FIELD OF THE INVENTION

Embodiments described here concern a lighting strip and the corresponding production method. The invention is applied in particular in the field of lighting technology to produce lighting strips that support, on their length, light sources, for example but not only LEDs (Light Emitting Diodes).

Said strips can be applied to profiles, tables, panels, furnishing components in general, portions of walls, ceilings and false ceilings, and in other various applications, internal or external, where there is a desire to achieve particular aesthetic and/or focused and/or distributed lighting effects.

BACKGROUND OF THE INVENTION

Lighting strips that can be used in the lighting technology and furnishing sector to produce points/zones of light distributed in specific portions of wall elements or furnishing components are known.

The development of LED and OLED (Organic LED) technology, together with increasingly advanced architectural requirements and ideas, has allowed technologically advanced solutions to develop, allowing the creation of extremely sophisticated lighting effects, in particular in combination with profiles and edges of furnishing components, as well as of doors or window frames, partitions, external walls and other.

A lighting strip of this type normally consists of a longitudinal support, with a length greater than its width, made of normally flexible material on which a thin copper coating is applied, in a single or double layer, which creates the conductive track or tracks for the power supply of light sources.

This combination of flexible support and conductive coating forms a so-called PCB (Printed Circuit Board) on which the light sources, as well as the corresponding electrical/ electronic power supply and management components, are applied, and from which the light sources obtain the electric power supply.

In correspondence with the positioning of the light sources, a base made of rigid material is normally provided, which forms a stable support to correctly position the light sources and hold them in position, and guarantees the necessary mechanical seal of the strip as well as of the welds and electric connections. Once the desired disposition of the light sources is achieved, the strip is coupled to a profile made of PVC or silicone, and the whole is then drowned in a resin, or similar material, which seals and defines the final shape of the strip.

This resin, usually in silicone material, guarantees a high electrical insulation, making the strip applicable also outdoors.

One problem encountered in known solutions is the poor capacity of the strip, once its production is completed, to be flexed and bent with respect to at least two planes in space, for example to form a three-dimensional luminous element, since the internal rigidity of the connections could cause them to break and/or the electrical connections to be interrupted.

Other lighting devices are known from US-A-2015/0176786 (US’786), WO- A-2014/026976 (WO’976) and WO-A-03/019506 (WO’506).

US’786 describes a system to simulate neon light comprising an elongated guide provided with an external surface and a channel; a housing containing a coupling member and an area to receive the lighting device, and the lighting device. The latter comprises a flexible printed circuit (FCB) and a plurality of LED lights attached to the FCB, and a plurality of electrical connectors all in contact with the power conductor. The solution described in US’786, however, is not very flexible, as the support connectors and the power conductor are bulky and do not allow to bend the device other than to a minimum extent, and even in this case only in one direction, that is, with respect to the plane containing the FCB.

WO’976 describes an LED module comprising a strip-shaped base element which comprises a strip- shaped printed circuit to which a plurality of LEDs is coupled, wherein the base element is flexible and can be plastically deformed. The LED module described in WO’976 can be curved only with respect to the plane containing the base, possibly forming a helical coil, but cannot be curved with respect to a plane orthogonal thereto.

This constitutes a limitation in the possible applications and installations of the strips, which are therefore sometimes not able to satisfy the ever more evolving needs and demands of architects and interior designers.

One purpose of the present invention is therefore to provide a lighting strip that increases the degree of flexibility and torsion with respect to known solutions, allowing it to be folded on several planes with respect to space, with wide degrees of freedom and without risks of breakage, seal of the welds, formation of cracks and interruptions, even only partial, of the electrical connections.

Another purpose of the present invention is to perfect a method to produce said strips which is in any case fast and economical, while at the same time guaranteeing that the advantages indicated above are obtained.

Another purpose is to obtain a lighting strip that can be folded on at least two planes, in which neither the correct optical emission of the light sources nor the continuity of the light and/or the correct maintenance of a regular and constant pitch between the light sources is compromised.

In particular, the purpose of the present invention is to obtain a lighting strip that can be bent/folded both on a plane transverse to a base surface of the strip, and also on the plane that contains the base surface itself, allowing to obtain a plurality of three-dimensional shapes.

The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.

