Field of the Invention

The present invention relates to a lamp of the LED type, an acronym for the English term "Light Emitting Diode". In particular, this LED lamp is intended for all applications where large surfaces have to be lit with very high light fluxes, such as in the case of stadiums, indoor arenas, agricultural greenhouses, industrial buildings and much more. In particular it is designed to use, as light source, light-emitting diodes directly integrated into electronic boards, better known by the English term "led- chips".

Known prior art

It is well known that there are LED lamps which comprise a plurality of light sources precisely of LED-type, each provided with an electronic board having a plurality of light-emitting diodes integrated into the board (precisely of the "led-chip" type), and dissipating means to dissipate the heat produced by such electronic boards. Such dissipating means usually comprise a dissipator provided with at least one central or main portion, having a face arranged to directly contact each electronic board of the lamp and a series of fins to disperse the heat absorbed by the central portion during the operation of the light sources. These fins are usually made above the central portion and extend with respect to the latter in a direction substantially orthogonal to the surface on which the drive board lies which, as known, has a substantially planar geometry. Moreover, lamps of known art, especially to be used in lighting systems where high power is required, are also provided with at least one fan able to create an air flow which passes through the fins thereby increasing the cooling rate of the dissipator.

The solution set forth above is particularly disadvantageous if such lamps are used in environments in which there is large dust concentration. In fact, normally, such dust can settle on the fins, thus considerably reducing the efficiency of the dissipating means.

Moreover, such LED lamps can also be quite energy-consuming since not only is required to power supply both the driving circuit and the light-emitting diode, but also to power supply the fan which increases the efficiency of the cooling means.

Brief description of the invention

Starting from these premises, it is an object of the present invention to provide a LED lamp whose dissipating means are much less sensitive to the problem of dust in the environments in which they are installed.

Another object of the present invention is to provide a LED lamp which can be easily installed especially in environments where temperature regulation is needed.

Finally, object of the present invention is to provide a LED lamp which is also more efficient than those of known art.

These and yet other objects are achieved through a lamp comprising at least one light source provided with at least one electronic board having at least one light emitting diode, and dissipating means to dissipate the heat said light source produces, said dissipating means comprising at least one dissipator provided with at least one central portion having at least one face directly contacting said at least one electronic board and at least one first finned portion to disperse the heat absorbed by said at least one central portion during the operation of said at least one light source, characterized in that said at least one central portion comprises at least one through-cavity whose longitudinal axis is substantially parallel to the plane on which said at least one electronic board lies, said at least one first finned portion extending on the inner side of said at least one through-cavity.

Thanks to this solution, the problem of the dust settling on the fins and thus reducing the efficiency of the cooling means, can be prevented quite easily. In fact, the fins are made inside the through-cavity so that it is more difficult for the dust to settle on the fins and reduce, as a result, the efficiency of the cooling means.

In particular, said at least one central portion comprises a section bar provided with said at least one through-cavity.

These cooling means further comprise at least one fan arranged so that its axis is substantially coincident with the longitudinal axis of said through-cavity.

Furthermore, in a further embodiment of the invention, the dissipating means comprise at least one closed circuit and at least one pump for circulating a coolant in said closed circuit. This closed circuit is at least partially arranged in said at least one central portion next to the face contacting said electronic board, so that said coolant absorbs at least partially the heat absorbed by said at least one central portion. In particular, said closed circuit is made between the face contacting the electronic board and the through-cavity.

Furthermore, said at least one circuit comprises a delivery duct and at least one suction duct, wherein said at least one delivery duct and/or said at least one suction duct are made, at least partially, in said central portion. Thanks to this solution, the most part of this circuit can be easily made in the central body, i.e. without adding further components to the lamp.

Advantageously, the central portion as well as said at least one through-cavity have substantially cylindrical shape. Moreover, said central portion comprises connecting means to connect said central portion with said at least one duct a coolant can cross, so that said duct is fluidically connected to said at least one through-cavity. In particular, this fluidic connection is of sealed type.

In other embodiments, the central portion as well as said at least one through-cavity have substantially polygonal cross section. Again, said central portion comprises connecting means to connect said central portion with said at least one duct a coolant can cross, so that said duct is fluidically connected to said at least one through-cavity. In particular, this fluidic connection is of sealed type.

