Patent Description:
Considering a circular economy and a demand for serviceability, the lighting industry moves increasingly towards lighting modules which are easily replaceable and/or exchangeable in the field. These lighting modules may often comprise a Printed Circuit Board (PCB) with a plurality of semiconductor light sources (e.g. a CEM1 board with LED light sources). See e.g. <CIT> disclosing a light bar structure including a substrate, an electrical unit, and light-emitting diodes. The electrical unit includes a light-source disposing portion, at least one flexible connector, and at least one electrical connection end. The flexible connector connects on one end to the light-source disposing portion and on the other end to the electrical connection end. A further lighting module of the prior art is disclosed in <CIT>.

Such lighting modules may for example be fitted into e.g. a luminaire or a troffer. Such a lighting module may however be impractical or disadvantageous for line-lighting applications - wherein the concept of line-lighting is commonly accepted in the field as a linear lighting application providing a continuous and/or uninterrupted line of light - because such a lighting module often comprises a connector for powering said module which interrupts said line of light and/or margins said line of light (at the edge of the module).

For example, considering an elongated lighting module comprising a Printed Circuit Board with a connector disposed at one end: Placing this lighting module into e.g. a troffer will render a dark vignette at the edge of the lighting module, hence margining the line of light and giving an inconvenient and inefficient line-lighting experience; Placing a plurality of such lighting modules back to back into e.g. troffer will render a plurality of undesired interruptions in the line of light, hence also giving an inconvenient and inefficient line-lighting experience. This is especially disadvantageous in LED line-lighting applications, for example if the area required for the connector is bigger than the pitch between the LED light sources.

It is an object of the invention to provide an improved lighting module, which at least alleviates the problems mentioned above; e.g. providing an improved and/or cost-reduced lighting module for line lighting applications without having undesired interruptions in the line of light. Thereto, the invention provides a lighting module comprising an elongated carrier and a flexible circuit; wherein the flexible circuit comprises a first section accommodating a plurality of LED light sources, a second section, and a connector; wherein the connector is accommodated in the second section for receiving power to power said plurality of LED light sources and extends at least partly in the first section; wherein the elongated carrier comprises first end-face and a second end-face, and extending therebetween comprises a first elongated main surface and a second elongated main surface, the second elongated main surface being opposite to said first elongated main surface; wherein the first section of the flexible circuit is connected to said first elongated main surface, and wherein the second section of the flexible circuit is connected to said second elongated main surface; wherein the elongated carrier comprises at least one rim arranged on the first elongated main surface, wherein the at least one rim extends continuously between the first end-face and the second end-face; wherein the at least one rim is a lightguide.

Such a lighting module comprises an elongated carrier comprising a first end-face, a second end-face and extending therebetween a first elongated main surface and a second elongated main surface. The second elongated main surface and the first elongated main surface are opposite to each other. Such a lighting module also comprises a flexible circuit. More specifically, the flexible circuit may also be defined as a flexible Printed Circuit Board; a circuit foil or film; or a flexible electronic(s). The flexible circuit comprises a first section accommodating a plurality of LED light sources, which first section is connected to said first elongated main surface. The flexible circuit also comprises a second section accommodating a connector for receiving power to power said plurality of LED light sources, which second section is connected to said second elongated main surface. More specifically, the connector may also be defined as an electrode; a terminal; or a track or an electronic track. Moreover, said LED light source may be any other semiconductor light source, such as e.g. OLED. Said light sources may radiate outwards away from the flexible circuit and/or essentially away from the elongated carrier, and may alternative comprise optics therefor.

Moreover, said elongated carrier may also be defined as an elongated substrate, or elongated strip. The elongated carrier may be defined as elongated (essentially/substantially) extending in an axial (length) direction. Hereby, the elongated carrier may be extending in an axial direction, but be comprising a curvature in axial direction. Some luminaire design examples comprise such a slightly bent form.

Therefore, by this very configuration, a plurality of LED light sources will be present at the first elongated main surface of the elongated carrier for providing line-lighting continuously between the first end-face and second end-face, whereas said connector (arranged for powering said LED light sources) will be present at the second elongated main surface of the elongated carrier and thereby not interrupting the line-lighting provided by said LED light sources. Hence, the present invention may provide an advantageous and improved lighting module for line-lighting applications.

The improved configuration of the lighting module according to the invention is furthermore advantageous in terms of cost-reduction. The lighting module is namely enabled by the described implementation of the flexible circuit. The flexible circuit may hereby, in embodiments, be connected to a more rigid carrier (Flex-on-Rigid) to ensure that the lighting module obtains a form, a fit and/or a function similar to regular PCB technology, such as e.g. CEM1 or FR4 based PCB's. The advantage of using such a Flex-on-Rigid configuration is that costs are significantly reduced: i.e. a flexible PCB (flexible circuit) is generally about <NUM> USD cents per <NUM> (<NUM> feet), whereas a CEM1 PCB is generally about <NUM> USD cents per <NUM> (<NUM> feet).

Thus, the lighting module according to the invention may have a clear cost advantage over lighting modules making use of said regular PCB technology to solve said above problems (e.g. by alternative placement of components to provide a continuous line of light).

More cost reduction may further be achieved. As partly mentioned before: The first section of the flexible circuit is connected to said first elongated main surface, and the second section of the flexible circuit is connected to said second elongated main surface. The connector is accommodated in the second section for receiving power to power said plurality of LED light sources. The connector also extends at least partly in the first section. As a result of this, the manufacturing of the lighting module is facilitated, and manufacturing costs are less. Namely: A particular configuration of the flexible circuit may be used for a plurality of length sizes of the elongated carrier, because the connector extends at least partly into the first section. Hence, no dedicated flexible circuit may be required for a plurality of elongated carriers, but a single or a standardized flexible circuit may be used for each of said plurality of elongated carriers. Moreover, less precision is required in cutting a flexible circuit strip so as to obtain the flexible circuit, which is connected to the first elongated main surface and second elongated main surface respectively. Furthermore, the connecting of the first section of said flexible circuit to said first elongated main surface and the connecting of the second section of the flexible circuit to said second elongated main surface, so as to position the connector accordingly at least at the second section, is less meticulous due to the possibility for the connector to extend at least partly in the first section.

