EP4325115A1

EP4325115A1 - Automotive light comprising a light guide

Info

Publication number: EP4325115A1
Application number: EP22190581.3A
Authority: EP
Inventors: Cristina PORCELLI; Matteo DE ROSA
Original assignee: Marelli Automotive Lighting Italy SpA
Current assignee: Marelli Automotive Lighting Italy SpA
Priority date: 2022-08-16
Filing date: 2022-08-16
Publication date: 2024-02-21

Abstract

Automotive light (1) comprising: a rear body (2) adapted to be fixed on the vehicle; a front half-shell (3) arranged to close the mouth of said rear body (2); and at least one lighting assembly (4) which is located inside the rear body (2) and is adapted to backlight a corresponding transparent or semi-transparent sector of the front half-shell (3); said lighting assembly (4) comprising: a collimated or quasi-collimated light source (5) that produces and directs towards the front half-shell (3) at least one light beam (f) collimated or quasi-collimated in a predetermined first direction (d1); and a corrective optics (10) with plate-like structure, which is interposed between the collimated or quasi-collimated light source (5) and the front half-shell (3), and is adapted to deflect said light beam (f) in a second direction (d₂) inclined with respect to said first direction (d₁), and which is moreover structured so as to reflect, towards the rear body (2) and/or towards the collimated or quasi-collimated light source (5), at least a part of the light rays that reach the inner face (10i) of the corrective optics (10) and do not belong to said light beam (f).

Description

TECHNICAL FIELD

The present invention relates to an automotive light.
In more detail, the present invention relates to a headlight or taillight for cars and similar vehicles, i.e. a lighting apparatus adapted to be incorporated into a motor vehicle with the function of signalling the position, the sudden deceleration and/or the turning direction of the vehicle, and/or with the function of lighting the area surrounding the vehicle. Use to which the disclosure that follows will make explicit reference without thereby losing generality.

BACKGROUND ART

As is well known, a headlight or taillight for cars and similar motor vehicles is, conventionally, a lighting device which is placed at the front, rear or side part of the vehicle and has the function of lighting the area around the vehicle and/or the function of signalling the position of the vehicle, the sudden deceleration of the vehicle and/or the turning direction of the vehicle, in accordance with certain photometric approval standards.
Most of the taillights for cars and similar motor vehicle usually comprises: a rigid and substantially basin-shaped rear body, which is structured so as to be stably recessed into a compartment specially realized in the rear part of the bodywork of the vehicle; a front half-shell which is arranged to close the mouth of the body so as to surface outside of the bodywork of the vehicle, and is generally provided with a plurality of transparent or semi-transparent sectors, optionally differently coloured from one another; and a series of lighting assemblies that are located inside the rear body, each immediately beneath a respective transparent or semi-transparent sector of the front half-shell, so as to be able to selectively backlight the overlying transparent or semi-transparent sector of the front half-shell.
Usually, each transparent or semi-transparent sector of the front half-shell is moreover uniquely connected to a specific light signal, thus each lighting assembly is specifically structured so as to emit, on command, a light beam that, once come out from the automotive light through the corresponding transparent or semi-transparent sector of the half-shell, meets the photometric approval specifications (colour and light distribution) provided for the corresponding light signal.
Over the past few years, many car manufacturers have chosen to equip their new car models with taillights which, using a series of LEDs (acronym for Light Emitting Diode) as light sources, are able to create elaborate plays of light that, at night, allow the car model to be uniquely identified.
Evidently, the use of LEDs has radically changed the structure of the lighting assemblies, because the LEDs are point-type light sources that emit, in Lambertian manner, a light beam with a rather narrow opening angle.
In the new taillights, in fact, the lighting assemblies can use reflector bodies, corrective optics and shielding masks to adapt the light beam emitted by the various LEDs to the photometric and aesthetic needs connected with the automotive use.
In other words, the reflector bodies, the corrective optics and the shielding masks are interposed between the LEDs and the front half-shell, and are overall structured so that the light beams reaching the inner face of the front half-shell, are able to backlight the corresponding sectors of the front half-shell in a substantially uniform manner, and have, once crossed the front half-shell, a main component of the light beam substantially parallel to a predetermined direction and/or to the optical axis of the taillight, so as to meet the photometric approval specifications.
In more detail, some models of taillights for cars are provided with lighting assemblies that comprise: a reflector body which is placed close to the bottom of the rear body and is provided with a series of concave reflective surfaces with a roughly semi-parabolic profile, each of which is oriented so as to reflect the incident light towards the facing transparent or semi-transparent sector of the front half-shell; and a series of LEDs that are placed on the side of the reflector body and are oriented so as to direct the produced light towards the various reflective surface of the reflector body.
In addition, since in some cases the shape of the front half-shell is rather oblong and curved, the lighting assemblies may also be provided with a transparent body with a plate-like structure, which is interposed between the reflector body and the front half-shell so as to be crossed by the light directed towards the front half-shell, and is provided with a corrective optic shaped so as to deflect and redistribute the light coming from the reflector body.
In more detail, the corrective optic consists of an embossed profile with a complex three-dimensional structure, which is made on the inner or outer face of the plate-like body and is composed of a multitude of refractive prisms suitably shaped so as deflect the incident light in a predetermined manner towards the front half-shell.
Unfortunately, despite the presence of the corrective optic, experimental tests have highlighted that the intensity of the light beam on exit from the taillight often has a spatial distribution that differs slightly from the one expected in the design phase. Difference very evident when the shape of the front half-shell is particularly oblong and/or curved.
In fact, in addition to the expected high brightness area placed at the optical axis of the taillight, very often the isocandela diagram of the taillight also highlights the presence of small additional areas/zones with medium brightness, clearly not expected and not desired, which are usually placed in the peripheral zone of the isocandela diagram.
This implies that the light beam, on exit from the taillight, has secondary/spurious components having a preferential direction that is strongly inclined with respect to the optical axis of the taillight.
In other words, while observing the front half-shell of the taillight, as one moves from the optical axis of the taillight towards the vehicle outer side, the intensity of the light exiting from the taillight will gradually decrease, and then suddenly increase due to the secondary/spurious components of the light beam.
Clearly, despite having a relatively low intensity, if one observes the taillight from a position that is greatly angled with respect to the optical axis, the secondary/ spurious components of the light beam exiting from the automotive light may alter the perception of the plays of light produced by the taillight, with the lower aesthetic impact that follows.

