This application is a U.S. National phase entry under 35 U.S.C. § 371 of International Application No. PCT/EP2017/051182, filed on Jan. 20, 2017, which claims priority to Chinese Patent Application 201610041814.9, filed on Jan. 22, 2016. Each of these patent applications is incorporated by reference herein in its entirety.
This application relates to an LED (light-emitting diode) lighting device, and particularly to an LED lighting device which has a compact structure and is convenient to install, and a method for manufacturing the LED lighting device.
As is well known, LED lighting has many irreplaceable advantages, so LED is more and more used as a light source of a lighting device for replacing a conventional light source. An LED tube is a main product employed in an indoor LED lighting device. Compared with a conventional daylight tube and a fluorescent tube, the LED tube has a higher lumen efficiency and a longer service life, and is more energy-saving and environment-friendly. Furthermore, an LED tube does not require a ballast or a starter, and is easy to implement modular manufacture and installation. So LED tube has been increasingly popular and has been employed in various aspects of production and life.
For an LED lighting device, an external power supply is generally applied to the LED light-emitting unit via an LED driver as an LED constant-current driving source to allow LED to emit light. Conventionally, the LED driver is constituted by a drive circuit including multiple electronic components, and is electrically connected as an integral piece in a form of a separate package or a circuit board to the LED circuit board of the LED light-emitting unit in the housing. Hence the number of the components is large, and further the procedures for manufacturing and assembling the components are complicated, such that the space in the lighting device cannot be utilized effectively.
One object of the present invention is to provide a new type LED lighting device having reduced number of components, and a more compact structure.
Another object of the present invention is to provide a new type LED lighting device with a high bending strength.
Another object of the present invention is to provide an LED lighting device easy to implement modular production, easy to assemble.
Still another object of the present invention is to provide an LED lighting device having a low cost and easy to manufacture, which can effectively address the issue caused by mismatching of thermal expansion coefficients of different materials.
One or more of the above objects may be achieved by an LED lighting device according to the present invention. The LED lighting device includes: a housing; an LED light-emitting unit arranged inside the housing; and an LED driver, configured to drive the LED light-emitting unit to operate; wherein the LED driver and the LED light-emitting unit are integrally arranged inside the housing.
By integrating the LED driver and the LED light-emitting unit into one piece, the objects of reducing the number of components, simplifying the structure and the assembling steps and saving the space are achieved.
Preferably, the LED lighting device further includes a bracket made of steel, configured to support the LED driver and the LED light-emitting unit inside the housing, and also used to dissipate heat and improve a bending strength of the lighting device.
Preferably, the light device further includes an end cap configured to close an opening of the housing, and configured to electrically connect the LED driver and the LED light-emitting unit to an external power supply. More preferably, the end cap includes a locking part, and the end cap may be snap-fitted to the bracket by the locking part. Thus, simple assembling is achieved, and the issue of getting stuck or deformation of the plastic tube caused by mismatching of thermal expansion coefficients of different materials is addressed.
A method for manufacturing a lighting device is further provided according to the present invention, which includes the following steps: soldering electronic components of an LED driver and LED elements of an LED light-emitting unit on the same circuit board; adhesively bonding the soldered circuit board on a bracket; disposing the adhesively bonded assembly of the circuit board and the bracket into a housing from an opening of the housing; and closing the opening of the housing by an end cap.
Features and advantages of the present invention may be understood more readily from the detailed description to specific embodiments given by reference to the drawings in which, like features or components are indicated by like reference numerals, and the drawings are not necessarily drawn to scale, and in which:
Exemplary embodiments of the present invention will be described hereinafter in detail with reference to the drawings. The description of the exemplary embodiment is only for the purposes of example, and not a limitation to the present invention and the application or use thereof.
Spatially relative terms, such as “inner”, “outer”, “beneath”, “below”, “low”, “above”, “upper” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the features is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the example term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.
