1. Technical Field
The invention relates to illumination devices and particularly to LED based illumination devices.
2. Background Art
Illumination devices such as incandescent bulb and fluorescent light tube based illumination fixtures have been widely used in offices areas and in households. A fluorescent light tube based illumination fixtures normally comprises a lighting fixture having two adaptors fixed at predetermined distance, and a fluorescent light tube secured by the two adaptors and electrically connected with the two adaptors, the two adaptors are connected to the AC power through a ballast. Traditional Fluorescent light tube based illumination fixtures may also comprises a starter to provide the initial ionization voltage. Although fluorescent light tube based illumination fixtures such as lighting panels can provide evenly distributed light and have been widely fitted in offices areas and commercial venues in the form of light boxes and/or lighting arrays, the fact that the fluorescent light tube itself contains mercury make it a potential hazard to the environment and is therefore difficult to be safely disposed or can only be disposed at high cost.
Compact fluorescent lamp (CFL), is another form of fluorescent tube based illumination device which can provide equal illumination effect with less power consumption and is therefore also called energy saving lamp. A compact fluorescent lamp uses a tube which is curved or folded to fit into the space of an incandescent bulb, and a compact electronic ballast in the base of the lamp. Still due to the mercury in the tube, the lamp of this type is not environment friendly.
Recently, with maturation of LED technology, lifecycle of a LED component is increasing while the unit cost is dropping. Benefit from the cost reduction, attempts have been made to incorporate LED components into fixtures of traditional incandescent bulb shape to form LED bulbs or of traditional fluorescent light tube shape to form LED tubes. For LED components however, heat dissipation is always a key issue as only about 15% of the input power is converted into light whereas nearly 85% of the input power is converted into heat. Lift cycle of a LED component can be significantly reduced and the stability of the LED component can be degraded due to high LED junction temperature if heat generated by the LED component cannot be dissipated efficiently
A common means in the art to control heat dissipation of LED bulb or LED tube within an acceptable range is to limit the number of LED components contained in a LED bulb or LED tube, therefore, LED bulbs or LED tubes in the market normally have low output power due to limited number of LED components contained. As a result, it is difficult to achieve energy saving and low cost at the same time since more LED bulbs or LED tubes need to be used to realize the same illumination effect.
Typically, due to insufficient heat dissipation of the LEDs and the LED driver integrated within the tubular body, a low power output LED tube in the shape of a fluorescent tube can only has an output in the range of 15 W to 22 W. Therefore, in order to replace the fluorescent tubes in a traditional lighting panel with four fluorescent tubes, at least four LED tubes are required (20 W×4=80 W) are required to provide same lumen with relatively lower energy. However, four LED tubes can be costly which may be an obstacle for the replacement of fluorescent tubes with LED tubes.
Moreover, retrofitting of the LED tubes in the prior art to a traditional lighting panel can be time consuming and arduous because new LED driver has to be added and the wires has to be rerouted.
Therefore, there is a need in the art for an improved LED lighting fixture having an output power that can generate similar or even higher lumen compared with four fluorescent light tubes and can therefore replace four traditional fluorescent light tubes or four low power LED tubes.
Various embodiment of the invention direct to solutions to the above problems.
According to one aspect of the invention, a heat sink casing is proposes. The heat sink casing can comprises a base made from thermo conductive materials which can comprises a seat portion for coupling at least one LED bar; and a back plate made also from thermo conductive materials, which coupled to the base and is provided with an interface for retrofitting to a traditional lighting fixture.
In some embodiment of the invention, the interface can comprise a magnetic interface. In more preferred embodiment, the interface can alternatively or additionally comprise at least one mounting hole though which the back plate is fastened to the base of the traditional lighting panel or to a ceiling.
In some embodiments, the seat portion can be configured to be receivable of a plurality of LED bars arranged in a herringbone, a triangle, a rectangular column, a polygonal column, a semi-sphere, a cylinder, or a half-cylinder.
In some embodiments, the seat portion can comprise at least one slot for receiving the at least one LED bar. In more preferred embodiments, the seat portion can comprise two slots for receiving two LED bars, wherein the two slots incline from their sides adjoined to one another to their sides distance to one another.
In preferred embodiments, the base can further comprise a web portion, a first sidewall elevated from the web portion and pivotably coupled to a side of the back plate; and a second sidewall elevated from the web portion and securable to an opposite side of the back plate.