SUMMARY OF THE INVENTION

The present invention is set forth and characterized in the independent claims, while the dependent claims describe other characteristics of the invention or variants to the main inventive idea.

In accordance with the above purposes, a lighting strip according to the present invention comprises a longitudinal support element, made of flexible material, on a first side of which a coating of conductive material is applied, for example copper.

In a possible non-restrictive solution, the support in flexible material is made of a flexible polymeric material.

According to further embodiments, the flexible support is at least partially made of Kapton.

The light sources, for example of a point-shaped or substantially point-shaped type, are applied in pre-established positions, provided in the design of the lighting strip. In a preferred non-restrictive embodiment, the light sources consist of LEDs or OLEDs, or another type of similar or comparable source.

Bases made of rigid material are associated with the flexible longitudinal support element in correspondence with the position of the light sources, on the opposite side with respect to the conductive coating, and define the correct positioning and guarantee the necessary mechanical seal for the light sources.

The lighting strip thus made, formed by the longitudinal support element, the conductive coating, the light sources and the corresponding bases, is then normally applied to an open profile, for example but not necessarily made of flexible polymeric material, to define a substantially U-shaped or C-shaped shape, or other similar or comparable shape.

According to some embodiments, the flexible polymeric material can be, for example, PVC or silicone.

Upon completion of the shaping procedure, the strip is then drowned in a cover, for example made of polyurethane resin or silicone, which closes the open profile, enclosing the light sources for the purpose of containment and protection and providing the final shape to the strip.

According to one aspect of the present invention, the flexible longitudinal support element is made with a plurality of folds, or waves, which separate adjacent rectilinear segments.

The presence of such folds allows, also in steps that follow the coupling with the open profile in PVC/silicone and/or the application and stabilization of the layer of polyurethane resin/silicone, to flex and fold the lighting strip on two or more planes in space, according to the specific shape to be taken for the specific application.

In this way, the lighting strip is perfectly adaptable and moldable to follow even the most particular and complex shapes and profiles, for example an edge of a curvilinear furnishing component, also irregular, a profile of a shutter also folded at 90°, a profile of an internal or external wall, or whatever else required by the specific application.

According to some embodiments, the zones of the flexible support element which define the folds are smaller in width than the rectilinear segments on which the light sources and the bases are applied. Providing a smaller width for the folds allows to obtain greater folding flexibility of the lighting strip, thus allowing it to be bent and folded so as to form a circle or other curved shape, on a plane that contains all the rectilinear segments, or the base surface of the lighting strip.

According to some embodiments, the width of the folds is less than or equal to 50% of the width of the rectilinear segments.

According to some embodiments, the width of the folds is comprised between about 20% and about 50% of the width of the rectilinear segments.

This dimensional ratio allows to guarantee, with equal flexibility on two or more planes orthogonal to each other, both the mechanical resistance and also the electrical capacity required.

In fact, in the lighting strip according to the invention, the flexible support element consists of a printed circuit board (PCB), which acts both as a power supply and as a command for the light sources.

Thanks to this configuration, both the electrical connection and the mechanical connection of the light sources is provided by the flexible support element, therefore external conductors are not required.

According to some embodiments, the number of folds on the length of the longitudinal support element can be varied in relation to the level of foldability that is required for the lighting strip, this representing a first degree of freedom which, at the design stage, the lighting strip can take in relation to the intended application.

A further degree of freedom is the depth of each fold.

The deeper the fold, the greater the level of foldability and flexibility, on at least two planes in space, of the longitudinal support element and therefore of the lighting strip once production is completed.

In a first variant, the depth of the folds is not constant on the length of the longitudinal support element, as it can be provided variable due to the desire to have a differentiated foldability/flexibility in different points of the longitudinal support element.

In a second variant, which may or may not be combined with the first variant, the frequency of the folds on the length of the longitudinal support element, that is, the distance between two adjacent folds, is not constant, also in this case to create zones of differentiated foldability/flexibility on the length of the longitudinal support element.

Solutions in which all the folds have the same depth, and/or their frequency on the length of the longitudinal support element is constant, naturally come within the field of protection of the invention.

