FR3133071A1 - Optical part with several serial output zones - Google Patents

Abstract

The invention relates to an optical part (200) comprising: - an input portion (220) capable of receiving light rays (210) coming from at least one light source (215); - an exit portion (230) capable of directing the light rays towards the outside of the optical part, the exit portion comprising at least one intermediate exit zone (231.1; 231.2; 231.3) and a final exit zone (232) ), The intermediate output zone comprises a first intermediate sub-zone (233.1; 233.2; 233.3) capable of directing part of the light rays coming from the light source towards the outside of the optical part, and a second intermediate sub-zone (234.1; 234.2; 234.3) capable of propagating part of the light rays coming from the light source inside the optical part towards another intermediate exit zone or towards the last exit zone. FIG. 2a

Description

Optical part with several output zones in series

The present invention relates to the field of optical parts capable of guiding light rays, for lighting or signaling devices, in particular for motor vehicles.

It is becoming more and more common to use semiconductor light sources, such as light-emitting diodes, LEDs, to perform different lighting functions, for example in automobile vehicles. The use of these small light sources with high brightness and reduced electrical consumption also makes it possible to produce original light contours in a compact system with reduced electrical energy.

The light functions performed by the lighting or signaling devices of a motor vehicle may include:

- lighting functions, generally incorporated in the front headlights of the vehicle for road lighting, or in the passenger compartment for lighting the interior of a vehicle, and

-signaling functions, which can be incorporated in the front and rear headlights of the vehicle or in the vehicle passenger compartment. The signaling functions may include the flashing function, or TI, for “Turn Indicator” in English, or even daytime running lights, or DRL, for “Daytime Running Light” in English.

The constraints generally associated with the realization of these lighting functions are as follows:

- space constraints, the space available in the passenger compartment or the headlights of the motor vehicle being very limited;

- cost constraint, leading to limiting the number of sources, or the number of printed circuits shared between LED type sources.

It is now required by car manufacturers to integrate increasingly complex lighting functions.

For this purpose, certain lighting or signaling devices use optical parts of the optical sheet type allowing personalized light renderings while limiting the number of sources and using an optical part of which one of the dimensions is reduced.

Patent application FR 2995969 A1 describes in particular an optical system with a guide sheet coupled to a light source. The guide sheet comprises two guide faces, including a rear face and a front face, to guide the light in a main guiding direction, and decoupling elements on the rear face to deflect part of the light rays towards the front face so that they come out of the tablecloth. The distribution of the decoupling elements along the sheet thus makes it possible to distribute the light rays coming from the sources in a surface manner and according to potentially complex patterns, with a small footprint.

However, such an optical sheet imposes a generally flat shape, in which the outgoing rays are perpendicular to the exit surface. The direction of injection is also necessarily close to the general direction of guidance of the optical layer, which limits the shapes of the optical layer and can pose congestion problems.

In addition, the luminous flux emitted towards the outside by the decoupling elements according to the prior art decreases with the distance from the light source, which creates inhomogeneities in the lighting produced by the optical system.

The present invention improves the situation.

To this end, a first aspect of the invention concerns an optical part comprising:

- an input portion capable of receiving light rays coming from at least one light source;

- an output portion capable of directing the light rays towards the outside of the optical part, the output portion comprising at least one intermediate output zone and a final output zone.

The intermediate output zone comprises at least a first intermediate sub-zone capable of directing part of the light rays coming from the light source towards the outside of the optical part, and a second intermediate sub-zone capable of propagating part of the light rays coming from the light source inside the optical part towards another intermediate exit zone or towards the last exit zone.

Thus, the intermediate output element is able to decouple the light flux coming from the source into a part transmitted towards the outside of the optical part, and a part propagated in the optical part, towards another intermediate exit zone or towards the last exit zone. It is thus made possible to create several illuminated zones in the optical part, while ensuring good propagation of the light rays from the light source towards each of the exit zones.

What is more, the propagation through each second intermediate sub-zone of the intermediate output zones makes possible shapes of optical parts more complex than that of the prior art. In fact, the propagation of light rays through the second intermediate sub-zone involves deflecting the light rays in the optical part.