For example, the connector may comprise a track disposed on the flexible circuit, which track may be extending into the first section and running along the LED light sources. This may significantly reduce costs of manufacturing the lighting module according to the invention.

In an embodiment, the connector may extend completely in the first section. Thus, in such cases, the connector may cover the completely a length of the first section. In another embodiment, the connector may extend at least partly in the first section, wherein the connector extends to a halve, a quarter, or one-eighth of a length of the first section.

Consequently, as partly mentioned, an improved lighting module is established. For example: Since the connector of the lighting module is located at a surface opposite to the surface having the plurality of LED light sources, the module may easily be fitted and/or mounted to e.g. a luminaire or a troffer via the surface having the connector, while still keeping an uninterrupted continuous line of light via the surface having the LED light sources. As the flexible circuit facilitating such a configuration is moreover cost-effective, the proposed lighting module may be advantageous in the field of lighting, which field of lighting moves towards easily replaceable and exchangeable line-lighting applications in the field.

As mentioned, the elongated carrier comprises at least one rim arranged on the first elongated main surface, wherein the at least one rim extends continuously between the first end-face and the second end-face. By introducing said at least one rim to the elongated carrier, which provides more mass away from a center of the cross-sectional profile of the elongated carrier, more bending stiffness may be obtained. Said at least one rim may e.g. be two rims, each extending on either elongated edge of the first surface. The at least one rim serves as a lightguide.

In an embodiment, the flexible circuit may be folded around the second end-face or the first end-face. Thus, the flexible circuit comprises a fold being folded around the second end-face or the first end-face. (Thus, the lighting module comprises either a first or second an end-face around which the flexible circuit may be folded). Such a lighting module is advantageous, as the flexible circuit may be connected to said first elongated main surface, easily folded over the first end-face or the second end-face, and subsequently be connected to said second elongated main surface. Such a fold is enabled by the flexibility of the flexible circuit, which means that the flexible circuit may for example be manufactured in one piece, but able to be connected or draped upon opposite surfaces.

A flexible circuit accommodating a plurality of LED light sources with a particular pitch in between said LED light sources may e.g. be supplied as a starting material for manufacturing said lighting module. A connector, or a track being the connector, may run along the plurality of LED light sources. The flexible circuit may subsequently be cut to a particular size to form the lighting module according to the invention. Said cut may be in between two consecutive LED light sources, i.e. in between the pitch. Subsequently, when connecting said flexible circuit to the elongated carrier: The first section of the flexible circuit is connected to said first elongated main surface, and the second section of the flexible circuit is connected to said second elongated main surface; wherein the flexible circuit may be folded around the second end-face or the first end-face. Thus, the flexible circuit comprises a fold being folded around the second end-face or the first end-face. The second section is therefore formed after the bend of the flexible circuit, which part before the bend remains or may be the first section accommodating the plurality of LED light sources. Thus, the flexible circuit comprises a first section, wherein the first section may be bend at any location form after the bend a second section accommodating the connector.

In further embodiments, the flexible circuit may be folded around the second end-face or the first end-face by means of a fold, wherein the fold is located at an interface between the first section of the flexible circuit and the second section of the flexible circuit. Such a fold at the interface between said first section and said second section may be preferred, since it constitutes a clear boundary between the connector and its connecting function and the plurality of LED light sources and its line-lighting function. Alternatively, the flexible circuit may be folded around the second end-face or the first end-face by means of a fold, wherein the fold is located within (or at) the first section of the flexible circuit. In this situation, it is ensured that the second section accommodating the connector is fully located on the second elongated main surface.

Yet alternatively, in some embodiments, it may be preferred that the lighting module comprises more than one connector, for example a connector on either edge of the elongated lighting module, such that the lighting module may be connected on either edge to facilitate a more versatile application, mounting, etc. Thus, a second connector; or a 'further' connector. Hence, in such a situation, the connector according to the invention may be phrased as the first connector. Thereto, in some embodiments, the flexible circuit may comprise a third section accommodating a second (or: further) connector for receiving power to power said plurality of LED light sources; wherein said first section of the flexible circuit is located between said second section and said third section of the flexible circuit; wherein the third section of the flexible circuit may be connected to said second elongated main surface. Thus, in even a further embodiment related thereto, the flexible circuit may be folded around the second end-face and the first end-face. Both connectors may be arranged to receive power to power said plurality of LED light sources, whereas only one of those or both may be powering the LED light sources when in operation. Hereby, a lighting module is established which is capable of being connected to receive power via either the first connector, the second connector, or both. Mounting and operability is hence facilitated. Moreover, whenever a first connector fails within e.g. a troffer, the lighting module may easily be detached from the troffer, rotated, and mounted again in the troffer with the second connector performing the function of the failed first connector.

In further embodiments, the flexible circuit may be folded around the second end-face and the first end-face by means of a first fold and a second (or: further) fold, wherein the first fold is located at an interface between the first section of the flexible circuit and respectively the second section of the flexible circuit, wherein the second (or: further) fold is located at an interface between the first section of the flexible circuit and respectively the third section of the flexible circuit. Such a first fold and second (or: further) fold at the interface between said first section and respectively said second section and said third section may be preferred, since it constitutes a clear boundary between the connector and its connecting function and the plurality of LED light sources and its line-lighting function. Alternatively, said first fold and said second (or: further) fold may be located within (or at) the first section of the flexible circuit. This again ensures that the sections accommodating the connector are fully on the second elongated main surface.

In an embodiment, the first end-face and/or the second end-face comprises a recess for folding around the flexible circuit. Thus, the flexible circuit is folded around the recess. Thus, as mentioned, the first end-face and/or the second end-face may comprise a recess around which the flexible circuit is folded. Such an embodiment is advantageous, because the recess may protect a fold created by folding around the flexible circuit around said respective first end-face or second end-face. This is especially advantageous whenever the lighting modules are positioned back to back in e.g. a luminaire or troffer. Namely: The present invention advantageously enables to create a continuous line of light with the lighting modules, which may for example be established by tightly fitting a lighting module in e.g. a troffer or a luminaire, or by tightly fitting a plurality of lighting modules back to back to each other in e.g. a troffer or a luminaire. However, this may expose any of said fold(s) around the respective end-faces to friction when mounting. As said friction may result in possible wear of the flexible circuit, the recess of the present embodiment is advantageously preventing such a situation.

