Patent Publication Number: US-8979323-B2

Title: Led lighting device having light emitting and power circuitry integrated within a casing

Description:
The present invention relates to a LED lighting device. 
     BACKGROUND OF THE INVENTION 
     It is known that LED lighting sources are increasingly common in the lighting sector. However, the use of LEDs still displays some drawbacks that the known lighting devices have not yet completely solved. 
     For example, if making of relatively small lighting apparatuses with high lighting capacity is desired, an adequate number of lighting sources and an adequate space for installing the supply and control assembly of the sources must be provided. It is not thus possible, in general, to make particularly compact apparatuses, e.g. very thin ones, unless the supply and control assembly is housed outside the apparatus. 
     On the other hand, in the lighting sector, the search for technical solutions which also allow to obtain new concept lighting effects is constant, being in this sector fundamental not only the solely functional aspect but also the aesthetic and emotional component. 
     Ultimately, the known devices appear improvable, particularly in terms of construction simplicity, efficiency, dimensions, and versatility (i.e. capacity of providing original lighting effects). 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a LED lighting device which is, with respect to the known solutions, at least equally or more efficient, simple and versatile, as well as capable of providing particular lighting effects, being further extremely compact. 
     The present invention thus relates to a LED lighting device as disclosed in essential terms in the accompanying claim  1  and in the additional features thereof which are disclosed in the dependent claims. 
     The device of the invention is simple to make and install, fully efficient, reliable and very versatile, allowing to obtain particular lighting effects; the apparatus of the invention may further have a very small size while housing the electric and electronic supply and control components of the LEDs inside. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further features and advantages of the present in invention will be apparent in the description of the following non-limitative examples of embodiment, with reference to the accompanying drawings, in which 
         FIG. 1  is a perspective, diagrammatic view of a LED lighting device in accordance with the invention; 
         FIG. 2  is a partially exploded, diagrammatic view with parts removed for clarity of the device in  FIG. 1 ; 
         FIG. 3  is a partially exploded, diagrammatic longitudinal section view with parts removed for clarity of the device in  FIG. 1 ; 
         FIG. 4  is a diagrammatic view of an inner detail of the device in  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     With reference to the accompanying figures, a LED lighting device  1  comprises a casing  2 , a plurality of power LEDs  3  fixed to a LED-carrier plate  4 , and a plurality of optical elements  5  arranged facing respective LEDs  3 . 
     The casing  2  extends substantially along an axis A and is formed by two half-shells  6 ,  7  joined to one another on opposite sides of axis A and internally defining a chamber  8  inside the casing  2 , in which the board  4 , the LEDs  3  and the optical elements  5  are housed. 
     A first half-shell  6  is made of light permeable material and/or comprises at least one front wall  9 , facing the LEDs  3  and which covers or surrounds the optical elements  5  and constitutes a light emission plate  10 , made of light permeable material. 
     In the preferred embodiment shown, the half-shell  6  is substantially C-shaped having a cross section orthogonal to axis A, C-shaped; the half-shell  6  further comprises, in addition to the front wall  9 , a pair of facing and parallel sides  11 , which extend from respective sides opposite to the front wall  9  and are substantially orthogonal to the front wall  9 . 
     The second half-shell  7  is made of heat conductive, light impermeable material and/or comprises at least one rear wall  12 , facing the front wall  9  of the half-shell  6 , made of heat conductive, light impermeable material. 
     In the preferred embodiment shown, the half-shell  7  is also substantially C-shaped; the half-shell  7  has a longitudinal section parallel to axis A, C-shaped; the half-shell  7  comprises, in addition to the rear wall  12 , a pair of sides  13  facing and parallel, which extend from respective side edges opposite to the rear wall  12  and are substantially orthogonal to the rear wall  12 . 
     The board  4  is arranged on an inner face  16 , facing the chamber  8  and the front wall  9 , of the rear wall  12 ; the rear wall  12  constitutes a heat dissipation plate  17  opposite to the light emission plate  10 . 
     Advantageously, the first half-shell  6  is made of polymeric material and the second half-shell  7  is made of aluminum; or, the second half-shell  7  or at least the rear wall  12  thereof, are made of ceramic material. 
     The sides  11 ,  13  of each of the half-shells  6 ,  7  are substantially orthogonal to the sides of the other half-shell and are inserted between the sides of the other half-shell. 
     The two half-shells  6 ,  7  are joined to form the casing  2  along respective peripheral edges. 
     The two half-shells  6 ,  7  are joined to each other mechanically, e.g. by means of screws or other fastening elements, or in other known manner, e.g. welded, glued etc. 
     The board  4  is applied directly onto the inner face  16  of the heat dissipation plate  17 , i.e. onto the rear wall  12 , facing the light emitting plate  10 . 
