DEVICE FOR REDIRECTING THE LUMINOUS FLUX EMITTED BY ONE OR MORE LED

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The present invention relates to a device for redirecting the Iu- minous flow emitted by one or more LEDs as a secondary optical component for the construction of sources, lamps, illuminating bodies and solid state optical signalling 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 90and at the same time the emission angles can be varied relative to said axis.

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 vertex reversed and oriented towards the upper part of the primary lenses integral with the LED emitters.

An additional characterisation 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 conical shape with vertex towards the junction to semiconductor emitter of the luminous flow.

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 also 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 of obtaining a greater intensity of emission due to the mutually combined functionalities of optical reflection and refraction.

A further advantage of the invention, since it has no direct con- nection to the LEDs is that it can be inserted within optical protection cases typically in use in lamps and thereby to 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 characterised 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:

Figure 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) cou- pled onto a characteristic solid state source shown in a lateral view;

Figure 2 shows a variant of the invention shown in the same way as figure 1 and characterised by an additional reflecting/diffusing element and by an additional spacer element; Figure 3 shows an additional variant of the invention shown in the same way as figure 2 and characterised by an additional element for connecting to the optical protection case;

Figure 4 shows the invention of figure 1 in which with dashed lines are shown the modifications made to the distribution of the main lumi- nous flow produced by the LED emitters.

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 figure 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 figure 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 characterising 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 characterising 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 characterising 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 figure 1 , the number 5 indicates a cylindrical pin preferably with slight conicity obtained as an appendage of the element 1.

With reference to figure 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 figure 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 figure 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 figure 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 figure 2, as an embodiment variant of the invention indicated in figure 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 added metal-coating, will be positioned by the element 1 at a distance predetermined by means of a spacer element 50.

In some additional embodiment, not shown, the spacer ele- ment 50 may be obtained as an appendage of the reflector/diffuser element 40 or alternatively to the main optical element 1.

With reference to figure 2, the remaining elements shown serve the same purpose indicated for the those of figure 1 , whereto the reader is referred for their description. With reference to figure 3, as an additional embodiment of the invention of figure 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 figure 3, the remaining elements shown serve the same function indicated for those of figure 2, whereto the reader is referred for their description.

It is specified that in accordance with the teachings provided by the present description, the definition of the surfaces of the optical elements will 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.