The present invention concerns an apparatus and the corresponding method for the automated finishing of photovoltaic modules or strings, of the type typically consisting of a plurality of photovoltaic cells electrically connected to each other by means of conductive tracks. BACKGROUND OF THE INVENTION

Photovoltaic modules, or panels, are known, that is, electronic devices formed by a sandwich of various materials, including glass, vinyl material, polymeric material or others, with interposed desired photovoltaic strings typically consisting, in turn, of photovoltaic cells, the latter electrically connected to each other by conductive tracks.

For the purposes of a thorough disclosure, these multi-material sandwiches are subjected to hot lamination in order to be compacted together and define the photovoltaic module itself, which undergoes subsequent operations of finishing, framing and electronic connection, to perform its known functions. In the construction sector, there is an increasing need to integrate photovoltaic modules with the finishes of the building work, in such a way that they are integrated completely, especially from the point of view of the overall design of the building. This design and construction methodology is known by the English acronym BIPV (Building Integrated Photo Voltaic). However, one of the greatest limits to the expansion of this methodology is posed by the typical design of photovoltaic modules in which, because of their functional requirement, the photovoltaic cells are substantially visible, with the conductive tracks evidently visible, even generating unwanted reflections which are sometimes dangerous for the operation of passing vehicles, or creating chromatic contrasts or design lines that do not match the building context in which the photovoltaic module itself is integrated.

Some known solutions have been proposed, including that of using conductive tracks that are already opaque or pigmented with a black color before application on the cells, so as to minimize reflections and the aesthetic impact that these conductive tracks normally have on the photovoltaic module.

However, the pre-pigmented conductive tracks tend to lose their color as soon as they are applied to the photovoltaic cells, since during their application they are subjected to thermal and mechanical stress which causes them to lose their darkening pigments, with unsatisfactory final results.

Another known solution is to use a black adhesive tape, also known simply by the English term “tape”, which is deposited to cover the conductive tracks.

However, the latter solution poses problems and difficulties in terms of automation and reliability, as well as duration over time, compromising the productivity of the supply chain and the quality of the final products.

There is therefore the need to perfect an apparatus and to devise a method for the automated finishing of photovoltaic modules or photovoltaic strings which can overcome at least one of the disadvantages of the state of the art. To do this, it is necessary to solve the technical problem of pigmenting the conductive connection tracks between the photovoltaic cells as desired, so as to coat them in order to prevent unwanted reflections and aesthetic effects that limit the potential applications of photovoltaic modules in building integration.

In particular, one purpose of the present invention is to provide an apparatus and perfect a method for the automated finishing of photovoltaic modules or strings, in which the conductive tracks are coated after their application to the photovoltaic cells, giving them a desired color and minimizing the natural reflectance of the conductive tracks.

Another purpose of the present invention is to provide an apparatus which allows to give repeatability and high quality to the photovoltaic module thus produced.

Another purpose of the present invention is to allow a high customization of the covering of the conductive tracks, so as to allow the maximum possible integration of the photovoltaic module thus produced with the building context in which it is installed.

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. The dependent claims describe other characteristics of the present invention or variants to the main inventive idea. In accordance with the above purposes and to resolve the technical problem disclosed above in a new and original way, also achieving considerable advantages compared to the state of the prior art, an apparatus according to the present invention for the automated finishing of photovoltaic modules or photovoltaic strings comprises at least one operating plane with respect to which the photovoltaic modules or strings are positioned, and a printing unit disposed above the operating plane, mobile in a determinate printing direction in such a way as to deposit at least one layer of coating material in correspondence with conductive tracks of the photovoltaic modules or strings.

In this way, the layer of coating material is deposited on the conductive tracks after these are associated with the individual photovoltaic cells, so as to allow an automated covering thereof, giving them a desired color and minimizing the natural reflectance of the conductive tracks themselves.

This advantageous aspect of the present invention allows for a high customization of the covering of the conductive tracks, so as to allow the maximum possible integration of the photovoltaic module thus created with the building context in which it is installed.

Moreover, by depositing the layer of coating material according to the present invention, there is also the advantage of achieving repeatability and high quality of the photovoltaic module thus produced. In accordance with another aspect of the present invention, the coating material comprises an ink that can be polymerized by means of UV rays.

In accordance with another aspect of the present invention, the apparatus comprises at least one radiation unit disposed mobile together with the printing unit, so as to irradiate UV rays and/or IR rays onto the polymerizable ink deposited on the conductive tracks.

In accordance with another aspect of the present invention, the printing unit comprises one or several printing heads facing toward the operating plane in a condition whereby they surmount the corresponding conductive track on which to deposit the coating material. Advantageously, each printing head comprises a plurality of nozzles disposed on one or more rows and able to deliver the coating material onto the conductive tracks.

This advantageous aspect of the present invention allows for greater coating precision, which can also be customized according to the layout of the conductive tracks to be coated, making the apparatus according to the present invention substantially universal for all types of photovoltaic modules.