This connecting duct can have cylindrical shape or polygonal cross section depending on the shape taken by said through-cavity.

Finally, thanks to the invention, an air-conditioned environment is provided, such as for example a greenhouse, comprising at least one lamp according to at least claim 11 or 12, and at least one air conditioning system having at least one ejection/reintroduction duct for ejecting and/or reintroducing air from/into said air- conditioned environment and at least one fan for suctioning air along said at least one ejection and/or reintroduction duct, wherein said at least one lamp is constrained to said at least one duct of said air conditioning system through said connecting means. Moreover, this air-conditioned environment comprises at least one switch for switching on said at least one LED lamp, wherein said at least one switch is functionally connected to said at least one fan of said conditioning system so as to control the activation of said at least one fan simultaneously with the activation of said at least one lamp.

Finally, said air conditioning system comprises at least one flow diverter arranged upstream of said at least one lamp, along said at least one air ejection/reintroduction duct from/into said air-conditioned environment, and one control unit provided with one or more monitoring sensors to monitor the climatic conditions of said air- conditioned environment, wherein said at least one flow diverter is adapted to divert the air flow crossing said at least one duct so as to eject and/or reintroduce it, at least partially, into said air-conditioned environment depending on data detected by said one or more monitoring sensors.

According to a further embodiment of the invention, an additional air-conditioned environment is also provided, for example a greenhouse, comprising at least one lamp according to at least claim 11 or 12.

In particular, this air-conditioned environment comprises at least one lamp according to at least claim 11 or 12, and at least one air conditioning system having at least one diffusion duct to diffuse the treated air in said air-conditioned environment and at least one closed heating circuit for treating said air and in which a working fluid circulates, said heating circuit comprising said at least one lamp and at least one pump for pushing said working fluid within said circuit through said at least one through-cavity of said at least one lamp, said heating circuit further comprising at least one inlet and/or outlet duct of said working fluid into/from said at least one lamp, wherein said at least one lamp is constrained to said at least one inlet and/or outlet duct by said connecting means.

Still according to this embodiment, said heating circuit comprises at least one radiator external to said at least one environment, at least one heat exchanger for said working fluid functionally combined with said air diffusion duct for the controlled heating/cooling of said air, and means for controlling the passage of said working fluid between said inner radiator and said heat exchanger for said working liquid.

Moreover, said control means comprise at least one first three-way valve and at least one second three-way valve, wherein said first three-way valve directs, by control, said working fluid coming from said through-cavity of said at least one lamp at the direction either of said at least one external radiator or said at least one heat exchanger for said working fluid, and said second three-way valve directs, by control, said working fluid coming either from said external radiator or said heat exchanger for said working fluid at the direction of said through-cavity of said at least one lamp.

Finally, such air-conditioned environment comprises a control unit for said control means and at least one temperature sensor arranged in said air-conditioned environment and functionally connected to said control unit, said control unit controlling the operation of both said at least one first three-way valve and said at least one second three-way valve depending on the temperature measured by said at least one temperature sensor, in order to follow the temperature set in said air-conditioned environment.

Brief description of the drawings

Further aspects and advantages of the present invention will be more evident from the following description made for illustration purposes only and without limitation, referring to the accompanying schematic drawings, in which:

figure 1 shows a schematic side view of a LED lamp of known art; figures 2A and 2B respectively show side and front views of a first embodiment of the lamp according to the invention;

figure 3 A shows a front view of a second embodiment of the invention; figure 3B shows a top view of the embodiment of figure 3 A;

figures 4A and 4B respectively show side and front views of a third embodiment of the lamp according to the invention;

figure 5 shows a greenhouse comprising a lamp according to the invention;

Figure 6 shows an air-conditioned environment, according to a further embodiment, comprising a lamp according to the invention. Embodiments of the invention

Referring to the attached figures, some possible embodiments of the LED lamp 1 according to the invention will now be described. It should be noted that in the embodiments described hereafter, identical elements of the lamp 1 have identical numerical or alphanumerical references.