     The optical elements  5  are, for example (but not necessarily), total internal reflection lenses; each optical element  5  has an optical body  20 , which extends along and about an optical axis A between two opposite axial ends provided, respectively, with an inlet surface  21 , facing a LED  3 , and an outlet surface  22 , either facing the light emission plate  10  or inserted therein. The optical axes A are parallel to one another and substantially perpendicular to the light emission plate  10 . 
     The side wall  12  constitutes the heat dissipation plate  17  on which the board  4  is directly applied as indicated, made of heat conductive material, e.g. aluminum or ceramic material, so as to effectively dispose the heat generated by the LEDs  3  outside the casing  2 , without requiring further dissipation structures. 
     Being made of light permeable (transparent, translucid etc.) material, the half-shell  6  and specifically at least the light emission plate  10  light up when the device  1  is on, collecting the light dispersed by the chamber  8  inside the casing  2 . 
     The device  1  thus provides a lighting effect in which the bright lighting beams exit from the outlet surfaces  22  of the optical elements  5 , while the rest of the light emission plate  10  is more weakly illuminated. 
     Advantageously, the light emission plate  10  is shaped so as to directly support the optical elements  5  and centre each of the optical elements  5  with respect to a LED  3 . 
     In particular, as shown in  FIG. 3 , the light emission plate  10  has seats  23  engaged by respective optical elements  5 ; the optical elements  5  are mechanically coupled to the seats  23 , e.g. by means of fastening elements  24 ; each optical element  5  is mechanically coupled to a seat  23 , preferably in releasable manner, by means of fastening elements  24  shaped directly on the optical body  20  and on the light emission plate  10  and cooperating with one another. 
     The LEDs  3  are advantageously housed in respective recesses  25  of the optical elements  5 . 
     The light emission plate  10  may have through holes aligned to respective optical elements  5 , and through which the optical elements  5  are insertable in the seats  23  and possibly replaceable after releasing the fastening elements  24 ; or, the emission plate  10  may have a substantially flat, continuous outer surface which covers the optical elements  5 . 
     To increase the amount of light which illuminates the light emission plate  10 , gaps  29  from which the light exits are provided between a LED  3  and the optical element  5  associated thereto and/or between the optical elements  5  and the light emission plate  10 . 
     With particular reference to  FIG. 4 , the casing  2  also houses a power supply-transformer  30 , connectable to an external supply network and adapted to transform the network voltage into a supply voltage for LEDs  3  (typically by reducing the network voltage, 220/230 V, low voltage, 12/24/etc. V); the power supply-transformer  30  is formed by a group of electric and/or electronic components  31  entirely housed in the chamber  8  within the casing  2 ; at least one of the components  31  of the power supply-transformer  30  are arranged on the board  4 , between the LEDs  3  and the optical elements  5 . 
     The LEDs  3  are connected by conductor tracks  32  (only diagrammatically and practically shown in  FIG. 4 ) arranged (e.g. printed) on the board  4 ; the traces  32  are included in a circuit  33  (preferably a printed circuit) which connects the LEDs  3  and the components  31  of the power supply/transformer  30 . 
     By distributing the components  31  of the power supply-transformer  30  also in the available space on the board  4  between the LEDs  3  and between the optical elements  5 , the size of the casing  2  needed to house the entire power supply-transformer  30 , and thus the overall dimensions of the device  1 , is reduced. 
     The small size of the device  1  makes it particularly versatile. 
     In the non-limiting example in  FIG. 1 , for example, the device  1  is provided with a supporting element  40  and an articulated mechanism  41  which connects the casing  2  to the supporting element  40 . The supporting element  40  is housed in a channel  42 , formed, for example, by a profile  43 , and slides along a guide  44  within the channel  42 . 
     The mechanism  41  is shaped so as to allow the rotation of the casing  2  with respect to the supporting element  40  about at least two rotation axes and preferably about three rotation axes orthogonal to one another. 
     For example, the mechanism  41  comprises a pair of pins  45 , fixed respectively to the supporting element  40  and to the casing  2  and hinged to one another by means of a joint  46 ; each pin  45  extends along a rotation axis X and is rotational with respect to the joint  46 , independently from the other pin  45 , about such axis of rotation X; the joint  46  further allows the two pins  45  to turn with respect to one another about a third axis of rotation Z perpendicular to the rotation axes X. 
     The small size and the presence of the mechanism  41  allow position and orientation of the casing  2  to be changed and also the casing  2  to be concealed inside the channel  42 . 
     It is in all cases understood that the device  1 , possibly provided with another suitable supporting element and/or different jointing mechanism, may be used to make other types of lamps (e.g. wall, table, floor lights etc.). 
     Moreover, it is understood that further changes and variations can be made to the lighting device described and shown herein without departing from the scope of protection of the appended claims.