An LED lighting device according to the present invention will be described hereinafter with reference to
As shown in
The housing 10 is typically a lamp tube of various models, such as extruded T5, T8 tubes. Since the heat generated by an LED light source is low, instead of metals and glass materials with high heat resistance, the housing 10 according to the embodiment of the present invention for example may be a T5 plastic tube, the T5 plastic tube is extruded from a polymer material which has high light transmission, strong water resistance, is not easy broken, is easy molded, and is of aging resistance, light weight and low cost. The polymer material may be for example polycarbonate (PC), polymethyl methacrylate (PMMA), polyvinyl chloride (PVC) etc. However, the housing of the lighting device of the present invention is not limited thereto, and may be formed from any suitable materials.
As shown in
The LED element is a solid-state semiconductor light source capable of converting an electrical energy into a visible light, with the specific voltage current characteristic of the semiconductor light source, when the voltage applied on the LED element exceeds the dead zone voltage, the current changes exponentially with the voltage. Therefore, in order to allow the LED element to work normally and not to be burned out due to a slight fluctuation of the voltage, the LED lighting device 100 generally further includes an LED driver 30, which is used as a constant-current driving source for the LED element 22 to control the current flowing through the LED element, such that the current will not be higher than the rated current of the LED element and will not be affected by a difference in a forward bias voltage and in an input voltage of the LED element. The LED driver 30 is namely a component by which commercial electricity is transformed, rectified and filtered to be outputted to the LED light-emitting unit 20, and the LED driver 30 generally consists of a drive circuit 32 including multiple electronic components 31.
In the conventional technology, the LED driver is, generally electrically connected as an integral component in a form of a separate package or a circuit board to the LED circuit board of the LED light-emitting unit accommodated in the housing of the lighting device, thus an electrical connecting device is required to be provided additionally, which increases the complexity and cost of processing and assembly. Especially, in the case that the interior space of the housing of the LED lighting device is insufficient, the LED driver will be arranged outside the lighting device, for example, on a special mounting bracket or a lamp socket, and is electrically connected to the interior of the lighting device via an electric wire. Take LED tube for example, it may be classified, according its diameter and from small to large, into T2, T3, T4, T5, T8, T10 and T12 tubes, among which, T5 tube and T8 tube are most common. T8 tube has a diameter of 26 mm and thus has an interior space large enough to have an conventional LED drive directly accommodated in the tube and electrically connected to the LED circuit board. By contrast, T5 tube only has a diameter of 16 mm with limited interior space. Therefore, a T5 tube in the conventional technology often adopts an external LED driver due to its insufficient interior space, and a special mounting bracket is also provided to be used with the T5 tube, thus the manufacturing cost of the product is higher, the installation on site is more complex, and the aesthetics and safety and practicability of the product are reduced.
As shown in
Specifically, as shown in
Compared with the conventional technology in which the LED driver 30 is electrically connected as a separate component to the LED circuit board 21, integration of the LED driver 30 on the LED circuit board 21 is able to reduce the number of the separate components in the lighting device, and reduce the need for additional electrical connection between the LED driver and the LED circuit board, thus simplifying the structure and assembly of the lighting device, and reducing the number of fault points to improve the reliability of operation. Further, since the structure and assembly of the lighting device is simplified, space saving can be achieved, this is especially important for a small lighting device.
Furthermore, as shown in
Since the electronic components 31 of the LED driver 30 are divided to be arranged on the upper and lower side surfaces of the LED circuit board 21, compared with the case that these electronic components are arranged on one side of the LED circuit board, the interior space of the tube may further be effectively used, which makes it possible for a small lighting device such as T5, T4 tubes to allow the LED driver to be internally mounted, thus eliminating the need for a special mounting bracket.
In addition, as shown in
The cross section of the bracket 40 generally has an arc shape, is in conformity with a profile of the inner surface of the housing 10 and is configured to fit against the inner surface of the housing 10. According to some embodiments of the present invention, two side ends of the arc-shaped bracket 40 respectively abut two hook-shaped portions 11 which are formed integrally on the inner surface of the housing 10 to extend in a direction towards the bracket 40, to limit the slippage of the bracket 40 in a circumferential direction along the inner surface of the housing 10. The hook-shaped portions 11 may be extruded integrally with the housing 10. As shown in
As shown in
In the embodiment shown in
The shape of the bracket 40, the way of fixing the bracket 40 and the configuration of the supporting part 41 are not limited to the specific example described above, and may be implemented in different ways, and the implementations all fall into the scope of the present invention.
