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DESCRIPTION

The present invention relates to an LED projector.

There exist sequences of light emitting diodes (LEDs) positioned inside lenses, arranged in turn in a line into a strip, as in CN201293226Y, or on a surface of a board to form a matrix, as in CN201964325U or CN201964326U.

Said strips of lenses for LEDs may also be positioned in parallel rows, as in patents US7118236B2 or TW201033523 A, where strips have a different orientation with respect to the plane to be illuminated, thus making assembly disadvantageously complicated.

Said lenses for LEDs may be symmetric, as in CN201964325U, or asymmetric, as in CN201964326U.

To illuminate a large area, a greater number of projectors must be costly used to obtain the required illumination effect.

There are no standards for making projectors, and thus replacing the single faulty elements becomes difficult.

It is an object of the present invention to provide a LED projector in which the shape of the light beam of the projector itself can be easily varied within a wide range of available photometric curves in order to vary both the beam directionality and the distribution of the light beam intensity on the plane as desired.

According to the invention, such an object is achieved by a LED projector according to claim 1.

These and other features of the present invention will become more apparent from the following detailed description of a practical embodiment thereof, shown by way of non- limitative example in the accompanying drawings, in which:

Figure 1 shows a perspective view of a LEDs projector; Figure 2 shows a second perspective view of the LEDs projector; Figure 3 shows a top plan view of the LEDs projector;

Figure 4 shows a perspective view of a reflective sheet of the LEDs projector;

Figure 5 shows a front view of the reflective sheet;

Figure 6 shows a top plan view of the reflective sheet;

Figure 7 shows a section taken along line VII- VII in figure 5;

Figure 8 shows a top plan view of a strip of lenses for an asymmetric LED configuration;

Figure 9 is a section view taken along line IX-IX in figure 8;

Figure 10 is a section view taken along line X-X in figure 8;

Figure 11 shows a bottom plan view of the strip of lenses in Figure 8;

Figure 12 shows a top perspective view of the strip of lenses in Figure

8;

Figure 13 shows a bottom perspective view of the strip of lenses in

Figure 11 ;

Figure 14 shows a top plan view of a strip of symmetric lenses;

Figure 15 shows a section view taken along line XV-XV in Figure 14; Figure 16 shows a section view taken along line XVI -XVI in Figure 14;

Figure 17 shows a top plan view of the strip of lenses in Figure 14; Figure 18 shows a bottom perspective view of the strip of lenses in Figure 14;

Figure 19 shows a bottom perspective view of the strip of lenses in Figure 17.

The above-listed figures, and Figure 2 in particular, show a LED projector 1 (the LEDs 3 not shown in the figures) comprising a body 10 which mates with a glass lid (not shown in the figures) for external protection.

Said body 10 comprises a horizontal support plane 1 1 on which a motherboard 12 is mounted. Said motherboard 12 is protected on the four sides by: two L-shaped side sheets 15, a front sheet 16 on the front side and a rear sheet 17 on the rear side of the projector 1 of LEDs 3.

A plurality of LEDs 3 arranged in rows in linear sequence to form a horizontal, flat matrix are mounted on the motherboard 12. Strips 2 of lenses 30 which are separably engageable on said motherboard 12 by means of a plurality of centering bushes 25 for screws are superimposed on each of said rows of LED 3 of said matrix. Said strips 2 of lenses 30 are parallel to the greater sides thereof which identify a longitudinal axis L towards the greater side of the strip 2 of lenses 30, as shown in Figure 3.

A plurality of said strips 2 of lenses 30 parallel to one another identify a matrix 22 of lenses 30 on the motherboard 12. Said matrix 22 of lenses 30 on the motherboard 12 is horizontal and planar because it is mounted on the support plane 11 of the body 10 of the projector 1 with LEDs 3.

Each of said lenses 30 on the strip 2 of lenses 30 is arranged in linear sequence over and in correspondence of said LEDs 3.

Said lenses 30 act as diffusers and directors of the light of LEDs 3.

Said lenses 30 are expected to have either an asymmetric section 35, as shown in Figure 10, or a symmetric section 36, as shown in Figure 16.

A sheet 4, which is vertical with respect to the support plane 1 1 , is provided on each of said strips 2 of lenses 30, and said sheet 4 is arranged along the longitudinal axis L following the whole length of the strip 2 of lenses 30, as shown in Figures 2 and 3. Therefore, said sheets 4 extend upwards with respect to a horizontal plane identified by the matrix 22 of lenses 30, as shown in Figures 1-3. The upward direction with respect to a horizontal plane is intended when the projector 1 with LEDs 3 is positioned on a work top. When the projector 1 with LEDs 3 is mounted to operate, the upward direction substantially corresponds to the exiting direction of the light beam of the light of LEDs 3 as shown in Figures 1-3.

