside of the thermal base.
The support board can be tightly adhered to an external circumferential surface of the thermal base by means of at least one of interference fitting, tube expanding and shrinkage fitting.
The LED packages can be arranged to be inclined on the outside of the thermal base.
The LED packages can be arranged in pairs along a lengthwise direction of the thermal base, and each pair of LED packages can be inclined in opposite directions in such a way that a radiation angle of light emitted by the pair of LED packages is increased.
The LED lighting apparatus can further include a power supply, which has at least a portion thereof received in the thermal base so as to be placed in the airflow path of the thermal base and is configured to supply electric power to the LED packages.
The power supply can include: a housing coupled to the first cover and having through-holes formed therein for flow of the air; and a printed circuit board being received in the housing.
The LED lighting apparatus can further include a heat-dissipating member disposed on the airflow path of the thermal base and configured to receive heat generated by the LED packages and discharge the heat to the air flowing through the airflow path.
The heat-dissipating member can include a plurality of heat-pipe loops that are formed in a capillary type and in which working fluid is injected, and the heat-pipe loops can include a heat-absorbing portion configured to absorb heat and a heat-dissipating portion configured to discharge the heat absorbed by the heat-absorbing portion.
The plurality of heat-pipe loops can be radially arranged about a center axis of the thermal base.
The second cover can be coupled to the first cover so as to cover the thermal base and the LED packages and can have airflow holes formed therein so as to correspond to a position of the opening.
The LED lighting apparatus can further include a reflector adjacently disposed around the thermal base and configured to reflect light generated by the LED packages or light reflected by the thermal base.
The second cover can be coupled to the thermal base so as to cover the LED packages and can have airflow holes formed therein so as to correspond to a position of the opening.
The ventilation holes can be formed in the thermal base.
One side of the second cover can be formed in a depressed shape in such a way that the airflow holes are inserted into the opening.
The LED lighting apparatus according to the present invention can provide a wide light-emitting area a good heat-dissipating property.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view showing an LED lighting apparatus in accordance with an embodiment of the present invention.
FIG. 2 is an exploded perspective view showing the LED lighting apparatus in accordance with an embodiment of the present invention.
FIG. 3 illustrates how heat is dissipated using air flow in the LED lighting apparatus in accordance with an embodiment of the present invention.
FIG. 4 illustrates how a heat-pipe loop is installed in the LED lighting apparatus in accordance with an embodiment of the present invention.
FIG. 5 shows the heat-pipe loop of the LED lighting apparatus in accordance with an embodiment of the present invention.
FIG. 6 shows the LED lighting apparatus in accordance with an embodiment of the present invention with a support board omitted.
FIG. 7 is a front view showing an LED lighting apparatus in accordance with another embodiment of the present invention.
FIG. 8 is an exploded perspective view showing the LED lighting apparatus in accordance with another embodiment of the present invention.
FIG. 9 illustrates how heat is dissipated using air flow in the LED lighting apparatus in accordance with another embodiment of the present invention.
FIG. 10 illustrates how light is diffused using a reflector in the LED lighting apparatus in accordance with another embodiment of the present invention.
FIG. 11 shows a second cover coupled to a thermal base in the LED lighting apparatus in accordance with an embodiment of the present invention.
FIG. 12 is an exploded perspective view showing the second cover coupled to the thermal base in the LED lighting apparatus in accordance with an embodiment of the present invention.
FIG. 13 illustrates how heat is dissipated using air flow when the second cover is coupled to the thermal base in the LED lighting apparatus in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION

Since there can be a variety of permutations and embodiments of the present invention, certain embodiments will be illustrated and described with reference to the accompanying drawings. This, however, is by no means to restrict the present invention to certain embodiments, and shall be construed as including all permutations, equivalents and substitutes covered by the ideas and scope of the present invention. Throughout the description of the present invention, when describing a certain relevant conventional technology is determined to evade the point of the present invention, the pertinent detailed description will be omitted.
Terms such as "first" and "second" can be used in describing various elements, but the above elements shall not be restricted to the above terms. The above terms are used only to distinguish one element from the other.
The terms used in the description are intended to describe certain embodiments only, and shall by no means restrict the present invention. Unless clearly used otherwise, expressions in a singular form include a meaning of a plural form. In the present description, an expression such as "comprising" or "including" is intended to designate a characteristic, a number, a step, an operation, an element, a part or combinations thereof, and shall not be construed to preclude any presence or possibility of one or more other characteristics, numbers, steps, operations, elements, parts or combinations thereof.
Hereinafter, an LED lighting apparatus in accordance with the present invention will be described with reference to the accompanying drawings. Identical or corresponding elements will be given the same reference numerals, regardless of the figure number, and any redundant description of the identical or corresponding elements will not be repeated.
FIG 1 is a front view showing an LED lighting apparatus 100 in accordance with an embodiment of the present invention. FIG. 2 is an exploded perspective view showing the LED lighting apparatus 100 in accordance with an embodiment of the present invention. FIG. 3 illustrates how heat is dissipated using air flow in the LED lighting apparatus 100 in accordance with an embodiment of the present invention.
According to the present embodiment, as illustrated in FIG. 1 to FIG 3, the LED lighting apparatus 100 includes LED packages 10, a first cover 20, a thermal base 30, a second cover 50, a power supply 60, a support board 80 and an electric connector 90.
According to the present embodiment, the LED lighting apparatus 100 can have air-permeability maximized and a heat-dissipating property further improved, by securing an airflow path 34 using the thermal base 30 disposed at a center axis of the LED lighting apparatus 100 and by disposing the LED packages 10 on an outside of the thermal base 30.