According to one embodiment, for each intermediate output zone, the first intermediate sub-zone may comprise a plurality of elements for transmitting part of the light rays from the light source to the outside of the optical part, and the second intermediate sub-zone may comprise a plurality of elements for propagating part of the light rays from the light source inside the optical part towards another intermediate exit zone or towards the last exit zone.

This embodiment makes it easier to produce complex forms of lighting or signaling.

In addition, each transmission element may be able to direct part of the light rays from the light source towards the outside of the optical part by refraction through the transmission element, and each propagation element may be able to propagate a part of the light rays from the light source towards another intermediate exit zone or towards the last exit zone by reflection towards the interior of the optical part.

Thus decoupling is enabled from simple optical elements integrated into the part and not requiring the addition of additional parts, which reduces the costs of the optical part, ensures a small footprint and makes it possible to produce elements transmission and propagation of small sizes.

In addition or as a variant, for each intermediate output zone, at least some of the propagation elements and the transmission elements can be spatially alternated.

It is thus made possible, particularly when the elements are of small sizes, for example less than 1mm on a side, to give the impression to an external observer that the entire intermediate exit zone transmits light rays. Such an effect is due to the separative power of the eye and is all the more perceptible as an observer moves away from the optical room. The effect is notably obtained when the observer is located at a usual observation distance, in particular of the order of a few meters.

In addition or as a variant, the optical part may comprise at least a first intermediate output zone and a second intermediate output zone, in which:

- a first distribution of the propagation elements and the transmission elements in the first intermediate zone is different from a second distribution of the propagation elements and the transmission elements in the second intermediate zone; and or

- a first ratio between a surface of the first intermediate subzone of the first intermediate zone and a surface of the second intermediate subzone of the first intermediate zone is different from a second ratio between a surface of the first subzone intermediate of the second intermediate zone and a surface of the second intermediate sub-zone of the second intermediate zone.

It is thus made possible to distribute the luminous flux emitted by the light source between the different output zones. It is thus possible to achieve stylish effects, such as a gradation of light intensity, or on the contrary to homogenize the flows transmitted by the output zones.

In addition, the first gear may be lower than the second gear.

Such an embodiment makes it possible to avoid emitting a large part of the luminous flux in the first intermediate output zone, which limits the luminous fluxes emitted by the other output zones, and can give the impression of lighting dysfunctional.

Still additionally, a ratio between the first ratio and the second ratio can be chosen so as to homogenize the luminous fluxes leaving the intermediate output zones and the last output zone respectively.

Thus, the light fluxes respectively transmitted by the different output zones are homogeneous.

According to one embodiment, the last exit zone can only comprise transmission elements capable of directing part of the light rays coming from the light source towards the outside of the optical part.

Thus, the entire luminous flux emitted by the light source is transmitted to the outside of the optical part. The performance of the optical part is thus maximized.

According to one embodiment, the inlet portion and the outlet portion can form an obtuse angle of between 130 and 145°, in particular between 135 and 140°.

Such an embodiment makes it easier to decouple the light rays and also allows the output zones to occupy distinct positions along an axis perpendicular to the main direction of propagation of the light rays in the input portion. Such an embodiment can also facilitate the mounting of the optical part in a lighting or signaling device.

According to one embodiment, the optical part may further comprise a collimator capable of collimating the light rays directly coming from the light source in substantially parallel directions.

It is thus made possible to have light rays parallel to each other in the entrance portion.

According to one embodiment, the optical part may further comprise a reflective surface configured to direct the light rays coming from the collimator towards the input portion of the optical element, and in particular in the main direction of propagation of the light rays in the entry portion.

A second aspect of the invention may comprise an assembly comprising a light source and an optical element according to the first aspect of the invention.

According to one embodiment, the light source is arranged directly facing the input portion of the optical element, or is arranged facing a reflective surface capable of directing the light rays coming from the source towards the portion input of the optical element.

A third aspect of the invention relates to a lighting and/or signaling device comprising an assembly according to the second aspect of the invention.