Said recess may be an incurvature or may be stepped. In embodiments, a depth of said recess may be at least equal to a thickness of the flexible circuit; or may be at most equal to twice the thickness of the flexible circuit. Such an embodiment is advantageous, as a clear balance is found between the depth required to protect the fold of the flexible circuit and the requirement to create a recess in the elongated carrier.

In an embodiment, the elongated carrier may be made of a material being one of: a metal, a ceramic, a polymer, or a combination thereof. The elongated carrier may for example be made of copper, aluminum, or steel; or Polypropylene (PP), Polyethylene terephthalate (PET), polyethylene (PE); or fiber reinforced polymer, such as e.g. carbon fiber or glass fiber.

In an embodiment, the elongated carrier may comprise a length, the length being defined as the shortest distance between the first end-face and the second end-face, the length being at least <NUM> centimeters. Yet alternatively, said length may be at least <NUM> centimeters, or at least <NUM> centimeters, such as e.g. <NUM> centimeters. Such a length may be a standard length for specific types of troffers or luminaires. Such a length may also be defined by industry standards or market preferences.

For example, said length may at least be <NUM> millimeters. Said length may also at least e.g. be <NUM> millimeters; <NUM> millimeters; <NUM> millimeters; <NUM> millimeters. Said length may for example be such that only one lighting module is required over the length of one lighting device and/or luminaire.

In an embodiment, the first section of the flexible circuit may comprise at least thirty successively arranged LED light sources. For example, said first section of the flexible circuit may comprise at least <NUM> successively arranged LED light sources, or at least <NUM> successively arranged LED light sources, or at least <NUM> successively arranged LED light sources, or at least <NUM> successively arranged LED light sources. Such LED light sources may be arranged on the flexible circuit in a matrix, wherein the matrix may for example comprise a single (linear) column / line; two columns/ lines; or three columns / lines. Said LED light sources may be RGB colored or white; and may provide a full spectrum of color. More LED light sources means more pixels and higher resolution of the line-lighting application. The amount of LED light sources being successively arranged may also be defined by industry standards or market preferences. A maximum pitch between successively arranged LED light sources may be at most <NUM> millimeters.

It may be advantageous for line-lighting applications to have a lighting module which comprises a limited width. Such a width may be defined by the amount of LED light sources implemented and the configuration of the array of LED light sources disposed on the flexible circuit. Hence, in an embodiment, the elongated carrier comprises a width, the width being defined as the shortest distance of the first elongated main surface perpendicular to said length of the elongated carrier, the width being at most four centimeters. In some embodiments, the width being at most three centimeters. In some embodiments, the width being at most five centimeters, e.g. for bigger modules, e.g. in false ceiling applications. Alternatively, the width may be at most two centimeters, or at most one centimeter. Said width may also be defined by industry standards or market preferences. Furthermore, a minimum width may be at least three millimeters, or at least the width of a LED light source. Such a minimum width may alternatively be at least <NUM> millimeters, as modules may e.g. be <NUM>-<NUM> millimeters in width.

In an embodiment, the elongated carrier may be plate-shaped. Such a shape may be manufactured more easily and may comprise a standard shape. Further, in examples, said elongated carrier may be a I-shaped elongated profile, a H-shaped elongated profile, a L-shaped elongated profile, a U-shaped elongated profile, etc. The elongated carrier may for example be extruded. Alternatively, said lighting module, including said flexible circuit, may for example be partly manufactured by extrusion.

As mentioned before, the proposed lighting module may be advantageous in the field of lighting, especially in line-lighting applications, which field of lighting moves towards easily replaceable and exchangeable line-lighting applications in the field. Replacement of lighting modules comprising an elongated shape may be cumbersome whenever the lighting module deflects under its own weight. Therefore, it may be advantageous that a lighting module comprises sufficient bending stiffness.

Hence, in an embodiment, the elongated carrier may comprise a cross-section comprising a curvature for improving the bending stiffness of the lighting module and for thereby reducing a deflection of the lighting module in its elongated direction. Said bending stiffness may be defined as the height which one end of the elongated carrier may deflect when having the other end fully constrained in its degrees of freedom. In some examples, therefore, the elongated carrier may comprise a bending stiffness, wherein the bending stiffness is defined as the deflection of the second end-face when the first end-face is fully constrained in all its degrees of freedom, wherein said deflection of the second end-face in respect to the first end-face is not greater than <NUM> centimeters (under its own weight, without any other external forces). In some examples, said deflection may not be greater than <NUM> centimeters (under its own weight, without any other external forces).

Said curvature may be a circular curvature with a radius of curvature. Said curvature may for example span an angle between <NUM> degrees and <NUM> degrees, or span at most <NUM> degrees; or span an angle between <NUM> degrees and <NUM> degrees.

As mentioned, said bending stiffness may be obtained by introducing rims to the elongated carrier, which provide more mass away from a center of the cross-sectional profile of the elongated carrier. Thus, according to the claimed invention, the elongated carrier comprises at least one rim arranged on the first elongated main surface, wherein the at least one rim extends continuously between the first end-face and the second end-face. The rims additionally serve as lightguide.

Said at least one rim may e.g. be two rims, each extending on either elongated edge of the first surface. Said at least one rim may e.g. be four rims. For example, said four rims may be formed by two pairs of rims, wherein one couple of rims extends on a first elongated edge of the first surface and the second couple of rims extends on a second elongated edge of the first surface. Thereby, a respective groove may be formed in-between each of said pair of rims, which groove may advantageously comprise / or be used for: connecting means for e.g. optics, or mounting means for mounting the light module, or (serve as) a lightguide, a reflector, or a mixing wall.