As a higher heat-dissipating property can be provided by use of the thermal base 30 disposed at the center axis of the LED lighting apparatus 100, a significantly smaller quantity of a thermal conductive material, such as aluminum, can be used for making a heat-dissipating structure than the conventional heat sink installed on an entire external circumferential surface of a body to which a light source is coupled, thereby resulting in further saving of the manufacturing cost of the LED lighting apparatus 100.
Moreover, according to the present embodiment, as the LED packages 10 are directly installed on an external circumferential surface of the thermal base 30 through the support board 80, a heat-transfer path for heat-dissipation of the LED packages 10 can be shortened, thereby making it possible to further improve the heat-dissipating property.
According to the present embodiment, a pair of support boards 80 are installed above and below each other on the external circumferential surface of the thermal base 30, and the LED packages 10 are installed on the support boards 80 in such a way that the LED packages 10 are tilted in directions that are opposite to each other (i.e., upwardly on the support board 80 located on an upper side and downwardly on the support board 80 located on a lower side). Accordingly, a range of longitudinal radiation angles of the light emitted by the LED packages 10 disposed above and below each other can be increased.
For example, since the LED packages 10 can radiate the light at an angle of 120 degrees, by disposing the LED packages 10 to be tilted in opposite directions, the LED lighting apparatus 100 can have the light radiated at a wide radiation angle that is similar to the sum of the radiation angles of the LED packages 10.
Moreover, as the plurality of LED packages 10 can be arranged at regular intervals around the external circumferential surface of the thermal base 30, a range of latitudinal radiation angles can be also increased to a radiation angle that is similar to the sum of the radiation angles of the LED packages 10, similarly to the above-described principle.
Hereinafter, the elements of the LED lighting apparatus 100 in accordance with the present embodiment will be described in detail with reference to FIG. 1 to FIG. 5.
The first cover 20 is coupled with the thermal base 30, as illustrated in FIGS. 1 to 3. The first cover 20 has ventilation holes 22, which are connected with the airflow path 34 of the thermal base 30, formed therein. Heat generated by the LED packages 10 can be released to an outside through the airflow path 34 and the ventilation holes 22. The first cover 20 can be made of a highly thermally conductive material, such as aluminum.
In case the LED lighting apparatus 100 is mounted inversely from FIG. 3 in such a way that the electric connector 90 is located at a bottom, the heat of the LED packages 10 can be released to the outside through the airflow path 34 and airflow holes 52 formed in the second cover 50.
As illustrated in FIGS. 1 to 3, the first cover 20 can have the electric connector 90, which is electrically connected with the LED packages 10 through a printed circuit board 63 of the power supply 60, connected at an end portion thereof, and the first cover 20 can have a hemispherical structure in which a hollow space is formed. Here, the electric connector 90 can be a socket having the lamp structure of Edison type, swan type, etc.
As the first cover 20 has the ventilation holes 22 formed in all directions on a spherical surface thereof, the air flowing in latitudinal directions around the first cover 20 can also pass through the first cover 20, thereby improving the heat-dissipating property further.
The thermal base 30 can provide the airflow path 34 required for heat-dissipation of the LED packages 10, as illustrated in FIGS. 1 to 3. That is, the thermal base 30 can have an opening 32 formed on one side thereof, the first cover 20 coupled to the other side thereof, and the airflow path 34 formed at an inside thereof for connecting the opening 32 with the ventilation holes 22, and thus the air flowed into the opening 32 or the ventilation holes 22 can form a flow through the airflow path 34.
As shown in FIG. 3, the thermal base 30 has a hollow cylindrical structure with the opening 32 formed toward an object to be lighted. Moreover, the other side of the thermal base 30 that is coupled with the first cover 20 has an open structure, and thus the airflow path 34 that is connected from the opening 32 to the hollow space of the first cover 20 is formed inside the cylindrical thermal base 30.
Specifically, the thermal base 30 is constituted with a flow guide portion, which is in a circular tube structure having a predetermined diameter, and a connection portion, which is in an expanded tube structure having upwardly-increased diameters, above the flow guide portion. The connection portion is coupled to a lower end of the first cover 20.
As illustrated in FIG. 3, the air flowed into the airflow path 34, which is the hollow space inside, through the opening 32 of the thermal base 30 is heated by the heat generated by the LED packages 10 and transferred through the support board 80 and an inside wall of the thermal base 30 to be elevated naturally and discharged through the ventilation holes 22.
When the air inside the airflow path 34 ascends, new, cold outside air is flowed in through the opening 32 of the thermal base 30 in order to fill the hollow space. In other words, the cold, outside air is flowed in through the opening 32 of the thermal base 30, and the flowed-in air is heated by the LED packages 10 and discharged, creating a continuous flow of air.
In such a case, in order to enhance the heat-dissipating property, the thermal base 30 can be also used as heat-dissipating means. Specifically, in the case of the present embodiment, the thermal base 30 can be made of a highly heat-conductive metal (e.g., aluminum), similarly to the first cover 20.
Accordingly, the air that is flowing through the airflow path 34 comes in contact with the inside wall of the thermal base 30 that is heated by the LED packages 10 and absorbs the heat. That is, the thermal base 30 can discharge the heat transferred from the LED packages 10 to the outside through the air flowing therein.
Moreover, in the case of the present embodiment, the thermal base 30 can have a reflective surface 31 formed thereon for reflecting and diffusing some of the light generated by the LED packages 10. In other words, an external surface of the thermal base 30 can be used as a reflective plate for diffusing the light.
Meanwhile, in order to further enhance the heat-dissipating property, the airflow path 34 of the thermal base 30 can have a heat-dissipating member 40 additionally installed thereon for absorbing the heat generated by the LED packages 10 and discharging the heat through the air flowing through the airflow path 34.