According to one embodiment, the device comprises a housing closed by a closing glass, defining a volume in which the assembly is placed.

Other characteristics and advantages of the invention will appear on examination of the detailed description below, and the appended drawings in which:

illustrates an optical part according to a first embodiment of the invention, in a longitudinal section;

illustrates a longitudinal sectional view of an assembly of a light source and an optical part according to a second embodiment of the invention;

illustrates a three-dimensional view of the assembly of the , with several light sources;

illustrates propagation elements and transmission elements of an intermediate exit zone of an optical part according to the second embodiment of the invention.

The description focuses on the characteristics that distinguish the optical part from those known in the state of the art.

There illustrates an optical part 100 according to a first embodiment of the invention, in a longitudinal section.

The optical part 100 comprises an input portion 120 capable of receiving light rays 110 coming from at least one light source not shown on the .

The optical part 100 further comprises an outlet portion 130 capable of directing the light rays towards the outside of the optical part 100, the outlet portion comprising a first intermediate outlet zone 131.1, a second intermediate outlet zone 131.2 and a last exit zone 132. The adjective “last” indicates that the last exit zone 132 is the last to be crossed by the light rays 110 coming from the light source, in the general direction of the path of said rays in the optical part. It can in particular be positioned at one end of the optical part, opposite the input portion.

The optical part 100 of the is a guide sheet, that is to say it fulfills a light guide function and for this purpose comprises two guide faces 138 and 139 and a lateral periphery not shown on the .

A guide sheet is a light guide whose thickness is small compared to its length and width. It can possibly be curved and have a given curve. However, in the preferred embodiments described, the optical part is not curved. Thus the sheet has a first guide face 138 and a second guide face 139 extended, separated by a lateral periphery, this periphery defining a thickness of the sheet, which can be variable, for example decreasing from one end to the other . These first and second extended faces form guide faces delimiting a zone of propagation of light rays, by total internal reflection on these faces. The perimeter defines a thickness of the guide sheet which can be of the order of a few millimeters.

The first face 138 further comprises the output portion 130 and thus fulfills a lighting function in addition to guiding the light into the optical part 100. The first face 138 can thus be called "front face", while the second face 139 can be called “rear side”.

No restriction is attached to the number of intermediate output zones, the optical part 100 comprising at least one intermediate output zone. An example with two intermediate output zones 131.1 and 131.2 is given for illustration purposes only.

The first intermediate output zone 131.1 comprises a first intermediate sub-zone 133.1 capable of directing part of the light rays 110 towards the outside of the optical part 100, and a second intermediate sub-zone 134.1 capable of propagating part of the rays light 110, towards the second intermediate exit zone 131.2.

The second intermediate exit zone 131.2 also comprises a first intermediate sub-zone 133.2 capable of directing a portion of the light rays 110 propagated by the second intermediate sub-zone 134.1 of the first intermediate exit zone 131.1, towards the outside of the room optical 100, and a second intermediate sub-zone 134.2 capable of propagating part of the light rays 110 propagated by the second intermediate sub-zone 134.1 of the first intermediate output zone 131.1, towards the last output zone 132.

The last output zone 132 comprises only a zone 133.3, comparable to the first intermediate sub-zones 133.1 and 133.2, capable of directing part of the light rays 110 propagated by the second intermediate sub-zone 134.2 of the second intermediate output zone 131.2, towards the outside of the optical part 100.

Thus, each intermediate output zone transmits to the outside of the optical part 100 part of the luminous flux coming from the source and propagates another part towards the following intermediate output zone, or towards the last output zone. It is thus made possible to create several illuminated zones in the optical part, while ensuring good propagation of the light rays from the light source towards each of the exit zones.

The fact that part of the light rays is transmitted "towards" the next intermediate exit zone or towards the last exit zone, indicates that the light rays are directed into the optical part so as to reach directly, or after one or more reflections on the internal faces of the optical part, the next intermediate exit zone or the last exit zone.

What is more, the propagation through each second intermediate sub-zone of the intermediate output zones makes possible shapes of optical parts more complex than those of the prior art, although a simple shape is illustrated on the .