Alternatively, in other aspects, not being part of the claimed invention, said cost of the lighting module may be reduced even further by having the elongated carrier be part of the flexible circuit. In such embodiments, the flexible circuit may comprise the elongated carrier, wherein a cross-section of the elongated carrier may comprise a curvature for improving the stiffness of the lighting module and for thereby reducing a deflection of the lighting module in its elongated direction. The elongated carrier may therefore be a flexible layer for reinforcing the flexible circuit, such as a reinforcing metal layer, adhesive layer, or polymer layer. The elongated carrier may also be flexible strip, such as a polymer strip or a metal strip. Said cross-section may be the cross-sectional profile of the elongated carrier, hence the profile of the elongated carrier in connection - e.g. in assembly - with the flexible circuit. Said cross-section may thus be the plane perpendicular to the longitudinal axis of the elongated carrier, i.e. the plane perpendicular to the line extending between the first end-face and the second end-face.

As mentioned before, mutatis mutandis, said bending stiffness may be defined as the height one end of the elongated carrier may deflect when having the other end fully constrained in its degrees of freedom. In some examples, therefore, the elongated carrier may comprise a bending stiffness, wherein the bending stiffness is defined as the deflection of the second end-face when the first end-face is fully constrained in all its degrees of freedom, wherein said deflection of the second end-face in respect to the first end-face is not greater than <NUM> centimeters (under its own weight). In some examples, said deflection may not be greater than <NUM> centimeters (under its own weight). Said curvature may be a circular curvature with a radius of curvature. Said circular curvature may for example span an angle between <NUM> degrees and <NUM> degrees, or span at most <NUM> degrees; or span an angle between <NUM> degrees and <NUM> degrees. Alternatively, at higher radius of curvature, e.g. above <NUM> centimeters, said curvature may for example span at most <NUM> degrees, or preferably span at most <NUM> degrees; or preferably span at most <NUM> degrees.

In an embodiment, the flexible circuit is folded around the first end-face and the elongated carrier is plate-shaped; wherein the elongated carrier comprises a length, the length being defined as the shortest distance between the first end-face and the second end-face, the length being at least <NUM> centimeters; wherein the first section of the flexible circuit comprises at least fifty successively arranged LED light sources; wherein the elongated carrier comprises a width, the width being defined as the shortest distance of the first elongated main surface perpendicular to said length of the elongated carrier, the width being at most four centimeters. Such a configuration of the lighting module may become an industry standard, hence advantageously reducing manufacturing costs.

In all embodiments, the connector (either the first, or the second, or both, or any more connectors) and the plurality of LED light sources may be arranged consecutively on the flexible circuit. Said components may form a single line on the flexible circuit along the elongated direction of the lighting module. Hence, the flexible circuit may be a strip, which may e.g. be a straight strip without branches. Moreover, the connector(s) may not only be arranged for receiving power to power said plurality of LED light sources, but may also be arranged - in respect to the plurality of LED light sources or other components on the flexible circuit - for data communication, for data exchange, for providing control commands, for outputting diagnostics signals, or for mechanical fixture.

Moreover, the flexible circuit may comprise itself a plurality of layers, wherein the circuit may be disposed therein. One of such layers may be the elongated carrier, usually the bottom layer.

The flexible circuit may have a thickness of at most <NUM> millimeters, or at most <NUM> millimeter, preferably at most <NUM> millimeter, or preferably at most <NUM> millimeter. Alternatively, said thickness may be at most <NUM> millimeters. The LED light sources accommodated on the flexible substrate may protrude therefrom.

As mentioned, an improved lighting module is established, which may for example be more easily mounted in a lighting device such as e.g. a luminaire or a troffer. As a result, since the connector of the lighting module is located at the second elongated main surface opposite to the first elongated main surface having the plurality of LED light sources, the module may easily be fitted and/or mounted via said second elongated main surface having the connector, while still keeping an uninterrupted continuous line of light via the first elongated main surface having the plurality of LED light sources.

Thus, it is a further object of the invention to provide an improved lighting device, which at least alleviates the problems and disadvantages mentioned above. Thereto, the invention further provides a lighting device comprising at least one lighting module according to the invention and at least one connecting unit comprising a connecting area; wherein each connecting unit is configured to electrically connect a respective connector of the at least one lighting module with the connecting area.

Said connecting unit may be designed to receive the lighting module and/or the connector according to the invention. Hence, said connecting unit may be arranged, via said connecting area, to receive and connect to an electrode, an electronic track, the circuit, or a terminal on the flexible circuit. The connecting unit may, via the connecting area, itself have a matching connector, track, pins, terminals, etc. accordingly. The connecting area may e.g. be a connecting unit connector, an electrode, an electronic track; or for example whenever the connecting area serves as a female connector, the connector according to the invention may serve as a male connector, or vice versa. These means may be known in the art of electrical connection means to a person skilled in the art.

Thus, the lighting device may either accommodate one lighting module or a plurality of lighting modules. When having a plurality of lighting modules, the lighting modules may be arranged back to back. Each module may then e.g. have its own respective connecting unit.

Alternatively, lighting modules may share one connecting unit, for example when the connection area may be arranged for receiving e.g. two lighting modules (and their respective connectors). Hence, in an embodiment, the at least one connecting unit is configured to electrically connect the connector of a respective first lighting module and the connector of a respective second (or: further) lighting module with the connecting area. This may be advantageous in mounting the lighting modules in the lighting device, as less connecting units are required.

In an embodiment, the connecting unit comprises a slot for receiving and/or detachably fixating the at least one lighting module. Consequently, the lighting modules may be easily attached and/or detached to/from the lighting device, which facilitates the replaceability or serviceability of the lighting device.

In an embodiment, the lighting device further comprises a lighting driver for providing power, wherein each connecting unit is arranged to receive power from said lighting driver and relay said power to the at least one lighting module.

Furthermore, in an embodiment, the first end-face of a first respective lighting module abuts with the second end-face of a second respective lighting module. It may namely be advantageous to position the lighting modules back to back in the lighting device, as the present invention secures a continuous line of light.

Said invention may also be implemented in troffer-based lighting devices. Hence, in an embodiment, the lighting device further comprises a troffer accommodating the at least one lighting module and the at least one connecting unit.

The advantages and/or embodiments applying to the lighting module according to the invention may also apply mutatis mutandis to the present lighting device according to the invention.