Another aspect of the present disclosure may involve an improved LED lighting fixture. In some embodiments, the LED lighting fixture can comprise a heat sink casing which comprises an elongated base having a seat portion for receiving at least one LED bar; and a back plate coupled to the base and provided with an interface to a base of a traditional lighting panel; wherein both the base and the back plate are made from a thermal conductive material; at least one LED bar received in the seat portion; at least one LED driver, coupled to the LED bar; and a diffusion cover coupled to the heat sink casing for diffusing the light emitted by the LED bar.
Similarly, the interface can comprise a magnetic interface. More preferably, the interface can comprise at least one mounting hole though which the back plate can be fastened to the base member of the traditional lighting panel or to a ceiling.
In some embodiments, the seat portion can be configured to be receivable of a plurality of LED bars arranged in a herringbone, a triangle, a rectangular column, a polygonal column, a semi-sphere, a cylinder, or a half-cylinder.
In some embodiments, the seat portion can comprise at least one slot for receiving the at least one LED bar. In more preferred embodiments, the seat portion can comprise two slots for receiving two LED bars, wherein the two slots incline from their sides adjoined to one another to their sides distance to one another.
In some embodiments, the base can further comprise a web portion, a first sidewall elevated from the web portion and pivotably coupled to a side of the back plate; and a second sidewall elevated from the web portion and securable to an opposite side of the back plate.
In some embodiments, the LED lighting fixture can further comprise a front cover affixed to a front end of the base and a rear cover affixed to a rear end of the base so that a chamber can be formed.
In most preferred embodiments, the front cover and the rear cover are affixed on the base with screws which act as pins for pivotably coupling the back plate and the first sidewall.
In other embodiments, at least one of the front cover and the rear cover is provided with an opening for connecting wires of the LED driver to extend through.
In some embodiments, the LED lighting fixture can further comprise a fan assembly attached to an opening provided on at least one of the front cover and the rear cover, or on one of the first side wall and the second side wall.
In the above embodiments, the LED bar can comprise a printed circuit board, PCB, by which it is received in the slot of the seat portion; and a plurality of LED components mounted on the printed circuit board; wherein the printed circuit board is coated with high thermal conductive material.
The LEDs on the PCB can be any LED component ready on shelf and can also be newly emerged components, such AC LED or OLED.
The heat sink casing of design turns the casing into an immense heat sink such that heat generated by the LEDs on the LED bar as well as by the LED driver can be quickly and effectively dissipated so that the LEDs as well as the LED driver can work at an ideal temperature which can consequently extend their service life.
Moreover, as the LED lighting fixture no longer contains separate heat sink, the overall size is reduced which can facilitate mounting of the fixture. Also, by employing the heat sink casing, the overall cost of the LED lighting fixture can be reduced.
The length of the heat sink casing can be increased as required and the length of the LED can be increased accordingly. A LED lighting fixture in the length of a standard fluorescent tube can have a minimum output power of 80 W. Thereby, a LED lighting fixture can replace eight traditional fluorescent tubes or eight low output power LED tubes.
In a relatively high temperature working environment, the LED lighting fixture with the fan assembly can be used to enhance heat dissipation efficiency.
In most cases, the LED lighting fixture can be mounted on the ceiling directly as an individual illumination device. In other cases however, the LED lighting fixtures according to some embodiments of the invention can be used to retrofit existing illumination devices, for example, a base member of an existing lighting panel that contains several fluorescent lighting fixtures. The retrofitting process is simple as only two wires of the LED driver need to be connected to the AC electric supply, no other connection is required.
These and other aspects of the present invention are described in the Detailed Description below and the accompanying figures. Other aspects and features of embodiments of the present invention will become apparent to those of ordinary skill in the art upon reviewing the following description of embodiments of the present invention in concert with the figures. While features of the present invention may be discussed relative to certain embodiments and figures, all embodiments of the present invention can include one or more of the features discussed herein. While one or more embodiments may be discussed as having certain advantageous features, one or more of such features may also be used with the various embodiments of the invention discussed herein. In similar fashion, while exemplary embodiments may be discussed below as system or method embodiments, it is to be understood that such exemplary embodiments can be implemented in various devices, systems, and methods of the present invention.
To facilitate an understanding of the principles and features of the various embodiments of the invention, various illustrative embodiments are explained below.