FIG. 4 illustrates how a heat-pipe loop 44 is installed in the LED lighting apparatus 100 in accordance with an embodiment of the present invention. FIG. 5 shows the heat-pipe loop 44 of the LED lighting apparatus 100 in accordance with an embodiment of the present invention.
The heat-dissipating member 40 can absorb the heat generated by the LED packages 10 and discharge the absorbed heat to the air flowing through the airflow path 34. As shown in FIG. 5, used for the heat-dissipating member 40 of the present embodiment can be an oscillating capillary type heat-pipe, which is formed in a capillary type and in which working fluid 42a is injected.
Specifically, as illustrated in FIGS. 4 and 5, the heat-dissipating member 40 of the present embodiment can be constituted by repeatedly arranging the heat-pipe loops 44 that include a heat-absorbing portion 40a, which receives heat by being in contact with the inside wall of the thermal base 30 that is on a side of the LED packages 10, and a heat-dissipating portion 40b, which is separated from the heat-absorbing portion 40a and discharges the heat absorbed by the heat-absorbing portion 40a.
That is, a plurality of heat-pipe loops 44 can have a spiral structure that reciprocates between a portion toward the LED packages 10 within the airflow path 34 and a portion separated above therefrom. Accordingly, a surface area required for heat-dissipation can be maximally provided in a limited space, and thus the air can freely move and absorb the heat of the LED packages 10 through the gaps in between the spiral structure of the plurality of heat-pipe loops 44.
Moreover, the plurality of heat-pipe loops 44 can be radially arranged about a center axis of the thermal base 30. That is, by winding the plurality of heat-pipe loops 44 having the spiral structure in an annular shape, the heat-dissipating portion 40b can be radially disposed. In other words, the heat-dissipating portion 40 that carries out heat-dissipation is radially disposed about a center axis of the annular structure. Accordingly, the flow of air required for heat-dissipation can be freely made, achieving a more efficient heat-dissipation.
Although it is presented in the present embodiment that the plurality of heat-pipe loops 44 have the spiral structure, the present invention is not limited to what has been described herein, and it shall be appreciated that the scope of the present invention also includes a structure in which a plurality of capillary tubes 42, which include a heat-absorbing portion 40a for absorbing the heat and a heat-dissipating portion 40b separated from the heat-absorbing portion 40a and discharging the absorbed heat, are arranged parallel with one another.
As shown in FIG. 4, a separate heat-transfer member can be interposed between the inside wall of the thermal base 30 and the heat-dissipating member 40 so that the inside wall of the thermal base 30 and the heat-absorbing portion 40a of the heat-dissipating member 40 are in contact with each other, and alternatively, coupling grooves can be formed on the inside wall of the thermal base 30 so as to enable coupling with the capillary tubes 42 constituting the heat-pipe loops 44.
In the case of the present embodiment, the plurality of heat-pipe loops 44 can be an oscillating capillary type of heat-pipe loops 44 in which the working fluid 42a is injected. As shown in FIG. 4, the oscillating capillary type heat-pipe loops 44 have a structure in which the working fluid 42a and air bubbles 42b are injected in a predetermined ratio into the capillary tubes 42 and then the capillary tubes 42 are sealed from an outside.
Accordingly, the oscillating capillary tube type heat-pipe loops 44 have a heat-transfer cycle in which heat is mass-transported in the form of latent heat by volume expansion and condensation of the air bubbles 42b and the working fluid 42a. As a result, the heat-dissipating property of the heat-pipe loops 44 can be maximized.
Here, the heat-pipe loops 44 can include capillary tubes 42 that are made of highly thermal-conductive metallic materials, such as copper, aluminum, etc. Accordingly, not only can the heat be conducted quickly, but the volume change of the air bubbles 42b injected therein can be quickly induced.
Moreover, the plurality of heat-pipe loops 44 can be communicated with one another. Here, both an open loop and a close loop are possible for a communication structure of the heat-pipe loops 44. Moreover, all or some of the plurality of heat-pipe loops 44 can be communicated with neighboring heat-pipe loops 44. Accordingly, the plurality of heat-pipe loops 44 can have an entirely open or close loop shape according to design requirement.
Meanwhile, the LED lighting apparatus 100 in accordance with the present embodiment can include the power supply 60 that has at least a portion thereof received inside the thermal base 30 so as to be located in the airflow path 34 of the thermal base 30 and is configured to supply electric power to the LED packages 10. In such a case, the power supply 60 can include a housing 61, which is coupled to the first cover 20, and the printed circuit board 63, which is received in the housing 61, as shown in FIG. 3. The printed circuit board 63 can have various active and passive devices, such as a converter, installed thereon.
By installing the power supply 60 in the airflow path 34 of the thermal base 30, the heat generated by the power supply 60 can be effectively discharged to the outside through the air flowing through the airflow path 34. As described above, since continuous flow of air is formed in the airflow path 34, it is possible to prevent the power supply 60 from overheating and having the performance thereof deteriorated.
As illustrated in FIG 4, the heat-dissipating member 40 can be installed in the airflow path 34, and the heat-dissipating member 40 can form an annular structure to have a ventilation portion 45 formed in the middle thereof. As the power supply 60 can be received in the ventilation portion 45 and placed on a movement path of the air passing through the ventilation portion 45, a more effective heat-dissipation of the power supply 60 becomes possible by this highly ventilated heat-dissipating member 40.
In such a case, the housing 61 of the power supply 60 can have through-holes 62 formed therein for flowing of the air, as shown in FIG. 4. Accordingly, the air flowing through the ventilation portion 45 can be flowed into the housing 61, and thus the heat-dissipating performance of the power supply 60 can be further improved.