Reference is made to
As shown in
In addition, as shown clearly in
Each of the end caps 52 and 53 may further include a locking part 55, and the locking parts 55 may be snap-fitted on the bracket 40, thus locking the end caps 52 and 53 onto the bracket 40.
The above locking structure of the end caps 52 and 53 and the bracket 40 according to an embodiment of the present invention is further described in detail hereinafter with reference to
According to the embodiment illustrated, the locking part 55 extends a length horizontally along a longitudinal direction of the end cap 52, 53 from an insertion end of the end cap 52, 53. The locking part 55 is substantially in an L shape, and includes, at its tip end, a locking protrusion 551 protruding downward. The locking part 55 may be integrally molded with the end cap 52, 53.
Correspondingly, as shown in
With such an arrangement, when inserting the end cap 52, 53 into the housing 10 with the locking part 55 of the end cap 52, 53 being aligned with the elastic tab 42 of the bracket 40, the locking protrusion 551 at the tip end of the locking part 55 depresses the elastic tab 42 bending upward obliquely, and then passes over the elastic tab 42, till the locking protrusion 551 fully falls into the cutout 43 in the process of advancing of the end cap 52, 53, and no longer applies a sufficient urging force downward to the elastic tab 42. As shown more clearly in
In order to prevent the end cap and the bracket from integrally moving along the longitudinal direction, as shown in
Since the housing 10 of the lighting device 100, and the bracket 40, the LED circuit board 21 accommodated in the housing 10 are all in an elongated shape, and made of materials having different thermal expansion coefficients, hence the difference in heat expansion and cold contraction in the longitudinal direction of the plastic housing and those metal components inside the plastic housing is appreciable, thus being apt to cause the tube to get stuck due to dimension discrepancy caused by this difference. In the present invention, with the end cap 52 and 53 being locked to the steel bracket 40 instead of the housing, the bracket 40 and the LED circuit board 21 are allowed to extend or contract freely in the longitudinal direction, and with the arrangement of the grooves 56, the end caps 52, 53 are allowed to displace with respect to the housing 10 in the longitudinal direction appropriately, thus simply and effectively addressing the issue of getting stuck or deformation of the lighting device 100 caused by mismatching of the thermal expansion coefficients of different materials.
The LED lighting device 100 of the present invention having the above configuration is easy to manufacture and assemble, and facilitates modular production. The manufacturing method of the LED lighting device 100 according to an embodiment of the present invention is described hereinafter with reference to
As shown in
Though it is put forward herein the example of the LED tube in which the LED driver is integrated at one end of the LED circuit board, it may be appreciated by those skilled in the art that the embodiment of the present invention is not limited thereto. Instead, the LED driver may be integrated in any appropriate part(s) of the LED circuit board according to requirements. Hence, the conception of the present invention is also applicable in LED lighting devices in any other shapes and configurations, including the LED tube being applied voltage from two sides.
In addition, though the present invention is illustrated taken the T5 tube as an example, the LED lighting device in the present invention may also be formed in any other shapes, for example, circular, elliptic, and triangular, and various irregular shapes, and in some variations, the LED lighting device may have only one opening in a housing.
While preferred embodiments of the present invention have been described in detail herein, it should be understood that the present invention is not limited to the specific structures described in detail and illustrated herein, and those skilled in the art can also achieve other variants and modifications without departing from the principle and scope of the application, and these variants and modifications should also be deemed to fall into the protective scope of the present invention.
Number | Date | Country | Kind |
---|---|---|---|
2016 1 0041814 | Jan 2016 | CN | national |
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/EP2017/051182 | 1/20/2017 | WO | 00 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO2017/125545 | 7/27/2017 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
20100008085 | Ivey | Jan 2010 | A1 |
20120262921 | Boomgaarden et al. | Oct 2012 | A1 |
20130170196 | Huang | Jul 2013 | A1 |
20150267874 | Terazawa | Sep 2015 | A1 |
20170051881 | Chamberlain | Feb 2017 | A1 |
Number | Date | Country |
---|---|---|
202010013037 | Mar 2011 | DE |
102014205360 | Sep 2015 | DE |
2015179731 | Nov 2015 | WO |
Number | Date | Country | |
---|---|---|---|
20190032863 A1 | Jan 2019 | US |