Figure 1 shows a LED-type lamp 150 of known art. In particular, this LED power lamp 150 comprises a light source 200 provided with an electronic board 200a having a plurality of light-emitting diodes 200b, of the "led-chip" type as mentioned above, and dissipating means 300 to dissipate the heat produced by the light source 200. Such dissipating means 300 comprise a dissipator 400 provided with a central portion 400a having a face 400c arranged to directly contact the electronic board 200a and a finned portion 400b to disperse the heat absorbed by the central portion 400a during the operation of the light source 200. The fins of the finned portion 400b are arranged along the Z direction, substantially orthogonal to the substantially planar electronic board 200a. Furthermore, this known art LED lamp 150 also includes a cooling fan 500 for directing an air flow through the finned portion 400b. As evident from figure, if the lamp 150 is placed in environments where there is high concentration of dust, the fins 400b would be the ideal settling surface for such dust and, therefore, the efficiency of the dissipating means 300 would be quickly reduced possibly resulting in negative effects also for the operation of the lamp 150 itself.

As shown in figures 2A and 2B, the lamp 1 according to the invention comprises two light sources 2, each provided with an electronic board 2a comprising a plurality of light-emitting diodes 2b of the "led-chip" type, and dissipating means 3 to dissipate the heat produced by each light source 2. Such dissipating means 3 comprise a dissipator 4 provided with a central portion 4a, having a face 4b directly contacting the two electronic boards 2a and a first finned portion 4c to disperse the heat absorbed by the central portion 4a during the operation of the two light sources 2, and cooling means 5 to route an air flow through the first finned portion 4c. In particular, according to the embodiment shown herein, the cooling means 5 comprise a fan. Each light source 2 further comprises a reflector 60 and an optical lens 61 combined with the reflector 60 for diffusing the light emitted by the light emitting diodes 2b integrated in the electronic board 2a.

Advantageously, the central portion 4a comprises a section bar provided with a through-cavity 6 having longitudinal axis L substantially parallel to the plane P on which the two electronic boards 2a lie. Furthermore, the first finned portion 4c extends over part of the inner side 6a of the through-cavity 6. In the embodiment shown herein, the through-cavity 6 has substantially rectangular cross-section, therefore having four inner sides 6a; the first finned portion 4c extends from three of said four inner sides 6 towards the center of the through-cavity 6 and along the longitudinal axis L of the through-cavity 6 itself.

According to this embodiment, the cooling means 5 comprise, as above mentioned, a fan 5 arranged so that its axis V is substantially coincident with the longitudinal axis L of the through-cavity 6. The fan 5 is arranged in the through-cavity 6 so as to reduce the longitudinal dimension of the lamp 1. In particular, according to the embodiment described herein, the fan 5 is arranged at one of the ends 6b of the through-cavity 6, inside the through-cavity 6 itself. In other embodiments not shown herein, the fan 5 could also be placed outside the through-cavity 6, although this leads to increased longitudinal dimensions of the lamp 1.

In the embodiment of figure 3A, the lamp 1 further comprises also a second finned portion 4d extending from the outer side 4e of the central portion 4a. In particular, this second finned portion 4d extends from two opposing outer sides 4e of the central portion 4a such that each fin of such second finned portion 4d is parallel to the plane on which the electronic board 2a of each light source 2 lies.

Still according to this further embodiment of the invention shown in figure 3 A and in figure 3B, the dissipating means 3 further comprise also a closed circuit 10 and a pump 11 for circulating a coolant in the closed circuit 10. The closed circuit 10 is made, partially, in the central portion 4a, next to the face 4b contacting the electronic board 2a, such that the coolant, which generally comprises distilled water and additives or, in others embodiments, other combinations of substances typically used in this context, absorbs as much as possible part of the heat absorbed also by the central portion 4a. In particular, the closed circuit 10 comprises a delivery duct 20 and a suction duct 21, in which such delivery duct 20 and such suction duct are partially made in the central portion 4a. As can be seen in figure 3 A and partially in figure 3B, the closed circuit 10 is arranged between the through-cavity 6 and the two electronic boards 2a of each light source 2. In this way the cooling efficiency of the dissipating means 3 can be considerably increased.