Although exemplary embodiments of the invention are explained in detail as being LED lighting fixture in general, it is to be understood that other embodiments are contemplated. Accordingly, where the terms “LED light fixture,” “LED lighting fixture” and related terms are used throughout this disclosure, it will be understood that other entities, objects, or activities can take the place of these in various embodiments of the invention. It is not intended that the invention is limited in its scope to the details of construction and arrangement of components set forth in the following description or examples. The invention is capable of other embodiments and of being practiced or carried out in various ways. Also, in describing the exemplary embodiments, specific terminology will be resorted to for the sake of clarity.
It must also be noted that, as used in the specification and the appended claims, the singular forms “a,” “an” and “the” include plural references unless the context clearly dictates otherwise. For example, reference to a component is intended also to include composition of a plurality of components. References to a composition containing “a” constituent is intended to include other constituents in addition to the one named. Furthermore, it is intended that each term contemplates its broadest meaning as understood by those skilled in the art and includes all technical equivalents which operate in a similar manner to accomplish a similar purpose.
Ranges may be expressed herein as from “about” or “approximately” or “substantially” one particular value and/or to “about” or “approximately” or “substantially” another particular value. When such a range is expressed, other exemplary embodiments include from the one particular value and/or to the other particular value.
By “comprising” or “containing” or “including” is meant that at least the named compound, element, particle, or method step is present in the composition or article or method, but does not exclude the presence of other compounds, materials, particles, method steps, even if the other such compounds, material, particles, method steps have the same function as what is named.
It is also to be understood that the mention of one or more method steps does not preclude the presence of additional method steps or intervening method steps between those steps expressly identified. Similarly, it is also to be understood that the mention of one or more components in a composition does not preclude the presence of additional components than those expressly identified.
The materials described as making up the various elements of the invention are intended to be illustrative and not restrictive. Many suitable materials that would perform the same or a similar function as the materials described herein are intended to be embraced within the scope of the invention. Such other materials not described herein can include, but are not limited to, for example, materials that are developed after the time of the development of the invention.
As explained above, a problem with traditional LED lighting fixtures are relatively low heat dissipation efficiency. Typically, heat accumulated within a casing of a LED lighting fixture due to low heat dissipation efficiency can expedite the aging procedure of the components contained therein, especially the LED components and the LED driver.
Unlike traditional designs, embodiments of the present invention provide several exemplary LED lighting fixtures that are capable of dissipating most of the heat generated by the LED components in an efficient way.
As shown in
Herein the circuitry necessary for driving the LED components on the LED array is collectively named as a LED driver.
Herein the LED array refers to a type of LED subassembly comprised of a plurality number of LED components or LEDs connected in series, in parallel or a combination of serial and parallel connection on a rigid or flexible substrate in which wires are prefabricated for connecting the LED components or LEDs and an interface is provided for connecting the LED driver introduced above. Examples of the rigid substrate can be a Printed Circuit Board (PCB) or a Printed Wire Board (PWB), example of a flexible substrate can be a Flexible Printed Circuit Board (FPCB). A LED array implemented on a rigid substrate is also called a LED bar, and a LED array implemented on a flexible substrate is also called a LED band. The LED array can be any length and width desired for a particular design. By extending the length and/or the width of the substrate, the total output power of the LED array can be increased.
An exemplary embodiment of the present invention is illustrated in
The base 11 is preferably in an elongated configuration which comprises a web portion 111 and two side walls 112 and 113, i.e. a first sidewall 112 and a second sidewall 113, extended and/or elevated from the web portion 111 so that a channel 115 is formed in the base 11. On an external surface of the web portion, i.e. the surface opposite from the elevation direction of the two side walls, a seat portion 114 is provided for receiving the above mentioned at least one LED array 30. In preferred embodiments, the web portion 111 and the two side walls 112, 113 are integrally formed, e.g. by mold casting. In other embodiments however, they can be separately formed and jointed together by, e.g. fastening or welding. In order to efficiently dissipate heat generated by the at least one LED array, it is important that the web portion 111,the side walls 112 and 113 and the seat portion 114 forming the base are all made from thermo conductive or high thermo conductive materials such as aluminum, copper, aluminum alloy, copper alloy among other things. Alternatively, the base 11 can be made from low thermo conductive materials and is coated with high thermo conductive materials. As a result, expanded heat dissipation areas are constituted by the web portion and the side walls.