Furthermore, an improved method of manufacturing a lighting module, not being part of the claimed invention, which at least alleviates the problems and disadvantages mentioned above is disclosed.

Thereto, a method of manufacturing a lighting module comprising a flexible circuit and an elongated carrier is provided, wherein the elongated carrier comprises first end-face and a second end-face, and extending therebetween comprises a first elongated main surface and a second elongated main surface, the second elongated main surface being opposite to said first elongated main surface, wherein the method comprising: connecting a first section of a flexible circuit to the first elongated main surface of the elongated carrier, wherein the first section accommodates a plurality of LED light sources; folding the flexible circuit around the second end-face of the elongated carrier; connecting a second section of the flexible circuit to the second elongated main surface of the elongated carrier, wherein the second section accommodates a connector for receiving power to power said plurality of LED light sources and for providing control commands to the plurality of LED light sources (<NUM>, <NUM>), wherein the connector extends at least partly in the first section.

The advantages and/or embodiments applying to the lighting module and/or the lighting device according to the invention may also apply mutatis mutandis to the present method.

It is a further object of the invention to provide an improved method of electrically connecting a lighting module, which at least alleviates the problems and disadvantages mentioned above. Thereto, the invention further provides, a method of electrically connecting a lighting module according to the invention with a connecting unit comprising a connecting area and a slot, the method comprising: receiving and/or detachably fixating the connector of the lighting module in said slot; electrically connecting the connector of the lighting module with the connecting area of the connecting unit.

The advantages and/or embodiments applying to the lighting module and/or the lighting device according to the invention may also apply mutatis mutandis to the present method according to the invention.

In aspects, not being part of the claimed invention, there may be provided a lighting module comprising an elongated carrier and a flexible circuit; wherein the flexible circuit comprises a first section accommodating a plurality of LED light sources and a second section accommodating a connector for receiving power to power said plurality of LED light sources; wherein the elongated carrier comprises first end-face and a second end-face, and extending therebetween comprises a first elongated main surface and a third elongated main surface, the third elongated main surface being perpendicular to said first elongated main surface; wherein the first section of the flexible circuit is connected to said first elongated main surface, and wherein the second section of the flexible circuit is connected to said third elongated main surface.

The second section accommodating the connector may in this aspect therefore be a branch of the flexible circuit, which is connected to the third elongated main surface (a side surface, hence having the connector on the 'side' instead of on the 'back'). This may be advantageous for lighting devices, into which the lighting module is fitted, which only have a connecting unit matching to the third elongated main surface of the lighting module or differently phrased 'side'.

The advantages and/or embodiments applying to the lighting module according to the invention may also apply mutatis mutandis to the present lighting module according to the further aspects of the invention.

In aspects of the invention, there is provided: A lighting module comprising an elongated carrier and a flexible circuit; wherein the flexible circuit comprises a first section accommodating a plurality of LED light sources and, a second section accommodating a connector for receiving power to power said plurality of LED light sources; wherein the elongated carrier comprises first end-face and a second end-face, and extending therebetween comprises a first elongated main surface and a second elongated main surface, the second elongated main surface being opposite to said first elongated main surface; wherein the first section of the flexible circuit is connected to said first elongated main surface, and wherein the second section of the flexible circuit is connected to said second elongated main surface.

The invention will now be further elucidated by means of the schematic non-limiting drawings:.

As mentioned, the present invention provides an improved and/or cost reduced lighting module for line-lighting applications. Such a module does not have undesired interruptions in the line of light, because the connector of the lighting module is located at a surface opposite to the surface having the plurality of LED light sources. Therefore, the module may easily be fitted and/or mounted to e.g. a luminaire or a troffer via the surface having the connector, while still keeping an uninterrupted continuous line of light via the surface having the LED light sources.

<FIG> depicts schematically, by non-limiting example, an embodiment of a lighting module <NUM> comprising an elongated carrier <NUM> and a flexible circuit <NUM>. <FIG> depicts schematically a side-view of said embodiment depicted in <FIG>.

The lighting module <NUM> comprises an elongated carrier <NUM> comprising a first end-face <NUM> and a second end-face <NUM>. Extending between the first end-face <NUM> and the second end-face <NUM> are a first elongated main surface <NUM> and a second elongated main surface <NUM>. Here, the elongated carrier <NUM> is plate-shaped, but may alternatively comprise another cross-section, such as e.g. I-shaped, H-shaped, L-shaped, U-shaped, etc. Furthermore, the second elongated main surface <NUM> and the first elongated main surface <NUM> are opposite to each other.

Here, the elongated carrier <NUM> is made of aluminum. Alternatively, the elongated carrier may be made of any other metal, a ceramic, a polymer, or a combination thereof. The dimensions of the elongated carrier <NUM> are chosen such that it may serve as a standard module in industry. The length of the elongated carrier <NUM>, which length is being defined as the shortest distance between the first end-face <NUM> and the second end-face <NUM>, is <NUM> centimeters (for convenience, not the complete length is depicted in the figures). Thus, the length corresponds to a 2ft LED module. Alternatively, said length may be at least <NUM> centimeters, at least <NUM> centimeters, at least <NUM> centimeters, or for example <NUM> centimeters. Here, the height of the elongated carrier <NUM> is <NUM> millimeter. In examples, said height may be between <NUM> millimeter and <NUM> millimeters. The width of the elongated carrier <NUM>, which is defined as the shortest distance of the first elongated main surface <NUM> perpendicular to the length of the elongated carrier <NUM>, is <NUM>,<NUM> centimeters. Alternatively, the width of the elongated carrier may for example be at most <NUM> centimeters, or at most <NUM> centimeters.

Due to these dimensions and choice of material, the elongated carrier <NUM> is sufficiently rigid / stiff. As mentioned before, the proposed lighting module <NUM> may be advantageous in the field of lighting, especially in line-lighting applications, which field of lighting moves towards easily replaceable and exchangeable line-lighting applications in the field. Replacement of lighting modules comprising an elongated shape may be cumbersome whenever the lighting module deflects under its own weight. Therefore, it may be advantageous that a lighting module comprises sufficient bending stiffness, as demonstrated here. The bending stiffness of the elongated carrier <NUM>, which is defined as the height the second end-face <NUM> deflects when the first end-face <NUM> is fully constrained in all its degrees of freedom. Here, said deflection is not greater than <NUM> centimeters. Said deflection may be reduced by alternatively introducing a curvature in the cross-sectional profile of the plate-shaped elongated carrier, for example a curvature of <NUM> degrees.