According to an alternative embodiment shown in figures 4 A and 4B, the lamp 1 comprises two light sources 2, each provided with an electronic board 2a having a plurality of light-emitting diodes 2b, of the type already denoted above as "led chip". Moreover, also in this case, the central portion 4a has a face 4b directly contacting the two electronic boards 2a and a first finned portion 4c for dispersing the heat absorbed by the central portion 4a during the operation of the two light sources 2. Advantageously, unlike the embodiments described above, the central portion 4a, having a substantially cylindrical shape, comprises a section bar provided with a through-cavity 6 having longitudinal axis L substantially parallel to the plane P on which the two electronic boards 2a lie. The first finned portion 4c extends over the inner side 6a of the through-cavity 6. In the embodiment shown herein, the through- cavity 6 has substantially circular cross-section, therefore it has an inner cylindrical surface 6a the first finned portion 4c inwardly extends therefrom. In particular, such first finned portion 4c comprises a series of fins 44 having directions parallel to each other, wherein each fin 44 joins two points of the inner surface 6a to the cylindrical through-cavity 6. In practice, each fin 44 is a sort of chord of the circular section of the through-cavity 6.

According to this embodiment, the central portion 4a further comprises connecting means 40 to connect the central portion 4a to two ducts 121 (see in particular figure 5 and the corresponding embodiment described hereinafter), crossed by a coolant such as air or another fluid such as for example water (see figure 6 and related embodiment), such that the ducts 121 are sealingly and fluidically connected to the cylindrical through-cavity 6. These constraining means 40 comprise two sleeves longitudinally extending from the ends 4f of the central portion 4a itself. Each sleeve 40 has a cylindrical inner surface 40a flush with the inner cylindrical surface 6a of the through- cavity 6 and a cylindrical outer surface 40b flush with the inner surface (not shown here) of the respective duct 121 to which it is connected. In this way the sleeves 40 can be inserted by translation into the circular section of the respective duct 121. It should be noted that, as shown in the embodiment described herein, the sleeves 40 may be made in one piece with the central portion 4a, or in other embodiments not described herein they may also be separate from the central body 4a and adapted to be connected to the relative through-cavity 6.

It should be noted that, although in the embodiment described in figures 4A and 4B the dissipating means 3 do not comprise any closed circuit 10 as conversely shown in the embodiment of figure 3, however a variant of this embodiment in which the dissipating means 3 also comprise this closed circuit 10, would still fall within the protection scope of the present invention.

It should also be added that in other embodiments not shown herein, the central portion 4a, as well as the through-cavity 6, may also be shaped with a substantially polygonal cross-section, for example with a rectangular cross-section (for example a rectangular cross-section), without thereby departing from the protection scope of the present invention. In this case, each sleeve 40 has a corresponding shape with polygonal cross- section or, in this case in particular, a rectangular cross-section, and has a rectangular- cross-section inner surface 40a flush with the inner surface 6a of the through-cavity 6 and a rectangular-cross-section outer surface 40b flush with the inner surface (not shown herein) of the respective duct 121 to which it is connected. In this way the sleeves 40 can be inserted into the circular section of the respective duct 121, by translating them. It should be noted that, in further embodiments, the central portion 4a and the portion of the through-cavity 6 may have, respectively, circular and polygonal cross-sections, or vice versa, without thereby departing from the protection scope of the present invention.

Figure 5 shows an air-conditioned environment 100 such as, for example, an agricultural greenhouse, which comprises a lamp 1 with the embodiment described in Figures 4 A and 4B, and an air conditioning system 120 having two ducts 121 for ejecting and/or reintroducing air from/into the air-conditioned environment 100 and a fan 122 to carry air along the two ejection and/or reintroduction ducts 121 for ejecting and/or reintroducing air outside and/or inside the air-conditioned environment 100. As shown in figure 5, the lamp 1 is constrained to the two ducts 121. This is achieved by virtue of the aforementioned constraining means 40 which comprise two sleeves longitudinally extending from the ends 4f of the central portion 4a itself. Each sleeve 40 has a cylindrical inner surface 40a flush with the inner cylindrical surface 6a of the through-cavity 6 and a cylindrical outer surface 40b flush with the inner surface (not shown) of the respective duct 121 which the sleeve 40 is combined with. In this way the sleeves 40 can be inserted by translation into the circular section of each air- ejection duct 21. Therefore, this solution not only prevents the first finned portion 4c from coming into contact with the dust found in the temperature-regulated environment 100, but also prevents the need of a fan ad hoc for the operation of the lamp 1, thereby reducing the complexity of the lamp 1 itself.