As described above, the thermal base 30 of the present embodiment provides a maximal ventilation by having the air flowed into the LED lighting apparatus 100 to realize a high heat-dissipating performance. Moreover, by entirely installing the heat-dissipating structure inside the thermal base 30, an external surface of the LED lighting apparatus 100 can be used for other purposes than heat-dissipation.
As described above, by being disposed on the outside of the thermal base 30, the LED packages 10 can have the heat thereof dissipated by the air flowing through the airflow path 34. The LED packages 10 can emit the light by use of electrical energy and can be realized as a package board or a packaged LED chip that is mounted on the package board.
The LED packages 10 can be arranged to be inclined on the outside of the thermal base 30. The LED packages 10 can be arranged in pairs along a lengthwise direction (i.e., in an up-down direction in the drawing) of the thermal base 30, and a pair of LED packages 10 can be inclined in opposite directions to each other (i.e., upwardly for the LED package 10 located on an upper side and downwardly for the LED package 10 on a lower side) so that a range of longitudinal radiation angles of the light emitted by the LED packages 10 can be increased.
Specifically, the LED packages 10 on the upper side can be disposed to be inclined upwardly by less than 90 degrees on the external circumferential surface of the thermal base 30, and the LED packages 10 on the lower side can be disposed to be inclined downwardly by less than 90 degrees on the external circumferential surface of the thermal base 30. Accordingly, effective surfaces of the upper side LED packages 10 and the lower side LED packages 10 face an upper diagonal direction and a lower diagonal direction, respectively.
Since the LED packages 10 have a radiation angle of, for example, 120 degrees, the LED lighting apparatus 100 can emit the light in a wide longitudinal radiation angle that is similar to the sum of the radiation angles of the upper and lower side LED packages 10, depending on how the LED packages 10 are arranged.
The LED packages 10 can be arranged in plurality at regular intervals around the external circumferential surface of the thermal base 30. For instance, four LED packages 10 can be arranged at regular intervals. Accordingly, a range of latitudinal radiation angles can be also increased to a radiation angle that is similar to the sum of the radiation angles of the LED packages 10, similarly to the above-described principle.
In the present embodiment, while the plurality of LED packages 10 are arranged at regular intervals around the external circumferential surface of the thermal base 30, the plurality of LED packages 10 can be disposed on an upper layer of a virtual plane perpendicular to the center axis of the thermal base 30 so as to be tilted by a predetermined angle from the external circumferential surface of the thermal base 30, and an additional plurality of LED packages 10 can be disposed on a lower layer of the virtual plane so as to be symmetrical with the LED packages 10 on the upper layer. Accordingly, the upper side LED packages 10 and the lower side LED packages 10 can be oriented in an upper diagonal direction and a lower diagonal direction, respectively.
According to the above-described arrangement of the LED packages 10, an overall radiation surface of the light emitted from the LED lighting apparatus 100 becomes nearly a sphere, thereby maximizing an area to which the light is supplied by the LED lighting apparatus 100.
The LED packages 10 can be supported on the outside of the thermal base 30 by the support board 80. By having the LED packages 10 installed directly on the external circumferential surface of the thermal base 30 through the support board 80, the heat-transfer path for heat-dissipation of the LED packages 10 can be shortened, thereby making it possible to further improve the heat-dissipating property of the LED packages 10.
In such a case, the support board 80 can be a circuit board that is constituted with a base substrate made of a highly thermal-conductive material, such as aluminum, an insulation layer formed on a surface of the base substrate, and a circuit pattern formed on the insulation layer and electrically connecting the LED packages 10 with a printed circuit board of the power supply 60.
As such, as the support board 80 includes the base substrate made of a highly thermal-conductive metal, the heat of the LED packages 10 can be effectively transferred to the inside wall of the thermal base 30 through the support board 80.
Specifically, the support board 80 can be constituted with a joint portion 82, which is coupled to the thermal base 30 and has an annular structure so as to be fitted on the external circumferential surface of the thermal base 30, and a support portion 84, which is extended from the joint portion 82 and has the LED packages 10 coupled thereto.
The support portion 84 can be bent from the joint portion 82 so as to be inclined by a predetermined angle from the external circumferential surface of the thermal base 30 and thus can have a surface that is sloped from the center axis of the thermal base 30. By having the LED packages 10 coupled to the sloped surface, the effective surfaces of the LED packages 10 can be oriented in an upper diagonal direction or a lower diagonal direction.
In such a case, the support board 80 can be coupled to be in tight contact the external circumferential surface of the thermal base 30. By having the support board 80 to be in tight contact with the thermal base 30, not only can the heat generated by the LED packages 10 be transferred to the thermal base more effectively through the support board 80, but the support board 80 can be fixed more securely on the external circumferential surface of the thermal base 30.
The support board 80 can be tightly adhered and fixed to the external circumferential surface of the thermal base 30 by means of interference fitting, tube expanding, shrinkage fitting, or a combination thereof.
Specifically, in the interference fitting method, an internal diameter of the joint portion 82 of the support board 80 can be designed to be smaller than an external diameter of the thermal base 30, and the thermal base 30 can be inserted into the joint portion 82, thereby tightly adhering and fixing the support board 80 to the thermal base 30.
In the tube expanding method, a ball-shaped tube expanding means is inserted into the thermal base 30 while the thermal base 30 is inserted in the joint portion 82 of the support board 80, and a diameter of a portion of the thermal base 30 where the joint portion 82 is located is expanded to have the support board 80 tightly adhered and fixed.
In the shrinkage fitting method, after heating and expanding the support board 80 and/or cooling and contracting the thermal base 30, the thermal base 30 is inserted into the joint portion 82 of the support board 80. Then, by leaving the thermal base 30 inserted in the joint portion 82 of the support board 80, the contracted support board 80 or thermal base 30 is returned to its original state to have the support board 80 tightly adhered and fixed.