Yet alternatively, not-depicted, said bending stiffness may be obtained by introducing rims to the elongated carrier. Thus, according to the claimed invention, the carrier comprises at least one rim arranged on the first elongated main surface, wherein the at least one rim extends continuously between the first end-face and the second end-face. The rims additionally serve as lightguide.

Referring to <FIG>, the flexible circuit <NUM> is one single-piece elongated flexible strip which comprises electronic tracks, and has a first section <NUM> and a second section <NUM>. The flexible circuit comprises a thickness of <NUM> millimeter. The first section <NUM> of the flexible circuit <NUM> accommodates a plurality of LED light sources <NUM>, which alternatively may any other semiconductor lighting device. Alternatively, other electronic components or circuit features may be present. The light sources radiate outwards away from flexible circuit. As the elongated carrier <NUM> is <NUM> centimeters, the flexible circuit <NUM> may accommodate for example <NUM> successively arranged LED light sources <NUM> with a pitch therebetween of approximately <NUM> centimeter, which are arranged in a single line along the tracks of the circuitry of the flexible substrate <NUM>. Alternatively, two or three lines of LED's may be placed next to each other, e.g. such as respectively a 2x56 or 3x56 matrix along the length of the lighting module.

Still referring to <FIG>, the flexible circuit <NUM> comprises a first section <NUM> accommodating a plurality of LED light sources <NUM> and a second section <NUM> accommodating a connector <NUM> for receiving power to power said plurality of LED light sources <NUM>. The connector <NUM> is an electrode embedded in the circuitry of the flexible circuit <NUM>; or a plurality of electrodes, such as two or three electrodes, common to powering electronics. The connector <NUM> extends at least partly in the first section <NUM>. To be more specific, the flexible circuit comprises electrodes throughout over the complete length of the elongated carrier <NUM> so as to be able to connect to a power at any location source whenever connected to a connecting unit. Hence, the connector <NUM> extends fully, i.e. <NUM>% in the first section <NUM>. Alternatively, said extending may e.g. be <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>% in the first section. Alternative connector configurations may also be possible, such as e.g. electronic tracks or pins, etc..

The first section <NUM> of the flexible circuit <NUM> is connected to said first elongated main surface <NUM>. The second section <NUM> is connected to said second elongated main surface <NUM>. Said connection may e.g. be by adhesive or other alternative conventional types of bonding. Therefore, by this very configuration, a plurality of LED light sources <NUM> will be present at the first elongated main surface <NUM> of the elongated carrier <NUM> for providing line-lighting continuously between the first end-face <NUM> and second end-face <NUM>, whereas said connector (arranged for powering said LED light sources <NUM>, or alternatively to provide control means or control data) will be present at the second elongated main surface <NUM> of the elongated carrier <NUM> and thereby not interrupting the line-lighting provided by said LED light sources <NUM> along the first elongated main surface <NUM> of the elongated carrier <NUM>. Hence, the present invention may provide an advantageous and improved lighting module <NUM> for line-lighting applications.

Furthermore, still referring to <FIG>, the flexible circuit <NUM> is folded around the second end-face <NUM>. Said folding renders (or: results in) a fold <NUM>. This fold <NUM> is located at the interface between the first section <NUM> of the flexible circuit <NUM> and the second section <NUM> of the flexible circuit <NUM>, which interface is a clear boundary between the connector <NUM> and its connecting function (at the second surface) and the plurality of LED light sources <NUM> and its line-lighting function. Alternatively, the flexible circuit may be folded around the second end-face, wherein the fold is located at the first section of the flexible circuit. In this situation, it is ensured that the second section accommodating the connector is fully located on the second elongated main surface.

<FIG> depicts schematically a cross-sectional-view of a second embodiment of a lighting module <NUM>, which is partly similar to the embodiment depicted in <FIG>. Here, the lighting module <NUM> comprises again an elongated carrier <NUM> and a flexible circuit <NUM>. The elongated carrier <NUM> comprises a first end-face <NUM> and a second end-face <NUM>, and extending therebetween a first elongated main surface <NUM> and a second elongated main surface <NUM>. The second elongated main surface <NUM> and the first elongated main surface <NUM> are opposite to each other. The materials and dimensions of the elongated carrier <NUM> of the lighting module <NUM> are similar to the embodiment depicted in <FIG>.

Here, the flexible circuit <NUM> comprises a first section <NUM> accommodating a plurality of LED light sources <NUM>, a second section <NUM> accommodating a connector <NUM> for receiving power to power the plurality of LED light sources, a third section <NUM> accommodating a further connector <NUM> for receiving power to power the plurality of LED light sources. The first section <NUM> of the flexible circuit <NUM> is connected to said first elongated main surface <NUM>, and the second section <NUM> of the flexible circuit <NUM> and the third section <NUM> of the flexible circuit <NUM> are both connected to said second elongated main surface <NUM>. Here, the first section <NUM> of the flexible circuit <NUM> is located between said second section <NUM> and said third section <NUM>. The flexible circuit <NUM> is therefore a strip which is partitioned into three parts, having their own electrical purpose / task / functioning. Here, said connector <NUM> and said further connector <NUM> are electrodes embedded in the circuitry of the flexible circuit.

Referring to <FIG>, thereto, the flexible circuit <NUM> is folded around the second end-face <NUM> by means of a fold <NUM> and folded around the first end-face <NUM> by means of a further fold <NUM>. The first fold is located at the first section <NUM> of the flexible circuit <NUM>, such that no undesired bending or folding is needed at the second section <NUM> nor the third section <NUM>, which accommodate respectively the connector <NUM> and the further connector <NUM>. The connector and the further connector extend at least partly in the first section (not explicitly depicted here). Alternatively, said folds may be present at the interface between the first section and respectively the third section and second section.