The agricultural greenhouse 100 further comprises a switch 123 for switching on the lamp 1. In particular, such switch 123 is functionally connected to the fan 122 of the air conditioning system 120 so as to control the activation of the fan 122 when also the lamp 1 is switched on.

Clearly, such a solution does not require to provide a further fan within the lamp 1 and, therefore, allows the exploitation of the temperature of the air which is released from the greenhouse 100. Therefore, this reduces not only the number of the components of the lamp 1 but also the power consumption of the lamp 1 itself, as well as that of the temperature-regulated, i.e. air-conditioned, environment 100.

This solution may be absent if the operation of the lamp 1 is prearranged to operate with no interruptions during the day.

Still according to the invention, according to the embodiment described above, the conditioning system 120 also comprises a flow diverter 130 such as, for example, a three-way throttle valve arranged upstream of the lamp 1 , along one of the two ejection and/or reintroduction ducts 121 for ejecting and/or reintroducing air from/into said air- conditioned environment 100, and a control unit 131 provided with three sensors 132 for monitoring the climatic conditions of said air-conditioned environment.

In particular these sensors 132 are, respectively, temperature, humidity and C0 ₂ sensors. In other embodiments the number of sensors 132 can also vary without departing from the protection scope of the present invention.

The flow diverter 130 is adapted to divert the air flow crossing the ducts 121 in such a way as to at least partially eject and or reintroduce it from/into the air-conditioned environment 100 depending on the data detected by the three sensors 132.

Unlike the case shown above, in which the lamp 1 directly heats the air introduced into or released from the air-conditioned environment 100, figure 6 shows a further embodiment of an air-conditioned environment 100 such as, for example, an agricultural greenhouse, in which one or more lamps 1 heat up a working fluid (and thereby are cooled by the latter) which, in turn, heats up the air entering the air- conditioned environment 100. The air-conditioned environment 100 of Figure 6 comprises, in particular, five lamps 1 of the type described, for example, in Figures 4A and 4B. This environment 100 comprises an air conditioning system 600, whose components are well known to the field technician and therefore neither shown nor described in detail hereinafter, the air conditioning system also having a diffusing duct 700 to diffuse the air treated in the air-conditioned environment 100 and a heating circuit 601 for the air treatment. A working fluid, such as water, circulates in the heating circuit 601. This closed heating circuit 601 comprises the aforementioned five lamps 1 and a pump 602 for pushing the water into the heating circuit 601 and through the through-cavity 6 of each lamp 1. This heating circuit 601 further comprises an inlet duct 121a for the working fluid to enter the lamps 1 and an outlet duct 121b to release such working fluid from the lamps 1. The lamps 1 are also constrained to the inlet and outlet ducts 121a and 121b by the connecting means 40 described above and having identical shape.

Furthermore, the heating circuit 601 further comprises an external radiator 604 outside the environment 100, a heat exchanger 605 for the working fluid to exchange heat with treated air and functionally combined with the diffusing duct 700 for the controlled heating of air, and means 606 to control the passage of the working fluid between the external radiator 604 and the heat exchanger 605.

These control means 606 comprise at least one first three-way valve 607 and one second three-way valve 608, wherein the first three-way valve 607 directs, by control, the working fluid coming from the through-cavities 6 of each lamp 1 at the direction either of the external radiator 604 or the heat exchanger 605 for the working fluid, and the second three-way valve 608 directs, by control, the working fluid coming either from the external radiator 604 or the heat exchanger 605 for the working fluid, at the direction of the through-cavities 6 of the lamps 1. In practice, if the air crossing the diffusing duct 700 has to be heated, then the first three-way valve 607 and the second three-way valve 608 will direct the fluid in such a way as to pass only through the heat exchanger 605, thus bypassing the external radiator 605 whereas on the contrary, in the case where the air entering the environment 100 has to be cooled, then the first three-way valve 607 and the second three-way valve 608 will direct the fluid in such a way as to cross only the external radiator 604, thus bypassing the passage through the heat exchanger 605.

Finally, the air-conditioned environment 100 comprises a control unit 800 for the control means 606 and at least one temperature sensor 801 in the air-conditioned environment 100 and functionally connected to the control unit 800. This control unit 800 thus control the operation of the first three-way valve 607 and the second three- way valve 608 based on the temperature measured by the temperature sensor 801 so as to follow the temperature set by the user in the air-conditioned environment 100.