Meanwhile, as illustrated in FIG. 6, it is possible to omit the support board 80 and have the LED packages 10 directly installed on the external circumferential surface of the thermal base 30. By having the LED packages 10 installed directly on the thermal base 30, the heat-transfer path can be further shortened to further improve the heat-dissipating property, and the production cost can be further saved due to the absence of the support board 80.
The second cover 50 can protect internal components and induce an efficient flow of air. The second cover 50 can be made of a transparent material so as to allow the light to transmit. As illustrated in FIGS. 1 to 3, the second cover 50 is coupled to the first cover 20 so as to cover the thermal base 30 and the LED packages 10 and has the airflow holes 52 formed therein in correspondence with a position of the opening 32.
The second cover 50 is formed to envelop lateral sides and lower side of the LED lighting apparatus 100 so as to cover the LED packages 10 and the thermal base 30 and thus protects the LED packages 10 and the thermal base 30 from any impact and contamination from the outside.
Moreover, the airflow holes 52 formed in the lower portion of the second cover 50 are formed to correspond to the position of the opening 32 of the thermal base 30 and thus function to guide the cold, outside air into the airflow path 34 as soon as an ascending airflow is formed in the airflow path 34.
Although it is described in the case of the present embodiment that the LED packages 10 and the thermal base 30 are both covered by the second cover 50, it is also possible that the second cover 50 is provided in a small size and installed on the external circumferential surface of the thermal base 30 so as to cover the LED packages only 10.
Specifically, the configuration of how the second cover 50 is coupled to the thermal base 30 in the LED lighting apparatus 100 in accordance with the present embodiment will be described with reference to FIGS. 11 to 13.
FIG. 11 shows the second cover coupled to the thermal base in the LED lighting apparatus in accordance with an embodiment of the present invention. FIG. 12 is an exploded perspective view showing the second cover coupled to the thermal base in the LED lighting apparatus in accordance with an embodiment of the present invention. FIG. 13 illustrates how the heat is dissipated using air flow when the second cover is coupled to the thermal base in the LED lighting apparatus in accordance with an embodiment of the present invention.
As illustrated in FIGS. 11 to 13, in the LED lighting apparatus 100 in accordance with the present embodiment, the second cover 50 can be coupled to the thermal base 30 so as to cover the LED packages 10 and have the airflow holes 52 formed to correspond to the position of the opening 32.
That is, the second cover 50 can be coupled to a lower end portion of the thermal base 30 to cover a minimal portion of the thermal base 30. As a result, the LED packages 10 can be suitably protected from the impact and contamination from the outside even though the minimal portion of the thermal base 30 is covered.
Accordingly, a relatively large area of the thermal base 30 can be in direct contact with outside air, and thus the heat-dissipating property through the thermal base 30 can be further enhanced. Moreover, since the second cover 50 can be readily detached, the second cover 50 can be easily replaced when the second cover 50 is damaged, and thus the structure of the LED lighting apparatus 100 in accordance with the present embodiment can be simplified and modularized.
In such a case, as illustrated in FIG. 13, a hole is also formed at a lower end portion of the housing 61, and the air flowed into the airflow holes 52 can efficiently dissipate the heat from the power supply 60. Moreover, as shown in FIG 13, the LED packages 10 can be installed inside the second cover 50.
Here, the ventilation holes 22 can be formed on the thermal base 30. Specifically, the ventilation holes 22 can be formed at a portion of the thermal base 30 that is not covered by the second cover 50, instead of the first cover 20. Accordingly, the ventilation holes 22 can form an airflow path that is similar to the case when the ventilation holes 22 are formed in the first cover 20, thereby enabling an efficient heat-dissipation.
Moreover, one side of the second cover 50 can be formed in a depressed shape in such a way that the airflow holes 52 are inserted into the opening 32. That is, a portion of the lower end portion of the second cover 50 where the airflow holes 52 are formed is formed in a depressed shape so that the portion of the lower end portion of the second cover 50 where the airflow holes 52 are formed can be inserted into the opening 32 of the thermal base 30 when the second cover 50 is coupled with the thermal base 30.
Accordingly, the second cover 50 and the thermal base 30 can be coupled to each other more securely, and the airflow path can be provided in a more stable fashion.
As described above, the LED lighting apparatus 100 in accordance with the present embodiment can not only provide the essential heat-dissipating property for the LED packages 30 by use of the thermal base 30 but also diffuse the light evenly to realize an LED lighting without glare.
Hereinafter, an LED lighting apparatus 100 in accordance with another embodiment of the present invention will be described with reference to FIGS. 7 to 10.
FIG. 7 is a front view showing an LED lighting apparatus 100 in accordance with another embodiment of the present invention. FIG. 8 is an exploded perspective view showing the LED lighting apparatus 100 in accordance with another embodiment of the present invention. FIG 9 illustrates how heat is dissipated using air flow in the LED lighting apparatus 100 in accordance with another embodiment of the present invention.
As illustrated in FIGS. 7 to 9, presented in the case of the present embodiment is the LED lighting apparatus 100 that includes LED packages 10, a first cover 20, a thermal base 30, a second cover 50, a power supply 60, a heat-dissipating member 40, a reflector 70, an electric connector 90 and a support board 80.
According to the present embodiment, the LED lighting apparatus 100 can have air-permeability maximized and a heat-dissipating property further improved, by securing an airflow path 34 using the thermal base 30 disposed at a center axis of the LED lighting apparatus 100 and by disposing the LED packages 10 on an outside of the thermal base 30.