Still referring to <FIG>, additionally, the first end-face <NUM> and the second end-face <NUM> of the elongated carrier <NUM> both comprise a recess <NUM> for folding around the flexible circuit <NUM>. Thus, the fold <NUM> and the further fold <NUM> are comprised within said recess <NUM>, which protects said folds <NUM>, <NUM> from wear and possible damage; for example, when the lighting module is mounted in e.g. a luminaire abutting an edge or another lighting module. Here, the recess <NUM> is a stepped recess, but may alternatively be an incurvature. The depth of the recess is equal to <NUM> millimeter, which is at least twice the thickness of the flexible circuit, which was <NUM> millimeter. Moreover, in aspects, said recess may also comprise a depth taking into account possible application of adhesive tape required to attach said flexible circuit. Alternative dimensions may be envisioned. The recess may alternatively serve as a connection means for detachably fixating the lighting module in e.g. a luminaire, or a matching connecting unit; for example, the outer edges of the end-faces (not the recessed part) may fit into a holder.

Thus, both the connector <NUM> as well as the further connector <NUM> are arranged to receive power to power said plurality of LED light sources, whereas only one of those or both may be powering the LED light sources when in operation. Hereby, a lighting module is established which is capable of being connected to receive power via either the first connector, the second connector, or both. Mounting and operability is hence facilitated. Moreover, whenever a first connector fails within e.g. a troffer, the lighting module may easily be detached from the troffer, rotated, and mounted again in the troffer with the second connector performing the function of the failed first connector.

<FIG> depicts schematically, by non-limiting example, a perspective-view of a third, alternative, embodiment of a lighting module <NUM> according to the invention, which is partly similar to the embodiments depicted in <FIG> and <FIG>. The lighting module <NUM> comprises the flexible carrier <NUM>. Here, however, the flexible circuit <NUM> comprises the elongated carrier <NUM>; which are in assembly. Said assembly is a plate-shaped elongated strip. Such an assembly may be established when manufacturing or producing said flexible circuit <NUM>. The elongated carrier <NUM> is therefore a reinforcing layer of the flexible circuit <NUM>, which is a copper layer, but alternatively may be any other layer such as polymer or metal, or fiber reinforced polymer. The elongated carrier <NUM> and the flexible circuit are bond by means of an adhesive, but may alternatively be bond by pressing or another bonding technique. Here, the flexible circuit <NUM> has a thickness of <NUM> millimeter and the elongated carrier <NUM> comprised therein comprises a thickness of <NUM> millimeter. Alternatively, other layers may be present in the flexible circuit, such as a laminate of reinforcing layers, di-electric layers, thermal layers, insulation layers, etc. The elongated carrier <NUM> comprises a first end-face <NUM> and a second end-face <NUM>, and extending therebetween comprises a first elongated main surface <NUM> and a second elongated main surface <NUM>. The lighting module is <NUM> centimeters in length, i.e. the shortest distance between the first end-face and the second end-face. The second elongated main surface <NUM> is opposite to said first elongated main surface <NUM>.

Similarly, as before, the flexible circuit <NUM> also comprises a first section <NUM> accommodating a plurality of LED light sources <NUM> and a second section <NUM> accommodating a connector <NUM> for receiving power to power the plurality of LED light sources <NUM>. The LED light sources <NUM> are arranged on the lighting module <NUM> in two lines next to each other. Said first section <NUM> and said second section <NUM> are part of the circuitry layer of the flexible circuit <NUM>, whereas the elongated carrier <NUM> is part of the reinforcing layer (hence not containing any electronic/circuitry function) of the flexible circuit <NUM>. The first section <NUM> of the flexible circuit <NUM> is connected to a first elongated main surface <NUM> of the elongated carrier <NUM>. The second section <NUM> of the flexible circuit <NUM> is connected to said second elongated main surface <NUM>. The first section <NUM> accommodates a plurality of LED light sources, but may alternatively host other components in the circuitry required to control or drive for example the LED light sources. The second section <NUM> accommodates a connector <NUM>, which is an electric track with electrodes embedded within the circuitry of the flexible circuit <NUM>. The connector (i.e. the electric track) extends at least partly in the first section.

The cross-section of the elongated carrier <NUM> comprises a curvature for improving the stiffness of the lighting module <NUM>. The curvature comprises an angle of <NUM> degrees, but may alternatively be an angle between <NUM> degrees and <NUM> degrees. Thereby, the deflection of the lighting module <NUM> in elongated direction is reduced. Namely, the deflection of the second end-face in respect to the first end-face (which is constrained in all its degrees of freedom) is not greater than <NUM> centimeters.

Furthermore, still referring to <FIG>, the layer containing the first section <NUM> and the second section <NUM> of the flexible circuit <NUM> is folded around the second end-face <NUM>. Said folding renders (or: results in) a fold <NUM>. This fold <NUM> is located at the interface between the first section <NUM> of the flexible circuit <NUM> and the second section <NUM> of the flexible circuit <NUM>, which interface is a clear boundary between the connector <NUM> and its connecting function and the plurality of LED light sources <NUM> and its line-lighting function. Hereby, the connection function means that the connector is present and is arranged for receiving power to power said plurality of LED light sources. Hence, a clear hierarchy of layers is established for the lighting module <NUM>, wherein the flexible circuit <NUM> comprises at least a layer with the first section <NUM>, the elongated carrier <NUM> reinforcing said layer thereunder, and at the second end close to the second end-face <NUM> there is the back-folded layer with the second section <NUM>.

<FIG> depicts schematically, by non-limiting example, an embodiment of a lighting device <NUM> according to the invention. The lighting device <NUM> comprises a housing <NUM>, such as e.g. a troffer or a luminaire casing. The housing <NUM> comprises and/or accommodates a lighting module <NUM> according to the invention and a connecting unit <NUM>. The lighting module <NUM> is detachably fixated to said connecting unit <NUM> by means of a slot (not depicted) comprised by the connecting unit <NUM>. Said slot (not depicted) may be accessible by means of pressing the lighting module <NUM> through teeth, which may result in a common click connection. Hence, the lighting module <NUM> is detachably fixated and/or connected to said connecting unit <NUM> by means of a click connection. Alternatively, other connecting means may be envisioned such as sliding, gluing, press-fitting, Velcro, etc..