According to the invention, both the depth of the folds and their frequency are defined in the design step of the strip, in relation to the pitch that the LEDs must have in the final configuration of the strip itself, since the step of folding or puckering the longitudinal support element modifies the pitch between the LEDs and determines its final value.

It is within the scope of the invention that the method to make the folds on the longitudinal support element provides to use a measuring instrument, for example a template, which allows to verify that the desired value of the pitch between the light sources which, following the formation of said folds, are brought closer to each other, has been achieved, in particular when two or more longitudinally spaced LEDs are present on each of the rigid bases.

In this regard, for this purpose, at least one hole for the template can be present on each of the rigid bases so that bringing the bases closer to each other, with a consequent movement of the LEDs closer to each other, allows to keep the pitch between the light sources constant.

These and other aspects, characteristics and advantages of the present disclosure will be better understood with reference to the following description, drawings and attached claims. The drawings, which are integrated and form part of the present description, show some embodiments of the present invention, and together with the description, are intended to describe the principles of the disclosure.

The various aspects and characteristics described in the present description can be applied individually where possible. These individual aspects, for example aspects and characteristics described in the attached dependent claims, can be the object of divisional applications.

It is understood that any aspect or characteristic that is discovered, during the patenting process, to be already known, shall not be claimed and shall be the object of a disclaimer. BRIEF DESCRIPTION OF THE DRAWINGS

These and other characteristics of the present invention will become apparent from the following description of some embodiments, given as a non-restrictive example with reference to the attached drawings wherein:

- fig. 1 shows a view from above of a lighting strip in accordance with a first embodiment;

- fig. 2 is a longitudinal section according to A-A of fig. 1 ;

- fig. 3 is a schematic view of part of the lighting strip in an unassembled condition;

- fig. 4 is a cross section according to B-B of fig. 1 ;

- fig. 5 is a variant of fig. 3 in a second embodiment;

- fig. 6 is another variant of fig. 3 in a third embodiment;

- fig. 7 is another variant of fig. 3 in a fourth embodiment;

- fig. 8 is another variant of fig. 3 in a fifth embodiment;

- fig. 9 is an enlarged view of part of fig. 2;

- fig. 10 is a possible example conformation that the lighting strip can take;

- fig. 11 shows another possible example folded conformation on a first plane containing a lateral surface of the lighting strip;

- fig. 12 shows a further possible example folded conformation on a second plane containing a base surface of the lighting strip.

To facilitate comprehension, the same reference numbers have been used, where possible, to identify identical common elements in the drawings. It is understood that elements and characteristics of one embodiment can conveniently be incorporated into other embodiments without further clarifications.

DETAILED DESCRIPTION OF SOME EMBODIMENTS

We will now refer in detail to the various embodiments of the present invention, of which one or more examples are shown in the attached drawings. Each example is supplied by way of illustration of the invention and shall not be understood as a limitation thereof. For example, the characteristics shown or described insomuch as they are part of one embodiment can be adopted on, or in association with, other embodiments to produce another embodiment. It is understood that the present invention shall include all such modifications and variants. Before describing these embodiments, we must also clarify that the present description is not limited in its application to details of the construction and disposition of the components as described in the following description using the attached drawings. The present description can provide other embodiments and can be obtained or executed in various other ways. We must also clarify that the phraseology and terminology used here is for the purposes of description only, and cannot be considered as limitative.

Embodiments described here, using the attached drawings, concern a lighting strip, indicated as a whole with the reference number 10 in figs. 1, 2, 4-8 and 10.

The lighting strip 10 comprises a flexible longitudinal support element 11 (PCB).

According to some embodiments, the support element 11 is at least partly made with a flexible polymeric material.

The flexible longitudinal support element 11 comprises a thin strip of plastic material 16 (for example, but not only, Kapton or comparable or similar material) coated on one side by a thin conductive layer or coating 12, for example defining one or more copper conductive tracks.

Bases 13 made of rigid material are associated, for example glued, with the flexible longitudinal support element 1 1, in positions distanced one from the other, in correspondence with which the assembly of the components, such as for example the light sources 14, point-shaped or substantially point-shaped, for example of the LED or OLED type, as well as the corresponding electrical/electronic power supply and management components, is provided.

