Patent Application
20160091157
This application claims priority to Italian Patent Application Serial No. TO2014A000764, which was filed Sep. 26, 2014, and is incorporated herein by reference in its entirety.
Various embodiments may generally relate to lighting devices.
One or more embodiments may find an application in lighting devices employing solid state light radiation sources such as, for example, LED sources.
Linear LED modules are an example of lighting devices exhibiting modularity. Modularity in a product enables cutting the module to length at certain fixed points.
In various implementations, the cutting points and the corresponding circuit are visible to the final user from the front or top side (i.e. the side carrying the light radiation sources, e.g. the LEDs) or they may be made visible via a particular marking (e.g. ink or laser printing).
In a protected module, where no transparent materials are used, the cutting points which may be present on the device support (for example a Printed Circuit Board, PCB) may not be recognizable through a direct observation of the circuit and/or the marking. When an opaque material is used, it is impossible to identify the cutting points by observing the position of the LEDs or the associated electronics, which are not visible. This is an intrinsic limit for those applications wherein the module must be cut to length.
This problem may be countered in protected modules through a marking (e.g. a laser marking) of cutting points on one side of the module. The alignment of cutting points may be based on the position of the light radiation sources, adapted to be the only visible components.
This approach is critical due to the tolerances of the marking, to the possible shrinkage of different materials during the process and to the need, in the positioning of the module, of aligning the marking with the layout of the support (e.g. of the PCB).
These problems have been found to be virtually unsolvable if the support (e.g. the PCB) and/or the components are not visible to the final user, so that the module may be cut but, for example, without offering the possibility to reconnect a part of the module.
Various embodiments aim at overcoming the previously outlined drawbacks.
According to various embodiments, said object is achieved thanks to a lighting device having the features specifically set forth in the claims that follow.
Various embodiments may also concern a corresponding method.
In various embodiments it becomes possible to obtain a lighting module, e.g. a LED lighting module, adapted to be cut in different points without the need of seeing the module top side.
Various embodiments may achieve one or more of the following advantages:
In the drawings, like reference characters generally refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention. In the following description, various embodiments of the invention are described with reference to the following drawings, in which:
In the following description, numerous specific details are given to provide a thorough understanding of one or more exemplary embodiments. The embodiments may be practiced without one or several specific details, or with other methods, components, materials, etc. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring various aspects of the embodiments. Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the possible appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, particular features, structures, or characteristics may be combined in a suitable manner in one or more embodiments, and/or may be associated to the embodiments in a different way from what is shown herein, so that e.g. a feature herein exemplified in connection to a Figure may be applied to one or more embodiments exemplified in a different Figure.
The headings provided herein are for convenience only, and therefore do not interpret the scope or meaning of the embodiments.
In the Figures, reference 10 denotes on the whole a solid state lighting device.
This lighting device may consist, in various embodiments, of a so-called LED module, including electrically powered light radiation sources 12, e.g. LED light radiation sources, arranged on an elongated support member 14.
As far as the present description is concerned, device 10 may be considered as including a (optionally flexible) bar or strip of a generally undefined length. In various embodiments the need is present to cut such a module 10 to length, at cutting positions which are identified with sufficient precision, so as to obtain a lighting device of a desired length.
Support member 14 may have different shapes, according to the adopted implementation.
For example, support member 14 may include an elongated support element 16, e.g. a Printed Circuit Board (PCB).
In various embodiments, on the basis of the application and design requirements (power supply currents, features of electronic circuits, thermal characteristics), support board 16 may include various layers of a conductive material, e.g. copper.
In various embodiments, there may be provided a single layer PCB 16, having one single layer of conductive material applied on the base material, e.g. by using a special adhesive.
The exposed side of the conductive layer may require covering via a covering layer 18, adapted to prevent the conductive metal layer (e.g. copper) from oxidizing.
In various embodiments, there may be provided a double layer PCB 16, having two layers of conductive material (e.g. copper) applied on the opposing sides of a base material layer. In this case, too, there may be provided a covering layer 18, e.g. having a protection function of the electrically conductive layers.
In this regard it may moreover be observed that, in lighting (e.g. LED) modules as exemplified herein, the light radiation sources and the components associated thereto may be mounted on the top or front side of module 10, while the bottom (or back) side is not used for mounting components and is coated by a cover layer 18 to ensure electrical isolation.
In various embodiments, the covering layer may be made of different materials, such as resins as polyimmide (PI), polyethylene terephthalate (PET), polyethylene naphthalate (PEN).
When there is no need to provide an electrical insulation, the covering layer may consist of a finishing material (Organic Solderability Preservative (OSP), silver, gold, etc.).
In various embodiments, such a covering layer 18 may also include or consist of a solder mask.
Whatever the specific implementation details, in such a modular device 10 both the light radiation sources (e.g. LEDs 12 shown in
In various embodiments, as schematically shown in
This may take place also if on the bottom (or back) side of module 10 there is applied a further layer 22 of a light permeable (transparent) material, adapted to seal device 10 while imparting protection features against the penetration of foreign agents (IP protection).
In various embodiments discontinuities 20, which are regularly spaced along the lengthwise extension of device 10, may create a marking scale for cutting to length modular lighting device 10.
In this way, discontinuities 20 may act as markers for the cutting operation, being arranged according to a regular pattern, e.g. as openings in covering layer 18 (whatever the latter may be: a cover layer, a solder mask, etc.).
Thanks to their regular distribution, discontinuities 20 may therefore act as an array of markers, which are located at particular positions along the lengthwise extension of module 10 (axis X10 in
It will be appreciated, moreover, that the solution according to various embodiments can be applied also in those cases wherein (unlike the previously described examples) the observation of the front side or of the lateral sides of module 10 might in itself enable spotting the position of components within module 10.
Various embodiments enable the alignment of a laser marking with respect to the layout of board 16 (e.g. in order to identify the positions of light radiation sources 12). This operation may be performed e.g. on an edge of a protected module 10 where an opaque material is present on the front side, so as to mask all components, including LEDs, while a transparent material 22 is applied on the bottom or back side of module 10, in order to provide the latter with an IP (Ingress Protection).
It will be appreciated that various embodiments enable to keep a high level of accuracy in the production and in the identification of circuits by final users. This applies e.g. to the position of light radiation sources 12: the marking layout given by discontinuities 20 in covering layer may actually correspond to the circuit layout, adapted to be implemented with a higher accuracy than is the case with the positioning of components on the circuit itself, which may be affected by size, positioning and assembling tolerances.
In various embodiments, a laser marking may be controlled by a camera observing the back side of module 10.
This advantage may be appreciated also during production, as discontinuities 20 in cover layer 18 may correspond to openings for accessing electrical connection pads for the module components. This may e.g. simplify testing operations, giving the possibility to extend testing operation to an access on both front and back side of module 10.
While the disclosed embodiments have been particularly shown and described with reference to specific embodiments, it should be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the disclosed embodiments as defined by the appended claims. The scope of the disclosed embodiments is thus indicated by the appended claims and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced.
| Number | Date | Country | Kind |
|---|---|---|---|
| TO2014A000764 | Sep 2014 | IT | national |