It is also made possible to control, by decoupling, the distribution between luminous flux propagated inside the optical part and luminous flux transmitted to the outside by each intermediate output zone, as a function of the first and second sub-zones intermediaries.

The first intermediate sub-zones 133.1, 133.2 and zone 133.3 can transmit light rays by refraction. No restriction is attached to the material of the first intermediate sub-zones 133.1, 133.2 and zone 133.3, nor to their shape. The optical part 100 may in particular be made of PMMA (polymethyl methacrylate), PC (polycarbonate), glass, or more generally any transparent material with a refractive index higher than that of the medium in which the optical part is installed, air in particular. The first intermediate sub-zones 133.1, 133.2 and zone 133.3 may comprise a set of refraction elements, not shown on the . No restriction is attached to the shape of the refractive elements which can be curved, for example in the shape of a portion of a torus.

The second intermediate sub-zones 134.1 and 134.2 can propagate the light rays in the optical part 100 by reflection. The second intermediate sub-zones may in particular comprise a set of reflection elements, such as a set of mirrors, not shown on the . According to an advantageous embodiment, the reflection elements are configured to reflect the light rays coming from the light source(s) which impact them by total internal reflection.

According to one embodiment, a first distribution of the propagation elements and the transmission elements in the first intermediate zone 131.1 is different from a second distribution of the propagation elements and the transmission elements in the second intermediate zone 131.2. In addition or as a variant, a first ratio between the surface of the first intermediate subzone 133.1 of the first intermediate zone 131.1 and the surface of the second intermediate subzone 134.1 of the first intermediate zone 131.1 is different from a second ratio between the surface of the first intermediate subzone 133.2 of the second intermediate zone and the surface of the second intermediate subzone 134.2 the second intermediate zone.

Thus, it is possible to distribute the luminous flux between the three output zones, to create patterns, a gradation of intensity, or to homogenize the luminous flux transmitted to the outside by the output zones.

There illustrates an assembly of a light source and an optical part 200 in longitudinal section according to a second embodiment of the invention.

The optical part 200 comprises an input portion 220 capable of receiving light rays 210 coming from at least one light source 215. It should be noted that on the , the light source is symbolized by a point representing its position. Optionally, the optical part 200 may comprise a collimator 205 capable of collimating the light rays emitted directly by the source in substantially parallel directions. In particular, in the example of the , the rays coming from the light source 215 are collimated in a substantially vertical direction and directed downwards on the , so as to then be reflected by a reflection surface 225 in the main direction of propagation of the input portion, corresponding to the direction , in light rays 210.

The optical part 200 further comprises an outlet portion 230 capable of directing the light rays towards the outside of the optical part 200, the outlet portion 230 comprising a first intermediate outlet zone 231.1, a second intermediate outlet zone 231.2, a third intermediate output zone 231.3 and a last output zone 232. As for the first embodiment, the adjective “last” indicates that the last output zone 232 is the last to be crossed by the light rays 210 coming from the light source 215, in the general direction of the path of said rays in the optical part. It can in particular be positioned at one end of the optical part, opposite the input portion.

The optical part 200 of the is a guide sheet with an inlet portion 220 and an outlet portion 230 forming a non-zero angle. The optical part 200 fulfills a light guide function. For this purpose, the outlet portion comprises a first guide face 238, a second guide face 239 and a lateral periphery not shown on the . The inlet portion 220 also includes two guide faces and a lateral periphery, but these elements are not referenced on the .

The first and second extended guide faces 238 and 239 are thus separated by a lateral periphery, this periphery defining a thickness of the outlet portion 230 of the sheet, which can be variable, for example decreasing from one end to the other . These extended faces form guide faces delimiting a zone of propagation of light rays, by total internal reflection on these faces. The perimeter defines a thickness of the guide sheet which can be of the order of a few millimeters

The first face 238 further comprises the output portion 230 and thus fulfills a lighting function in addition to guiding the light into the optical part 200. The first face 238 can thus be called "front face", while the second face 239 can be called “rear side”.

No restriction is attached to the number of intermediate output zones, the optical part 200 comprising at least one intermediate output zone. An example with three intermediate output zones 231.1, 231.2 and 231.3 is given for illustration purposes only.