As a higher heat-dissipating property can be provided by use of the thermal base 30 disposed at the center axis of the LED lighting apparatus 100, a significantly smaller quantity of a thermal conductive material, such as aluminum, can be used for making a heat-dissipating structure than the conventional heat sink installed on an entire external circumferential surface of a body to which a light source is coupled, thereby resulting in further saving of the manufacturing cost of the LED lighting apparatus 100.
Moreover, according to the present embodiment, the LED packages 10 are coupled to a lower surface of the first cover 20, and a surface of the thermal base 30 is provided as a reflective surface 31 so as to reflect and diffuse at least some of the light generated from the LED packages 10, and thus a radiation surface of the light emitted from the LED lighting apparatus 100 can be further expanded.
Hereinafter, elements of the LED lighting apparatus 100 will be described in more detail with reference to FIGS. 7 to 10.
The LED packages 10 can emit light by use of electrical energy, and can be constituted with a package board and an LED chip mounted and packaged on the package board. As shown in FIG. 8, in the case of the present embodiment, the LED packages 10 are mounted on the support board 80, which is installed in the first cover 20.
The support board 10 can be formed in an annular structure and coupled to the lower surface of the first cover 20, and a plurality of LED packages 10 are distributed and arranged on the support board 80 in such a way that an effective surface thereof is oriented vertically downward.
The first cover 20 can receive the heat generated by the LED packages 10 and directly discharge the received heat or transfer the heat to the heat-dissipating member 40. For this, the LED packages 10 is coupled to a boundary area 21 on a lower surface of the first cover 20 so as to enable heat-transfer, and the first cover 20 is made of a highly thermal conductive metal, such as aluminum. Moreover, the first cover 20 can have ventilation holes 22 formed therein, enabling heat-dissipation by the flow of air passing through the first cover 20.
As illustrated in FIGS. 7 to 9, the base 20 can have the electric connector 90, which is electrically connected with the power supply 60, connected at an end portion thereof, and the first cover 20 can have a hemispherical structure in which a hollow space is formed.
Accordingly, the heat generated by the LED packages 10 is transferred through a spherical surface of the first cover 20, and the air moving through the airflow path 34 of the thermal base 30 is flowed into the hollow space of the first cover 20 and then discharged to an outside through the ventilation holes 22, thereby discharging the heat of the first cover 20 to the outside.
Meanwhile, since the spherical surface of the first cover 20 has the ventilation holes 22 formed in every direction, the air flowing in latitudinal directions around the first cover 20 can also pass through the first cover 20, thereby further improving the heat-dissipating property.
As illustrated in FIGS. 7 to 9, the thermal base 30 can provide the airflow path 34 required for heat-dissipation of the LED packages 10. Specifically, since the thermal base 30 can have an opening 32 formed on one side thereof, be coupled with the first cover 20 on the other side thereof, and have the airflow path 34 formed on an inside thereof for connecting the opening 32 with the ventilation holes 22, the air flowed into the opening 32 or the ventilation holes 22 can form a flow through the airflow path 34.
As shown in FIG. 9, the thermal base 30 has a structure of a hollow cylinder in which the opening 32 is formed toward an object to be lighted. Moreover, by allowing the other side of the thermal base 30 that is coupled with the first cover 20 to have an open structure as well, the airflow path 34 being connected form the opening to the hollow space of the electric connector 90 is formed inside the cylindrical thermal base 30.
As indicated in FIG. 9, the air flowed into the airflow path 34, which is the hollow space therein, through the opening 32 of the thermal base 32 is heated by the heat from the first cover 20 that is heated by the LED packages 10 to ascend naturally and be discharged through the ventilation holes 22.
When the air inside the airflow path 34 ascends, new, cold outside air is flowed in through the opening 32 of the thermal base 30 in order to fill the hollow space. In other words, the cold, outside air is flowed in through the opening 32 of the thermal base 30, and the flowed-in air is heated by the LED packages 10 and the first cover 20 and discharged, creating a continuous flow of air.
In such a case, in order to enhance the heat-dissipating property, the thermal base 30 can be also used as heat-dissipating means. Specifically, in the case of the present embodiment, the thermal base 30 can be made of a highly heat-conductive metal (e.g., aluminum), similarly to the first cover 20.
Accordingly, the air that is flowing through the airflow path 34 comes in contact with an inside wall of the thermal base 30 and absorbs the heat. That is, the thermal base 30 can discharge the heat transferred from the LED packages 10 and the first cover 20 to the outside through the air flowing therein.
Moreover, in order to further enhance the heat-dissipating property, the heat-dissipating member 40 can be additionally installed in the airflow path 34 of the thermal base 30. The heat-dissipating member 40 is coupled to the first cover 20 and functions to absorb the heat generated by the first cover 20 and discharge the absorbed heat through the air flowing through the airflow path 34.
As shown in FIG 9, used for the heat-dissipating member 40 of the present embodiment can be an oscillating capillary type heat-pipe, which is formed in a capillary type and in which working fluid 42a is injected.
Specifically, the heat-dissipating member 40 of the present embodiment can be constituted by repeatedly arranging heat-pipe loops 44 that include a heat-absorbing portion 40a, which receives heat by being coupled to the first cover 20, and a heat-dissipating portion 40b, which is separated from the heat-absorbing portion 40a and discharges the heat absorbed by the heat-absorbing portion 40a.
That is, a plurality of heat-pipe loops 44 can have a spiral structure that reciprocates between a portion toward the first cover 20 within the airflow path 34 and a portion separated below therefrom. Accordingly, a surface area required for heat-dissipation can be maximally provided in a limited space, and thus the air can freely move and absorb the heat of the LED packages 10 through the gaps in between the spiral structure of the plurality of heat-pipe loops 44.
