Abstract:
A device redistributes light emitted by one or more LEDs and constitutes a secondary optical component for the construction of sources, lamps, illuminating bodies, and solid state optical signaling apparatuses. In one of its basic forms the device comprises a main optical element and an optical protection case coupled by a pin, with the optical element being disposed in a cavity of the protection case.

Description:
FIELD OF THE INVENTION 
     The present invention relates to a device for redirecting the luminous flow emitted by one or more LEDs as a secondary optical component for the construction of sources, lamps, illuminating bodies and solid state optical signaling apparatuses. 
     The object of the present invention is to obtain with the lowest possible fabrication costs with respect to what is known in the prior art and available commercially a device for redistributing the luminous flow emitted by one or more LEDs in such a way that the optical axis is rotated by 90° and at the same time the emission angles can be varied relative to said axis. 
     DESCRIPTION OF RELATED ART 
     In the most general form, all current devices for redistributing the luminous flow with rotation of the optical axis to 90° for LED emitters provide for the use of conical solid structures with the vertex reversed and oriented towards the upper part of the primary lenses integral with the LED emitters. 
     An additional characterization of the devices currently in use is that their conical shape is typically supported by a hollow cylindrical structure within which are located the LEDs and which is fastened to the outer edge of said emitter or to the surface/structure whereon they are positioned. 
     Further variants of the devices currently in use provide for the use or the modification of primary lenses so that at the top of the standard convex shape of the surface of said lenses is obtained a depression with a conical shape with the vertex towards the junction to the semiconductor emitter of the luminous flow. 
     SUMMARY OF THE INVENTION 
     The main object of the present invention is to provide superior functional performance with respect to the prior art in relation to the capability of defining differently the angles of emission above and below the optical axis rotated by 90° with respect to that of the LED emitters and at the same time obtaining a greater intensity of emission due to the mutually combined functionalities of optical reflection and refraction. 
     Because it has no direct connection to the LEDs, a further advantage of the invention is that it can be inserted within optical protection cases typically in use in lamps and thereby allow their easy replacement, if required for maintenance reasons or because of changed requirements of the redistribution of the luminous flow, by virtue of the connection by conical insertion or in snap-in fashion. 
     These objects and advantages are all achieved by the invention in question as it is characterized by the appended claims. 
     Additional characteristics and advantages of the present invention will become more readily apparent from the following detailed description of preferred, but not exclusive, embodiments of the invention, all based on the same principle and illustrated purely by way of non limiting example in the accompanying figures, in which: 
    
    
     
       DETAILED DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows the section view of the invention comprising the set of its elements among which the optical protection case (where for the sake of illustration clarity the usual dashed lines are omitted) coupled onto a characteristic solid state source shown in a lateral view; 
         FIG. 2  shows a variant of the invention shown in the same way as  FIG. 1  and characterized by an additional reflecting/diffusing element and by an additional spacer element; 
         FIG. 3  shows an additional variant of the invention shown in the same way as  FIG. 2  and characterized by an additional element for connecting to the optical protection case; 
         FIG. 4  shows the invention of  FIG. 1  in which with dashed lines are shown the modifications made to the distribution of the main luminous flow produced by the LED emitters. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     With reference to the aforementioned figures, the numeral  1  indicates the main optical element of invention,  20  the optical protection case,  40  an optional reflector/diffuser,  50  an optional spacer element,  60  an alternative separate connection element,  30  a typical commercial solid state source. 
     With reference to  FIG. 1 , the conformation of the main optical element  1 , preferably but not exclusively made of optical grade polycarbonate, for the purposes of redistributing the luminous flow according to what is described above and shown in  FIG. 4  with the reference number  100  is achieved by: 
     a profile indicated by the number  2  that inferiorly by revolution around the axis of symmetry defines a surface characterizing a conical cavity with the vertex positioned in opposite direction relative to the primary lenses of the LEDs indicated by the number  34  (unlike what is found in products currently available on the market and according to the prior art),
 
a profile indicated by the number  4  that superiorly by revolution around the axis of symmetry defines a surface characterizing a cupola-shaped cavity with the vertex positioned in the direction of the primary lenses of the LEDs indicated with the number  34 ;
 
a profile indicated by the number  3  that laterally by revolution around the axis of symmetry defines a surface characterizing a cone frustum shaped solid with the vertex positioned in the direction of the primary lenses of the LEDs indicated by the number  34 .
 
     With reference to  FIG. 1 , the number  5  indicates a cylindrical pin preferably with slight conicity obtained as an appendage of the element  1 . 
     With reference to  FIG. 1 , the number  21  indicates a cylindrical cavity, preferably with slight conicity located inside the thickened region  23  of the optical protection case  20  to house the pin  5  and achieve the mechanical coupling between the elements  20  and  1 . 
     In relation to the optical protection case  20  of  FIG. 1 , preferably but not exclusively made of optical grade polycarbonate, the thickened region at the top  23  has an inner surface  22  that is convex towards the inner cavity  24 . Said convex surface  22  is preferably made in such a way as to obtained a diffuse reflection. 
     With reference to  FIG. 1 , the number  33  indicates the edge for fastening, in snap-in fashion or by screw or with other means, the commercial solid state source  30  with the elements  20  and  1  previously coupled to each other by insertion in the hollow region  24 . 
     Also with reference to  FIG. 1 , the commercial solid state source  30  may also be of the type lacking the adapter ring  32  and constituted by the sole electrical attachment  31  comprehensive of the electrical/electronic circuits for controlling the current to the LED emitters  34 . This possibility, not shown in the figures, entails that the edge of the electrical attachment serves the same function as the edge  33  of the adapter ring  32  for the purposes of fastening, in snap-in or screw-in fashion, or by other means, to the optical elements  20  and  1 . 
     With reference to  FIG. 2 , as an embodiment variant of the invention indicated in  FIG. 1 , the reference  40  indicates a reflector/diffuser element having a convex surface  41  of the specular reflecting or diffuse reflecting type. 
     The element  40 , made of metallic or plastic material with an added metal-coating, will be positioned by the element  1  at a distance predetermined by means of a spacer element  50 . 
     In an additional embodiment, not shown, the spacer element  50  may be obtained as an appendage of the reflector/diffuser element  40  or alternatively to the main optical element  1 . 
     With reference to  FIG. 2 , the remaining elements shown serve the same purpose indicated for the those of  FIG. 1 , whereto the reader is referred for their description. 
     With reference to  FIG. 3 , as an additional embodiment of the invention of  FIG. 2 , the number  6  indicates a hole at the centre of the main optical element  1  instead of the cylindrical pin  5  into which is inserted, during the coupling with the optical protection case  20 , a preferably metallic pin  60 , with its surface preferably nickel- or chrome-plated, provided with retaining head  61  to reduce the slight luminous flow dispersed in the direction of the optical axis of the LEDs  34 . 
     With reference to  FIG. 3 , the remaining elements shown serve the same function indicated for those of  FIG. 2 , whereto the reader is referred for their description. 
     It is specified that in accordance with the teachings provided by the present description, the surfaces of the optical elements can be subject to numerous dimensional variations in the geometry of the profiles indicated with the numbers  4 ,  3 ,  2 ,  22 ,  41  for the purposes of modifying the upper and lower angles of redistribution of the luminous flow with axis of 90° relative to that of the LEDs  34 , in order to meet the different application requirements. 
     Moreover, it is stressed that the invention and its described variants may be subject to numerous changes of a practical-application nature of the constructive details (among them, materials used and systems for interconnecting the elements) without thereby departing from the scope of the inventive idea as claimed below.