In particular, the bases 13 are attached on a first surface of the flexible longitudinal support element 11, while the light sources 14 are attached on a second surface of the flexible longitudinal support element 11 , opposite the first surface. The conductive layer 12 is applied on the second surface and allows the electrical supply to the light sources 14.

According to some embodiments, the flexible support element 1 1 consists of a strip of printed circuit board (PCB) and provides both the mechanical support and also the electrical connection for the light sources 14.

The bases 13 guarantee the necessary mechanical resistance and resistance of the welds, thus ensuring the seal of the assembled components on the flexible longitudinal support element 11 also in conditions of use of the lighting strip 10.

In an intermediate position between one base 13 of rigid material and the other, the flexible longitudinal support element 1 1 has longitudinally folds 15 or waves, which, once the production of the lighting strip 10 is completed as will be better explained below, allow the foldability and flexibility thereof in at least two planes in space, advantageously three, to achieve the functions of lighting strip 10 which can be molded in a three-dimensional direction according to the desired applications. The folds 15 separate from each other adjacent rectilinear segments 24 of the flexible longitudinal support element 11, in which the bases 13 are attached.

The folds 15 in particular allow the lighting strip 10 to be folded both on a first plane containing a lateral surface 26 thereof (fig. 10), and also on a second plane containing a lower surface 25 thereof (fig. 1 1).

According to some embodiments, the folds 15 have a width Wl, smaller than the width W2 of the rectilinear segments 24. The width W2 of the rectilinear segments can correspond to an average width of the bases 13 in a direction orthogonal to the longitudinal development of the flexible longitudinal support element 11.

According to some embodiments, the folds 15 have a width Wl less than or equal to 50% of the average width W2.

The smaller the width W of the folds 15 with respect to that of the rectilinear segments 24, the greater the flexibility that they confer to the lighting strip 10, allowing it to be folded also on a plane parallel to the plane containing the rectilinear segments 24 and to the lower surface 25 (fig. 11).

In fact, the smaller the size of the width W of the folds 15, the closer adjacent rectilinear segments 24 can be brought to each other, without inducing excessive mechanical stresses on the flexible support element 1 1 , allowing to obtain a wide range of bending radiuses.

According to further embodiments, the folds 15 have a width W comprised between about 20% and about 50% of the average width WM.

Such proportions allow to guarantee both the necessary mechanical support, and a sufficient flow of electric current to power the light sources 14.

Since, for obvious reasons of assembly, as will be seen below, the folds 15 are on the side of the light sources 14, their depth must be such as to not obscure or reduce the light beam emitted by the adjacent light sources 14, while guaranteeing an adequate flexibility and torsion capacity in space.

In this way the resulting light emission is continuous and homogeneous, without the user being able to appreciate visible dots.

According to some embodiments, the depth of the folds 15 is such as to ensure that opposing edges of adjacent rectilinear segments 24 can be brought closer to each other, rotating them on a common lying plane.

According to some embodiments, in a folded condition the folds 15 have a length LI comprised between about 50% and about 90% of the length L2 which they have in their extended condition.

The folds 15 can be applied over the entire length of the flexible longitudinal support element 11, or only on a part thereof, according to the specific application of the lighting strip 10.

According to some embodiments, the folds 15, or waves, all have the same depth on the length of the flexible longitudinal support element 11.

According to variant embodiments, the folds 15, or waves, have a variable depth on the length of the flexible longitudinal support element 11.

Once said assembly has been made on the plane, the assembly consisting of flexible longitudinal support element 11, already equipped with folds 15, rigid bases 13, and light sources 14 is inserted into a containing profile 17, for example made of PVC, silicone or similar or comparable flexible plastic material. The containing profile 17 is also made of a flexible material such as to allow the shaping of the lighting strip 10 according to desired curvatures.

In the solution of fig. 4, the containing profile 17 is, by way of example, square-shaped, depending on the final shape that the lighting strip 10 must take, with the understanding that other section shapes, for example visible in figs. 5 and 7, also not regular, are still possible.

The shape of the cross-section of the containing profile 17 can be obtained by appropriately folding the latter along its oblong development.

The whole is then incorporated in a cast of resin 18, or cover, which seals and incorporates the whole, giving the strip 10 the final desired shape.