In this embodiment, the back plate 12 substantially coextends with the web portion 111 of the base 11 such that it substantially covers the channel of the base 11. The back plate is made from a sheet material identical or similar to the material for the base 11. A member for pivotally coupling the base 11 is provided on a side of the back plate 12, the component can be a pin, a pin hole for a hinge or a seat for a shaft for coupling a complementary member provided on the base 11.
On one sidewall of the base 11, e.g. a first side wall 112, the complementary member is formed or affixed for mating the member on the back plate 12.
The back plate 12 can be further secured to the base 11 via a securing mechanism which can be a snap in fit configuration comprising, for example, a protruding rib 1222 provided along the entire length of a lip portion extended upright from the back plate 12, and a longitudinal slot 1131 for receiving the protruding rib formed on the second sidewall 113 of the base 11, or vise versa. Alternatively, the protrusion 1222 may be several individual protrusions receivable in the slot 1131. The securing mechanism can also be other snap-in fit configurations, notching configurations and fastening configurations for example and not intend to limit.
As shown in the above mentioned Figures, the subassembly formed by the base 11 and the back plate 12 still has two end openings along its longitudinal axis, which can be closed by a front end cover 13 and a rear end cover 14 respectively. Exemplary configurations of the front end cover 13 and the rear end cover 14 are illustrated in
The base 11 in one preferred embodiment of the present invention is illustrated in
The seat portion 114 as illustrated in
As illustrated in
A sectional view of the base 11 and the back plate 12 separated from one another is illustrated in
It is depicted in
A complete lighting fixture which comprises a subassembly of the base 11, the back plate 12 and the two end covers 13, 14, a diffusion cover 20, two LED arrays 30 and a LED driver 40 is illustration in
One of he opening 131, 141 of the front end cover 13 or the rear end cover 14 can be fitted with a fan subassembly to improve dissipation from the casing. Alternatively or additionally, a fan subassembly 15 can be mounted on a one of side walls 112 and 113 of the base 11.
The diffusion cover 20 of the lighting device can be made from any conventional materials in the art, e.g. transparent glass, PVC and Acrylic, or opaque but translucent glass, PVC and Acrylic.
It is preferable that the diffusion cover is configured to a shape that facilitates light diffusion. In the embodiment shown in
In the embodiments shown in
As mentioned above, the configuration of the diffusion cover 20 can be any shape corresponding to the arrangement of LED arrays and the slots for accommodating the LED arrays. Preferably however the diffusion cover 20 has a round hollow tubular body with an opening extends along the entire length of the body, as shown in
In exemplary embodiments as shown in
In another embodiment of the present invention, additionally or alternatively, the back plate 12 can be magnetically couple to a metal, preferably steel or cast iron, base member of a traditional lighting panel. In one example, the back plate can be partially magnetized or completely magnetized so that the back plate can be magnetically couple to the base member of the lighting panel directly. In another example, at least one pair of magnetic bar can be affixed to the back plate, preferably approximate the longitudinal or lateral ends of the back plate, so that the back plate can be magnetically coupled to the base member of the lighting panel via these magnetic bars. The back plate or the magnetic bar can be made from neodymium based magnetic material, and more preferably, it is made from magnetic materials having high temperature performance such as Nd—Fe—Be magnetic material.
As can be appreciated by those skilled in the art, the LED lighting fixture can also be fixedly connected o the base member of a traditional lighting panel 200 via the mounting holes 123 mentioned above.
It can be seen that the LED lighting fixture in the present invention can replace traditional lighting devices such as fluorescent light tubes or LED tubes. More importantly, the heat dissipation efficient can be increased to approximately 100% when the casing in the present inventive is employed. Also, the base member of a traditional lighting panel can be used to assist heat dissipation which makes the design an all-in-one lighting fixture with supreme heat dissipation performance.
In addition to the traditional Fluorescent tube based lighting panel 200, the LED lighting fixture can also be retrofitted to a base member of any lamp fixtures which has a cover to replace the incandescent bulbs or CFL bulbs in the cover.
The fabricating process of retrofitting the present LED lighting fixture to the lighting panel 200 is also simplified when compared with the low power LED tube in the art. As shown in
Number | Date | Country | Kind |
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201410005468.X | Jan 2014 | CN | national |
201420006843.8 | Jan 2014 | CN | national |
Filing Document | Filing Date | Country | Kind |
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PCT/CN14/70337 | 1/8/2014 | WO | 00 |