The first intermediate exit zone 231.1 includes:

- a first intermediate sub-zone capable of directing part of the light rays 210 towards the outside of the optical part 200, into a set 235.1 of light rays, and

- a second intermediate sub-zone capable of propagating part of the light rays 210 towards the second intermediate output zone 231.2, in a set 236.1 of light rays. Intermediate subzones 233.1 and 233.2 will be better understood with reference to Figures 2b and 3.

The second intermediate exit zone 231.2 includes:

- a first intermediate sub-zone capable of directing part of the light rays 210, in particular the assembly 236.1 propagated by the first intermediate output zone 231.1 and reflected by the rear face 239, towards the outside of the optical part 200 in one set 235.2 of light rays, and

- a second intermediate sub-zone capable of propagating part of the light rays 210, in particular the assembly 236.1 propagated by the first intermediate output zone 231.1 and reflected by the rear face 239, towards the third intermediate output zone 231.3 as a whole 236.2 of light rays.

The third intermediate exit zone 231.3 includes:

- a first intermediate sub-zone capable of directing part of the light rays 210, in particular the assembly 236.2 propagated by the second intermediate output zone 231.2 and reflected by the rear face 239, towards the outside of the optical part 200 in one set 235.3 of light rays, and

- a second intermediate sub-zone capable of propagating a part of the light rays 210, in particular the assembly 236.2 propagated by the second intermediate output zone 231.2 and reflected by the rear face 239, towards the last output zone 232 in an assembly 236.3 of light rays.

The last output zone 232 comprises only an output zone, comparable to the first intermediate sub-zones of the intermediate output zones, capable of directing part of the light rays 110, in particular the assembly 236.3 propagated by the third intermediate output zone 231.2 and reflected by the rear face 239, towards the outside of the optical part 200.

Thus, each intermediate output zone transmits to the outside of the optical part 200 part of the luminous flux coming from the source and propagates another part towards the following intermediate output zone, or towards the last output zone. It is thus made possible to create several illuminated zones in the optical part, while ensuring good propagation of the light rays from the light source towards each of the exit zones.

What is more, the propagation through each second intermediate sub-zone of the intermediate output zones makes possible shapes of optical parts more complex than those of the prior art. In particular, as illustrated in the , the invention makes it possible to provide a non-zero angle 290 between the input portion which receives the light rays 210 coming from the light source 205, and the output portion 230 which performs the lighting or signaling function. The angle 290 is preferably an obtuse angle between 130 and 145°, in particular between 135 and 140°, so as to facilitate the decoupling between the light rays transmitted towards the outside of the optical part 100 and the light rays propagated in the optical part, for each intermediate output zone.

The angle 290 makes it possible to distribute the positions of the intermediate exit zones and the last exit zone along an axis Z perpendicular to the main axis front face 238 of the output portion 230 can be made visible by an observer located outside a lighting and/or signaling device integrating the optical part 200, which gives a “floating” appearance to the function light achieved.

The Z axis shown on the is vertical. However, the intermediate exit zones and the last exit zone can alternatively be distributed along a Y axis normal to the plane of the .

There presents a three-dimensional view of the assembly with the optical part 200 of the .

In the example shown, the assembly comprises three light sources 215.1, 215.2 and 215.3, and three collimators 205.1, 205.2 and 205.3, each associated respectively with one of the light sources, and capable of collimating the light rays respectively emitted by the three sources in the input portion 220. Such collimators are well known to those skilled in the art. They can have several possible forms, and can for example:

- operate only by refraction of light rays coming from the source; Or

- present a central zone operating by refraction and a peripheral zone operating by refraction then reflection of the light rays coming from the light source.

As previously described, the first intermediate output zone 231.1 comprises a first intermediate sub-zone 233.1 comprising a set of elements for transmitting part of the light rays 210 towards the outside of the optical part 200, and a second sub-zone intermediate zone 234.1 comprising a set of elements for propagating part of the light rays 210 towards the second intermediate output zone 231.2.