A connection 43, as shown in Figure 4, is provided at each of the two ends of said sheet 4, in order to fix sheet 4 to said support plane 11 by means of screws which are inserted into holes 44 of the connection 43 itself as shown in Figure 3.

The sheets 4 are engaged with screws on the support plane 11 independently of the strips 2 of lenses 30, fixed in turn with the other screws on the support plane 11.

Said sheet 4 provides a reflective surface 42 facing the front side of the projector 1 with LEDs 3 as shown in Figure 7, allowing to advantageously contribute to the directionality of the light of LEDs 3. Said reflective surface 42 increases the reflection of the light of LEDs 3 under the lenses 30 of the strip 2 of lenses 30, thus advantageously increasing the efficiency of the projector 1 with LEDs 3 without wasting energy.

Said strip 2 of lenses 30 comprises a plurality of housings 31 for LEDs 3, as shown in Figures 11 and 13. Said housings 31 are arranged in linear sequence along an axis S parallel to the longitudinal axis L, shifted with respect to the longitudinal axis L, in transversal direction towards the front of the projector 1 with LEDs 3, as shown in Figure 11.

Each of said housings 31 has an ellipsoidal shape and is adapted to cover an LED 3.

Each of said housings 31 is provided with a heat outlet 5 comprising two channels of different length: the short channel 51 towards the front side of strip 2 and the long channel 52 towards the rear side of strip 2, as shown in Figure 11. The short channel 51 and the long channel 52 have different lengths to advantageously promote the heat transmission and make ventilation even more effective. The heat flow is generated by the temperature difference between the higher temperature of the short channel 51 and the lower temperature of the long channel 52. Said heat outlets 5 advantageously minimize the sizes of the radiator elements of the prior art.

A number of notches 28 are provided on said strip 2 of lenses 30 to engage a side of said sheet 4 against an outer face of said lens 30, thus identifying a housing of the sheet 45 shown in Figures 10 and 16.

In order to illuminate a large surface as desired by the operator, by means of an appropriately shaped light beam, said projector 1 with LEDs 3 can be used, advantageously allowing to deform the light beam shape by means of the synergistic combination of said strips 2 of lenses 30 with asymmetric section with a combination of said strips 2 of lenses with symmetric section and along with the use of said sheets 4.

Furthermore, a configuration of strips 2 of lenses with asymmetric section for an entire matrix 22 of lenses 30, or a configuration of strips 2 of lenses 30 with symmetric section for an entire matrix 22 of lenses 30 can be used depending on the effects to be obtained on the illuminated surface.

Said LEDs 3 projector 1 advantageously allows to have a large number of photometric curves to vary both the beam directionality and the distribution of the light intensity of the beam over the illuminated surface as desired.

The enormous ease of assembly, reassembly and interchange between strips 2 allows to have a wide range of possible combinations by exchanging strips 2 of lenses 30 with asymmetric section and strips 2 of lenses 30 with symmetric section to create light beams of the shape desired by the operator.

A further advantage of said projector 1 with LEDs 3 allows to reduce the number of projectors 1 to illuminate a surface, because the beam of the single projector 1 with LEDs 3 may be fine-tuned to create appropriate interferences with other projectors within the illuminated surface.

Said sheet 4 may be inclined by a given angle with respect to an axis perpendicular to the horizontal plane identified by matrix 22.

Alternatively, the following options for the sheets 4 may be provided:

- sheet 4 may be made of mirror-like or matte, metallized metal material;

- sheet 4 may be directly made of mirror-like or matte aluminum;

- sheet 4 may be made of transparent thermoplastic material; - sheet 4 may be made of thermoplastic material, which is later metallized to obtain a mirror-like or matte finish;

- sheet 4 may be made of transparent thermoplastic material and directly obtained together with the layer 2 of lenses 30 (same mold, Fresnel reflection method).

It is worth noting that the reflection of the light of LEDs 3 on an opaque surface of sheets 4 depends on an incidence angle of the light beam of LEDs 3 with respect to a perpendicular line of an incidence plane of the opaque surface itself of sheet 4. Therefore, the light of LEDs 3 may also be angularly reflected by a sheet 4 of opaque material as contemplated in the alternatives above.