In accordance with another aspect of the present invention, the radiation unit comprises at least one UV lamp disposed in cooperation with the printing unit in such a way as to irradiate UV rays onto the polymerizable ink deposited on the conductive tracks. The radiation unit also comprises at least one IR lamp disposed in cooperation with the printing unit in such a way as to irradiate IR rays onto the polymerizable ink deposited on the conductive tracks.

The installation of two radiation units, one downstream and one upstream of the printing unit, allows to deposit the polymerizable ink both in a first, forward, pass and also in a second, return, pass, consequently optimizing operating times.

This solution is particularly advantageous in operating conditions in which the conductive tracks need a double layer of coating material, for example to better resist the subsequent lamination steps for forming the photovoltaic panel. In fact, with the solution according to the present invention, instead of carrying out a first pass to deposit the ink and irradiating the UV rays, returning the printing unit to the starting position and, subsequently, carrying out a second pass, only two passes are performed, eliminating a machine time.

In accordance with another aspect of the present invention, the apparatus comprises at least one unit rotating with respect to the printing direction, with which the printing unit and/or the at least one radiation unit are able to be associated.

The invention also concerns a method for the automated finishing of photovoltaic modules or photovoltaic strings, in which there is provided at least a first step of positioning the photovoltaic modules or strings on an operating plane; and a second step of depositing at least one layer of coating material in correspondence with conductive tracks of the photovoltaic modules or strings, by means of a printing unit disposed above the operating plane and mobile in a determinate printing direction.

DESCRIPTION OF THE DRAWINGS

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

- fig. 1 is a three-dimensional view of an apparatus for the automated finishing of photovoltaic modules, according to the present invention;

- fig. 2 is an example view of a photovoltaic module;

- fig. 3 is a top view of the apparatus of fig. 1 , in a starting operating condition; - fig. 4 is a top view of the apparatus of fig. 1 , in a working operating condition;

- fig. 5 is a detailed view from below of a detail of the apparatus of fig. 1;

- fig. 6 is an example lateral view of a variant of fig. 5.

We must clarify that in the present description the phraseology and terminology used, as well as the figures in the attached drawings also as described, have the sole function of better illustrating and explaining the present invention, their function being to provide a non-limiting example of the invention itself, since the scope of protection is defined by the claims.

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 be conveniently combined or incorporated into other embodiments without further clarifications.

DESCRIPTION OF AN EMBODIMENT OF THE PRESENT INVENTION

With reference to fig. 1, an apparatus 10 according to the present invention is used to finish photovoltaic modules 15, or photovoltaic strings 11. With particular reference to fig. 2, and for descriptive purposes only, the photovoltaic modules 15 are defined by a plurality of photovoltaic strings 11 , which in turn consist of a series of photovoltaic cells 12 electrically connected to each other by a plurality of conductive tracks 13. The latter define the circuit through which the electric energy is conveyed toward the normal management electronics (of a substantially known type and not shown).

With reference to fig. 1, the apparatus 10 substantially comprises an operating plane 16, a printing unit 17, two UV lamps 19 and a manipulator 20.

The operating plane 16 is conformed to accommodate and keep one or more photovoltaic strings 11 in a desired position. According to one variant, not shown in the drawings, the operating plane 16 could be conformed to accommodate one or more photovoltaic modules 15.

In particular, the operating plane 16 comprises a rest surface 21 and two mechanic abutments 22, disposed, respectively, on opposite sides of the rest surface 21. Furthermore, the rest surface 21 comprises a plurality of holes 23 which are connected to a suction circuit which, as will be explained in detail below, allow to keep the photovoltaic strings 11 in a desired operating position.

The printing unit 17 is conformed to deposit one or more layers of UV-ray polymerizable ink on the conductive tracks 13 of the photovoltaic strings 11 disposed on the operating plane 16. In particular, the printing unit 17 is mounted on a slider 25, the latter selectively mobile in a printing direction P which, in the embodiment shown, extends both from left to right and also from right to left, with particular reference to fig. 4, so as to allow to deposit several layers of ink with passes in sequence.

With reference to fig. 5, the printing unit 17 comprises a plurality of heads 26, in this case three, disposed facing the rest surface 21 and operatively surmounting the conductive tracks 13 of the photovoltaic modules 15 disposed on the rest surface 21. Each head 26 is internally equipped with a high density of nozzles 27, disposed in one or more horizontal lines, which guarantee high printing precision and correct ink dosage.

Advantageously, the size of the heads 26 is such as to define a substantial surmounting of the lines of nozzles, with respect to the printing direction P, so as to guarantee printing substantially on any point of the width of the photovoltaic string 11.

With the printing unit 17 there is also associated a special tank (not shown in detail) inside which the ink is stored. The latter is put into circulation thanks to a suitably sized hydraulic system, to be subsequently deposited on the conductive tracks with precision by means of the nozzles 27.

The UV lamps 19 are suitable to irradiate the photovoltaic strings 11 after the ink has been deposited and they emit a radiation of a certain wavelength, also according to the ink, so as to allow the ink itself to solidify, obtaining the desired finish.