Moreover, the plurality of heat-pipe loops 44 can be radially arranged about a center axis of the thermal base 30. That is, by winding the plurality of heat-pipe loops 44 having the spiral structure in an annular shape, the heat-dissipating portion 40b can be radially disposed. In other words, the heat-dissipating portion 40 that carries out heat-dissipation is radially disposed about a center axis of the annular structure. Accordingly, the flow of air required for heat-dissipation can be freely made, achieving a more efficient heat-dissipation.
As shown in FIG. 8, coupling grooves 24 can be formed on an inside of the first cover so as to enable coupling with capillary tubes 42 constituting the heat-pipe loops 44. Accordingly, the heat-pipe loops 44 can be securely coupled to the first cover 20, and a heat-transfer area, by which the heat is transferred from the first cover 20 to the heat-pipe loops 44, can be increased.
Although it is presented in the present embodiment that the plurality of heat-pipe loops 44 have the spiral structure, the present invention is not limited to what has been described herein, and it shall be appreciated that the scope of the present invention also includes a structure in which a plurality of capillary tubes 42, which include a heat-absorbing portion 40a for absorbing the heat and a heat-dissipating portion 40b separated from the heat-absorbing portion 40a and discharging the absorbed heat, are arranged parallel with one another.
In the case of the present embodiment, the plurality of heat-pipe loops 44 can be an oscillating capillary type of heat-pipe loops 44 in which the working fluid 42a is injected. The oscillating capillary type heat-pipe loops 44 have a structure in which the working fluid 42a and air bubbles 42b are injected in a predetermined ratio into the capillary tubes 42 and then the capillary tubes 42 are sealed from an outside.
Accordingly, the oscillating capillary tube type heat-pipe loops 44 have a heat-transfer cycle in which heat is mass-transported in the form of latent heat by volume expansion and condensation of the air bubbles 42b and the working fluid 42a. As a result, the heat-dissipating property of the heat-pipe loops 44 can be maximized.
Here, the heat-pipe loops 44 can include capillary tubes 42 that are made of highly thermal-conductive metallic materials, such as copper, aluminum, etc. Accordingly, not only can the heat be conducted quickly, but the volume change of the air bubbles 42b injected therein can be quickly induced.
Moreover, the plurality of heat-pipe loops 44 can be communicated with one another. An open loop and a close loop are both possible for a communication structure of the heat-pipe loops 44. Moreover, all or some of the plurality of heat-pipe loops 44 can be communicated with neighboring heat-pipe loops 44. Accordingly, the plurality of heat-pipe loops 44 can have an entirely open or close loop shape according to design requirement.
Meanwhile, the LED lighting apparatus 100 in accordance with the present embodiment can include the power supply 60 that supplies electric power to the LED packages 10 by use of the highly air-permeable heat-dissipating member 40.
In the present embodiment, the heat-dissipating member 40 can have a ventilation portion 45, which opens a middle portion of the first cover 20, formed therein, and the power supply 60 can be disposed inside the ventilation portion 45 and placed on a movement path of the air passing through the ventilation portion 45.
Accordingly, the power supply 60 can be naturally heat-dissipated by being in contact with the air passing through the heat-dissipating member 40. That is, since a continuous flow of ascending air is formed in the ventilation portion 45 around the power supply 60, the power supply 60 can be heat-dissipated by this air flow and can be prevented from overheating and having its performance deteriorated.
As described above, the thermal base 30 of the present embodiment provides a maximal ventilation by having the air flowed into the LED lighting apparatus 100 to realize a high heat-dissipating performance. Moreover, by entirely installing the heat-dissipating structure inside the thermal base 30, an external surface of the LED lighting apparatus 100 can be used for other purposes than heat-dissipation.
In the case of the present embodiment, the thermal base 30 can have the reflective surface 31 formed thereon for reflecting and diffusing some of the light generated by the LED packages 10. In other words, an external surface of the thermal base 30 can be used as a reflective plate for diffusing the light.
Specifically, since the LED packages 10 can be disposed on an outside of the thermal base 30, and an outside surface of the thermal base 30 can function as the reflective surface 313 for reflecting the light, the light emitted from the LED packages 10 can be uniformly diffused through the reflective surface 31 of the thermal base 30. As a result, it becomes possible to prevent a glare caused by having the light of the LED packages converged in one direction and to adjust the diffusion of the light to a required range.
The thermal base 30 is formed in a cylindrical shape, and an external circumferential surface of the thermal base 30 can be made of a light-reflective material so as to become the reflective surface 31. Accordingly, some of the light generated by the LED packages 10 can be reflected by the reflective surface 31 of the thermal base 30 that is adjacent to the LED packages 10, and the reflected light can be widely diffused by being reflected in a direction away from the thermal base 30.
Here, so as for the external circumferential surface of the thermal base 30 to become the reflective surface 31, the thermal base 30 can be made of a light-reflective material, or a reflective material can be coated on the external circumferential surface of the thermal base 30.
Moreover, the external circumferential surface of the thermal base 30 can have various angles of reflection according to the range of diffusion required for lighting. For instance, in the case where the external circumferential surface of the thermal base 30 is formed as a curved surface, the curvature of the external circumferential surface can be adjusted to variously modify the angle of reflection.
In the present embodiment, the thermal base 30 has a circular shape of cross-section, of which diameter is decreased toward a bottom thereof, and thus the light generated by the LED packages 10 that are downwardly coupled to the boundary area 21 on the lower surface of the first cover 20 is reflected and diffused by the external circumferential surface of the thermal base 30.
Moreover, the reflector 70 for re-reflecting the light reflected by the thermal base 30 can be additionally installed to provide more various diffusion effects of the light.
FIG. 15 illustrates how light is diffused using the reflector 70 in the LED lighting apparatus 100 in accordance with another embodiment of the present invention.