Furthermore, the housing <NUM> comprises and/or accommodates a further lighting module <NUM> and a corresponding further connecting unit <NUM>. As the lighting modules may be standardized, the lighting modules and connecting units may be interchangeable and compatible with each other. Hence, the lighting device <NUM> and its housing <NUM> comprise, in this example, two lighting modules <NUM>, <NUM> mounted therein. Alternatively, any other applicable number of lighting modules may be mounted into the lighting device. Here, the further lighting module <NUM> is also similarly detachably fixated to its respective connecting unit <NUM> by means of a slot (not depicted) comprised by the further connecting unit <NUM>. Consequently, the lighting modules <NUM>, <NUM> may be easily attached and/or detached to/from the lighting device <NUM>, which facilitates the replaceability or serviceability of the lighting device <NUM>.

Referring to <FIG>, as mentioned, the lighting device <NUM> comprises within its housing <NUM> the lighting module <NUM> and the further lighting module <NUM>, which are respectively received by and detachably fixated to the connecting unit <NUM> and the further connecting unit <NUM>. The connecting unit <NUM> comprises a connecting area <NUM>; and similarly, the further connecting unit comprises a further connecting area <NUM>. Said connecting areas <NUM>, <NUM> are electrodes, which may e.g. be spring-loaded by a spring means so as to press against any connecting connector. Said electrodes may alternatively be connectors, tracks, pins, terminals, etc. The connector <NUM> of the lighting module <NUM>, which is an electrode (or alternatively: electric track) within the circuit of the flexible circuit <NUM> of the lighting unit <NUM>, is thereby electrically connecting to the connecting area <NUM> of the connecting unit <NUM>. The same applies for the connector (not depicted due to blocking perspective of the further connecting unit <NUM>, not a see-through applied) of the flexible circuit <NUM> of the lighting unit <NUM>, which connector is electrically connecting to the further connecting area <NUM> of the further connecting unit <NUM>.

Still referring to <FIG>, the second end-face <NUM> of the lighting module <NUM> abuts with a wall of the housing <NUM>. The first end-face <NUM> of the further lighting module abuts with a wall of the housing <NUM>. Moreover, the first end-face <NUM> of the lighting module <NUM> abuts with the second end-face <NUM> of the further lighting module <NUM>. Alternatively, the lighting module may for example comprise a recess, as mentioned before, such that said abutting does not damage or wear the bend of the bent flexible circuit.

Thus, the present invention provides an improved lighting module, which may be more easily mounted in a lighting device such as e.g. a luminaire or a troffer. Since the connector <NUM> of the lighting module <NUM> is located at the respective second elongated main surface <NUM> opposite to the first elongated main surface <NUM> having the plurality of LED light sources <NUM>, the lighting module <NUM> may easily be fitted and/or mounted via said second elongated main surface <NUM> having respectively the connector <NUM>, while still keeping an uninterrupted continuous line of light via the first elongated main surface <NUM> having the plurality of LED light sources <NUM>. The same applies to the further lighting module <NUM> mutatis mutandis.

Thus, the lighting device <NUM> accommodates a plurality of lighting modules <NUM>, <NUM>, which are arranged back to back. Here, each module <NUM>, <NUM> has its own respective connecting unit <NUM>, <NUM>. Alternatively, at least one connecting unit may be configured to electrically connect the connector of a respective first lighting module and the connector of a respective second lighting module with its connecting area.

Still referring to <FIG>, the lighting device <NUM> further comprises a lighting driver <NUM> for providing power. Each connecting unit <NUM>, <NUM> is arranged to receive power from said lighting driver <NUM> and relay said power to the respective lighting module <NUM>, <NUM>. Alternatively, said driver may be a controller for providing control commands to each respective lighting module via said connecting unit, its connecting area and the respective connector.

Moreover, each lighting module according to the present invention may be comprised within a lighting device comprising a connecting unit.

<FIG> depicts schematically, by non-limiting example, within a flowchart, a method <NUM> of manufacturing a lighting module comprising a flexible circuit and an elongated carrier. The elongated carrier comprises first end-face and a second end-face, and extending therebetween comprises a first elongated main surface and a second elongated main surface, the second elongated main surface being opposite to said first elongated main surface. The method <NUM> comprises the step of <NUM> connecting a first section of a flexible circuit to the first elongated main surface of the elongated carrier, wherein the first section accommodates a plurality of LED light sources. Subsequently, a second step is: <NUM> folding the flexible circuit around the second end-face of the elongated carrier. A further step is: <NUM> connecting a second section of the flexible circuit to the second elongated main surface of the elongated carrier, wherein the second section accommodates a connector for receiving power to power said plurality of LED light sources.

Claim 1:
A lighting module (<NUM>,<NUM>) comprising an elongated carrier (<NUM>,<NUM>) and a flexible circuit (<NUM>,<NUM>);
wherein the flexible circuit (<NUM>,<NUM>) comprises a first section (<NUM>,<NUM>) accommodating a plurality of LED light sources (<NUM>,<NUM>), a second section (<NUM>,<NUM>) and a connector (<NUM>,<NUM>);
wherein the connector is accommodated in the second section for receiving power to power said plurality of LED light sources (<NUM>,<NUM>) and extends at least partly in the first section;
wherein the elongated carrier (<NUM>,<NUM>) comprises first end-face (<NUM>,<NUM>) and a second end-face (<NUM>,<NUM>), and extending therebetween comprises a first elongated main surface (<NUM>,<NUM>) and a second elongated main surface (<NUM>,<NUM>), the second elongated main surface (<NUM>,<NUM>) being opposite to said first elongated main surface (<NUM>,<NUM>);
wherein the first section (<NUM>,<NUM>) of the flexible circuit (<NUM>,<NUM>) is connected to said first elongated main surface (<NUM>,<NUM>), and wherein the second section (<NUM>,<NUM>) of the flexible circuit (<NUM>,<NUM>) is connected to said second elongated main surface (<NUM>,<NUM>);
wherein the elongated carrier comprises at least one rim arranged on the first elongated main surface, wherein the at least one rim extends continuously between the first end-face and the second end-face;
characterized in that the at least one rim is a lightguide.