The second intermediate output zone 231.2 comprises a first intermediate sub-zone 233.2 comprising a set of elements for transmitting part of the light rays 210 towards the outside of the optical part 200, and a second intermediate sub-zone 234.1 comprising a set of elements for propagating part of the light rays 210 towards the third intermediate output zone 231.3.

The third intermediate output zone 231.3 comprises a first intermediate sub-zone 233.3 comprising a set of elements for transmitting part of the light rays 210 towards the outside of the optical part 200, and a second intermediate sub-zone 234.3 comprising a set of elements for propagating part of the light rays 210 towards the last exit zone 232.

The second output zone 232 comprises only a zone 233.4 comprising elements for transmitting part of the light rays 210 coming from the light sources, then successively propagated by the second intermediate sub-zones 234.1, 234.2 and 234.3, and reflected by the face rear 239, towards the outside of the optical part 200.

As for the first embodiment, the transmission elements of the first intermediate sub-zones 233.1, 233.2 and 233.3, and of the exit zone 233.4, can transmit the light rays towards the outside by refraction, while the propagation elements second intermediate sub-zones 234.1, 234.2 and 234.3 can propagate the light rays in the output portion 230 by reflection.

There is a view of an intermediate output zone showing the different transmission elements 301 and propagation 302 of first and second intermediate sub-zones.

The transmission elements 301 by refraction are able to refract part of the light rays 210, possibly propagated beforehand by the second intermediate sub-zones 234.1 to 234.3 and reflected by the rear face 239, towards the outside of the optical part 200, into a light beam 235.

The propagation elements 302 by reflection are able to reflect part of the light rays 210, possibly propagated beforehand by the second intermediate sub-zones 234.1 to 234.3 and reflected by the rear face 239, towards the interior of the optical part 200, into a light beam 236.

As for the first embodiment, and as shown in the , the transmission elements 301 and the propagation elements 302 can be alternated spatially, for example to form a checkerboard, which allows, particularly when the elements are of less than 1 mm side size, to illuminate over the entire intermediate output zone while propagating part of the luminous flux coming from the sources towards the next intermediate output zone, or towards the last output zone, at an identical position along the Y axis.

The intermediate exit zones can thus occupy the same positions in Y and have the same width in this direction.

Furthermore, as shown in the , the last exit zone 232 can be wider than the intermediate exit zones 231.1, 231.2 and 231.3, in particular so as to receive the entire luminous flux emitted by the source 215.3, when the assembly includes several light sources.

As for the first embodiment, it is made possible to control the distribution between propagated luminous fluxes and luminous fluxes transmitted to the outside by each intermediate output zone, as a function of the first and second intermediate sub-zones.

The first intermediate sub-zones 233.1, 233.2, 233.3 and zone 233.4 can transmit light rays to the outside by refraction. No restrictions are attached to the material of the first intermediate subzones 233.1, 233.2, 233.3 and zone 233.4, nor to their shape. The optical part 200 may in particular be made of plastic material, such as PMMA (polymethyl methacrylate), PC (polycarbonate), or glass, or more generally of any transparent material with a higher refractive index than that of the medium in which is installed the optical part, the air in particular.

As for the first embodiment, a first distribution of the propagation elements 302 and the transmission elements 301 in one of the intermediate zones may be different from a second distribution of the propagation elements and the transmission elements in another zone. output intermediary. In addition or as a variant, a first ratio between the surface of the first intermediate sub-zone of an intermediate output zone and the surface of the second intermediate sub-zone of the intermediate output zone may be different from a second ratio between the surface of the first sub-zone of another intermediate output zone and the surface of the second sub-zone of said other intermediate output zone.

Thus, it is possible to distribute the luminous flux between the intermediate output zones and the last output zone, to produce patterns, a gradation of intensity, or to homogenize the luminous fluxes transmitted to the outside by the different zones of exit. According to an advantageous mode, the aforementioned ratios decrease when passing from one intermediate zone to the next, in the direction of propagation of the light rays.

As appears in the figures, the exit zones of the parts 100 and 200 are separated from each other, which implies that at least part of the exit portion located between two exit zones does not transmit any light ray towards the exterior of the optical part 100 or 200.