As shown in FIG 15, the present embodiment can additionally have the reflector 70 that is adjacently disposed around the thermal base 30 and reflects the light generated by the LED packages 10 or the light reflected by the thermal base 30.
Since a reflective surface 72 inside the reflector 70 can re-reflect the light that is primarily reflected by the reflective surface 31, it becomes possible to light a shaded area that could not be lighted by use of the LED packages 10 and the thermal base 30 only. Moreover, it becomes possible to prevent the light reflected by the thermal base 30 from being excessively diffused.
The second cover 50 can protect internal components and induce an efficient flow of air. The second cover 50 can be made of a transparent material so as to allow the light to transmit. As illustrated in FIGS. 7 to 9, the second cover 50 is coupled to the first cover 20 so as to cover the thermal base 30 and the LED packages 10 and has airflow holes 52 formed therein in correspondence with a position of the opening 32.
The second cover 50 is formed to envelop lateral sides and lower side of the LED lighting apparatus 100 so as to cover the LED packages 10 and the thermal base 30 and thus protects the LED packages 10 and the thermal base 30 from any impact and contamination from the outside.
Moreover, the airflow holes 52 formed in the lower portion of the second cover 50 are formed to correspond to the position of the opening 32 of the thermal base 30 and thus function to guide the cold, outside air into the airflow path 34 as soon as an ascending airflow is formed in the airflow path 34.
As described above, the LED lighting apparatus 100 in accordance with the present embodiment can not only provide the essential heat-dissipating property for the LED packages 30 by use of the thermal base 30 but also diffuse the light evenly to realize an LED lighting without glare.
While the present invention has been described with reference to certain embodiments, the embodiments are for illustrative purposes only and shall not limit the invention. It is to be appreciated that those skilled in the art can change or modify the embodiment without departing from the scope and spirit of the invention. It shall be also appreciated that a very large number of embodiments other than that described herein are possible within the scope of the present invention, which shall be defined by the claims appended below.

DESCRIPTION OF ELEMENTS

100: LED lighting apparatus
10: LED packages
20: first cover
22: ventilation holes
24: coupling grooves
30: thermal base
31: reflective surface
32: opening
34: airflow path
40: heat-dissipating member
40a: heat-absorbing portion
40b: heat-dissipating portion
42: capillary tubes
42a: working fluid
42b: air bubbles
44: heat-pipe loops
45: ventilation portion
50: second cover
52: airflow holes
60: power supply
61: housing
62: through-holes
63: printed circuit board
70: reflector
72: reflective surface
80: support board
82: joint portion
84: support portion
90: electric connector

Claims

An LED lighting apparatus comprising:
a first cover having ventilation holes formed therein;

a thermal base having an opening formed on one side thereof and being coupled with the first cover on the other side thereof and having an airflow path for connecting the ventilation holes with the opening formed on an inside thereof and configured to guide flow of air being flowed into the airflow path;

LED packages disposed on an outside of the thermal base and configured to dissipate heat by the air flowing through the airflow path;

an electric connector being coupled to the first cover and electrically connected with the LED packages; and

a second cover covering the LED packages,

wherein the thermal base has a reflective surface formed thereon for reflecting and diffusing at least some of light generated by the LED packages.
The LED lighting apparatus of claim 1, further comprising a support board supporting the LED packages on the outside of the thermal base.
The LED lighting apparatus of claim 2, wherein the support board is tightly adhered to an external circumferential surface of the thermal base by means of at least one of interference fitting, tube expanding and shrinkage fitting.
The LED lighting apparatus of claim 1, wherein the LED packages are arranged to be inclined on the outside of the thermal base.
The LED lighting apparatus of claim 4, wherein the LED packages are arranged in pairs along a lengthwise direction of the thermal base, and
wherein each pair of LED packages are inclined in opposite directions in such a way that a radiation angle of light emitted by the pair of LED packages is increased.
The LED lighting apparatus of claim 1, further comprising a power supply, having at least a portion thereof received in the thermal base so as to be placed in the airflow path of the thermal base, and configured to supply electric power to the LED packages.
The LED lighting apparatus of claim 6, wherein the power supply comprises:
a housing coupled to the first cover and having through-holes formed therein for flow of the air; and

a printed circuit board being received in the housing.
The LED lighting apparatus of claim 1, further comprising a heat-dissipating member disposed on the airflow path of the thermal base and configured to receive heat generated by the LED packages and discharge the heat to the air flowing through the airflow path.
The LED lighting apparatus of claim 8, wherein the heat-dissipating member comprises a plurality of heat-pipe loops that are formed in a capillary type and in which working fluid is injected, the heat-pipe loops comprise a heat-absorbing portion configured to absorb heat and a heat-dissipating portion configured to discharge the heat absorbed by the heat-absorbing portion.
The LED lighting apparatus of claim 9, wherein the plurality of heat-pipe loops is radially arranged about a center axis of the thermal base.
The LED lighting apparatus of claim 1, wherein the second cover is coupled to the first cover so as to cover the thermal base and the LED packages and has airflow holes formed therein so as to correspond to a position of the opening.
The LED lighting apparatus of claim 1, further comprising a reflector adjacently disposed around the thermal base and configured to reflect light generated by the LED packages or light reflected by the thermal base.
The LED lighting apparatus of claim 1, wherein the second cover is coupled to the thermal base so as to cover the LED packages and has airflow holes formed therein so as to correspond to a position of the opening.
The LED lighting apparatus of claim 13, wherein the ventilation holes are formed in the thermal base.
The LED lighting apparatus of claim 13, wherein one side of the second cover is formed in a depressed shape in such a way that the airflow holes are inserted into the opening.