In particular, the UV lamps 19 are mounted on the slider 25, in positions adjacent to the printing unit 17 in line with the printing directions P. The UV lamps 19, of a substantially known type, can be selectively inclined with respect to the rest surface 21, so as to define a desired operating angle of irradiation.

The manipulator 20 is disposed in cooperation with the operating plane 16 and is conformed to automatically remove the photovoltaic strings 11 from the rest surface 21, turn them over, and take them to an evacuation position.

In particular, the manipulator 20 comprises a plurality of arms 29 which, on one side, are rotatably keyed to a shaft 30 and, on the other side, support a gripping plane 32.

The latter is provided with a plurality of suckers 33 of the pneumatic type, suitable to temporarily hold at least one photovoltaic string 11, at least in the passage between a condition whereby it is loaded onto the gripping plane 32 and a condition whereby the photovoltaic string 11 is deposited for the subsequent evacuation.

The operation of the apparatus 10 described heretofore, which corresponds to the method according to the present invention, comprises the following steps.

Initially, at least one photovoltaic string 11 is positioned on the rest surface 21 by means of an automation.

In this operating condition, the photovoltaic string 11 is deliberately aligned on the rest surface 21, by means of the mechanic abutments 22. At the end of this operation, the suction circuit is activated so as to generate a depression between the photovoltaic string 11 and the rest surface 21, through the holes 23, so as to keep the string on the rest surface 21.

The operating pattern of the nozzles 27 of the heads 26 is programmed by means of a command and control unit 36, in such a way as to deposit the ink exactly on top of the conductive tracks 13, retracing the layout thereof.

This operating functionality allows to hide the conductive tracks 13 effectively. Again by means of the command and control unit 36, it is possible to determine the number of deposit passes to be carried out, also according to the operational needs of the photovoltaic module 15, the subsequent manufacturing steps, or the type of color and/or aesthetic effect to be achieved. For example, an advantageous function of the apparatus 10 according to the present invention is that of providing to deposit one or more layers of ink, in order to make the color opaque and resistant to the normal lamination sequence.

Moreover, some optimal parameters of the printing layout can be pre- configured, or determined automatically, in order to:

(a) compensate for any misalignments of the conductive tracks 13, caused by the upstream processes;

(b) minimize spillages of ink beyond the edges of the useful surface of the photovoltaic cell 12, which would decrease the yield of the finished module; (c) have a maximum coverage of the conductive tracks 13.

According to a variant not shown, it is possible to provide one or more transducers associated with the slider 25, which allow to detect with optical, electromagnetic or other technology the real layout of the conductive tracks 13, so as to guarantee greater precision in depositing the ink on the conductive tracks 13. Immediately following the deposit of the ink, its polymerization by means of the UV lamps 19 follows.

With reference to figs. 3 and 4, if the printing direction P goes from left to right, the UV lamp 19 to the left of the printing unit 17 is activated; conversely, if the printing direction P goes from right to left, the UV lamp 19 to the right of the printing unit 17 is activated.

This substantially guarantees a swift polymerization of the ink deposited on the conductive tracks 13 , minimizing the possibility that the ink itself leaks outside the intended path which could, as mentioned, partly compromise the yield of the photovoltaic cell 12. Downstream of the previous processes, the rotation of the shaft 30 is activated, for example by means of a traditional rotary actuator of the electronic or pneumatic type, or other, so that the gripping plane 32 is turned over by the arms 29, until it reaches a position whereby it surmounts the photovoltaic string 11 positioned on the rest surface 21. The suckers 33 are then activated in order to hold the photovoltaic string 11 on the gripping plane 32.

The rotation of the shaft 30 is then activated again, so that the gripping plane 32 is rotated by the arms 29 in such a way as to turn over the photovoltaic string 11 and take it to an evacuation position. It is clear that modifications and/or additions of parts may be made to the apparatus 10 and to the method as described heretofore, without departing from the field and scope of the present invention, as defined by the claims.

For example, according to one variant of the present invention, a single UV lamp 19 is provided, disposed downstream of the printing unit 17 with reference to the printing direction P.

According to the variant shown in fig. 6, the UV lamps 19 are associated with the same number of IR (Infra-Red) radiation lamps 35 so that, once the operating direction of the printing unit 17 has been fixed, the zone where the ink is deposited first encounters the UV beam and then the IR beam. With this solution, it is possible to increase the flow of heat transmitted during the printing process and thus allow a faster drying of the color layer, in addition to the polymerization process initiated by the UV radiation.

According to another variant, in order to limit the production costs due mainly to the UV lamps 19, a single UV lamp is used, mounted together with the printing unit into an assembly capable of rotating.

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 will be able to achieve other equivalent forms of apparatus for the automated finishing of photovoltaic modules or photovoltaic strings, and corresponding finishing 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 their reading and they must not be considered as restrictive factors with regard to the field of protection defined by the claims.