The optical parts 100 and 200 described above can be assembled with one or more light sources, then the assembly can be integrated into a lighting and/or signaling device, in particular for a motor vehicle. No restriction is associated with the light source or sources assembled with the optical parts 100 and 200. For example, the light sources can be of the LED type.

The present invention is not limited to the embodiments described above by way of examples; it extends to other variants.

Claims (11)

Optical part (100; 200) comprising:

• an input portion (120; 220) capable of receiving light rays (110; 210) coming from at least one light source (215; 215.1; 215.2; 215.3);
• an output portion (130; 230) capable of directing the light rays towards the outside of the optical part, the output portion comprising at least one intermediate output zone (131.1; 131.2; 231.1; 231.2; 231.3) and a final exit zone (132; 232),

in which the intermediate output zone comprises at least a first intermediate sub-zone (133.1; 133.2; 233.1; 233.2; 233.3) capable of directing part of the light rays coming from the light source towards the outside of the optical part, and a second intermediate sub-zone (134.1; 134.2; 234.1; 234.2; 234.3) capable of propagating part of the light rays coming from the light source inside the optical part towards another intermediate exit zone or towards the last exit area. Optical part according to claim 1, in which, for each intermediate output zone (131.1; 131.2; 231.1; 231.2; 231.3), the first intermediate sub-zone (133.1; 133.2; 233.1; 233.2; 233.3) comprises a plurality of transmission elements (301) of part of the light rays of the light source (215; 215.1; 215.2; 215.3) towards the outside of the optical part (100; 200), and the second intermediate sub-zone (134.1 ;134.2; 234.1; 234.2; 234.3) comprises a plurality of propagation elements (302) of a part of the light rays of the light source inside the optical part towards another intermediate exit zone or towards the last exit zone (132; 232). Optical part according to claim 2, in which each transmission element (301) is capable of directing part of the light rays (110; 210) coming from the light source (215; 215.1; 215.2; 215.3) towards the outside of the optical part (100; 200) by refraction through the transmission element, and in which each propagation element (302) is able to propagate part of the light rays from the light source towards another intermediate output zone (131.1 131.2; 231.1; 231.2; 231.3) or towards the last exit zone (132; 232) by reflection towards the interior of the optical part. Optical part according to claim 2 or 3, in which, for each intermediate output zone (131.1; 131.2; 231.1; 231.2; 231.3), at least some of the propagation elements (302) and transmission elements (301) are alternated spatially. Optical part according to one of claims 2 to 4, comprising at least a first intermediate output zone (131.1; 231.1) and a second intermediate output zone (131.2; 231.2; 231.3), in which:

• a first distribution of the propagation elements (302) and the transmission elements (301) in the first intermediate output zone is different from a second distribution of the propagation elements and the transmission elements in the second intermediate output zone; and or
• a first ratio between an area of the first intermediate sub-zone (133.1; 233.1) of the first intermediate zone and an area of the second intermediate sub-zone (134.1; 234.1) of the first intermediate zone is different from a second ratio between a surface of the first intermediate sub-zone (133.2; 233.2; 233.3) of the second intermediate zone and a surface of the second intermediate sub-zone (134.2; 234.2; 234.3) of the second intermediate zone.

Optical part according to claim 5, in which the first ratio is lower than the second ratio. Optical part according to one of the preceding claims, in which the last exit zone (132; 232) only comprises transmission elements (301) capable of directing part of the light rays coming from the light source (215; 215.1; 215.2; 215.3) towards the outside of the optical part (100; 200). Optical part according to one of the preceding claims, in which the input portion (220) and the output portion (230) form an obtuse angle of between 130 and 145°, in particular between 135 and 140°. Optical part according to one of the preceding claims, further comprising a collimator (205) capable of collimating the light rays directly coming from the light source (215; 215.1; 215.2; 215.3) in substantially parallel directions. Assembly comprising a light source (215; 215.1; 215.2; 215.3) and an optical element (100; 200) according to one of the preceding claims. Lighting and/or signaling device comprising an assembly according to claim 10.