The presence of the folds 15 distributed along the length of the flexible longitudinal support element 1 1 gives the strip 10 the ability to twist and bend on two or more planes, in the specific case three planes, thus allowing the lighting strip 10 to be molded in a three-dimensional direction according to the specific applications.

With reference to figs. 1 and 9, it can be provided that the flexible longitudinal support element 11 and the bases 13 are each provided with a hole 22 for the application of a template (not shown). In this way, during the step of shaping the lighting strip, the action of the template on the holes 22 allows to shape the folds 15, by reciprocally bringing the bases 13, and therefore the light sources 14 mounted on adjacent bases 13, closer together. This allows to guarantee that the pitch P between all the light sources 14 of the strip 10 is kept constant.

For example, with reference to fig. 3 the flexible longitudinal support element 11 is shown with the bases 13 applied in its shape without any folds 15, that is, completely extended. In figs. 1 and 2, on the other hand, the folds 15 have been made in the flexible longitudinal support element 11, which have caused the bases 13 to come closer together.

In fig. 2, the reference number 19 indicates the electric cable that supplies power to the tracks of the conductive layer 12.

The variant of fig. 5 shows an embodiment similar to that of fig. 4, but in which the profile 17 has laterally ribs 19 for the recessed insertion of the lighting strip 10.

In the variant of fig. 5, in the internal space defined by the containing profile 17, secondary optics 20 are inserted before or simultaneously with the application of the resin bath 18, which allow to concentrate/direct the light beam for various applications, for example for lighting facades, lighting plants, step-lighting, and more.

In the further variant of fig. 7, on each lateral edge of the integrated, or drowned, containing profile 17, a respective cable 21 is provided, which allows the assembly of the strip 10 by laying, to create a stretched strip to be applied outdoors.

In the variant of fig. 8, a rigid support element 23 is associated below the flexible longitudinal support element 1 1 and the bases 13, which gives them rigidity for particular applications. Such rigid support element 23 can be defined by a metal sheet which extends the entire length of the flexible longitudinal support element 1 1 , and which rests thereon.

The present invention also concerns a method to produce a lighting strip 10 which comprises the steps of:

- disposing a flexible longitudinal support element 11 equipped with a conductive coating 12;

- associating with a first side of the flexible longitudinal support element 11 a plurality of bases 13 made of rigid material, distanced longitudinally with respect to each other;

- associating with a second side of the flexible longitudinal support element 11 , opposite the first side, a plurality of light sources 14 in correspondence with the bases 13, which have the function at least of positioning and stabilizing the light sources 14;

- making a plurality of folds 15, or waves, on the flexible longitudinal support element 11, in positions intermediate to the position of the rigid bases 13, wherein the width W1 of the said folds 15 is smaller than the width W2 of the rectilinear segments 24 defined by the bases 13;

- inserting the assembly of the flexible longitudinal support element 11 , equipped with folds 15, or waves, and rigid bases 13, into an open containing profile 17;

- inserting in the containing profile 17 a polyurethane resin 18 to drown in a containing and closing bath of resin 18 said flexible longitudinal support element 11.

The resin containing and closing bath defines the cast of resin 18 or cover which incorporates the flexible longitudinal support element 1 1 , the light sources 14 and the bases 13 inside the containing profile 18.

According to some embodiments, the step of creating the folds 15 on the flexible longitudinal support element 11 provides to use a series of rollers to guide the flexible longitudinal support element 1 1 under a circular punching system.

According to this embodiment, a plurality of punches can be provided, each suitable to press on the portions of the flexible longitudinal support element 11 intermediate between the adjacent rectilinear segments 24, so as to form the folds 15.

According to these embodiments, the pitch of the folds 15 is determined by the distance between each single punch inserted in the circular system.

It is clear that modifications and/or additions of parts may be made to the lighting strip 10 and to the corresponding production method as described heretofore, without departing from the field and scope of the present invention.

It is also clear that, although the present invention has been described with reference to some specific examples, a person of skill in the art shall certainly be able to achieve many other equivalent forms of lighting strip 10 and corresponding production method, having the characteristics as set forth in the claims and hence all coming within the field of protection defined thereby.

In the following claims, the sole purpose of the references in brackets is to facilitate reading: they must not be considered as restrictive factors with regard to the field of protection claimed in the specific claims.