SUMMARY OF THE INVENTION

Aim of the present invention is to improve the distribution of the light within the taillight, so as to avoid, or at least reduce, the effects of the secondary/ spurious components of the light beam exiting from the taillight.
In accordance with these aims, according to the present invention there is provided an automotive light as defined in Claim 1 and preferably, though not necessarily, in any one of the claims depending on it.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be described with reference to the attached drawings, which show a non-limiting embodiment thereof, wherein:

Figure 1 is a perspective view of an automotive light realized according to the teachings of the present invention, with parts in section and parts removed for clarity's sake;
Figure 2 is a partially exploded perspective view of the automotive light shown in Figure 1, with parts removed for clarity's sake;
Figure 3 is a perspective view of a lighting assembly of the automotive light shown in Figure 1, with parts removed for clarity's sake;

Figures 4 and 5 are two perspective views of the lighting assembly shown in Figure 3, with parts in section and parts removed for clarity's sake; whereas
Figures 6 and 7 schematically show the operation of the lighting assembly shown in Figures 3, 4 and 5.

DETAILED DESCRIPTION OF THE EMBODIMENTS

With reference to Figures 1, 2 and 3, number 1 denotes as a whole an automotive light, i.e. a lighting apparatus particularly adapted to be firmly fixed on the front or rear part of the bodywork of a motor vehicle, with the function of emitting light signals adapted to signal/indicate the position of the vehicle and/or the sudden deceleration of the vehicle and/or the turning direction of the vehicle during travel and/or with the function of lighting the area surrounding the vehicle.
In other words, the automotive light 1 is adapted to be fixed on the front or rear part of the bodywork of a car, van, truck, motorcycle or other similar motor vehicle, to perform the function of headlight or taillight.
Clearly the automotive light 1 may also be placed on a side flank of the car or other similar motor vehicle.
Preferably, the automotive light 1 is furthermore structured to be stably recessed in the vehicle bodywork (not shown) so as to surface outside of the latter.
In the example shown, in particular, the automotive light 1 is preferably structured so as to be stably recessed in the rear part of the bodywork of a car or other similar motor vehicle.
In other words, the automotive light 1 is preferably a taillight for cars and the like.
Obviously, in a different embodiment the automotive light 1 may also be structured so as to be simply fixed cantilevered on the front, side or rear part of the vehicle bodywork (not shown).
With reference to Figures 1, 2 and 3, the automotive light 1 in particular comprises: a substantially rigid and preferably made of plastic material, rear body 2 which is substantially basin-shaped, and is structured so as to be firmly fixed to the vehicle bodywork (not shown); and an at least partially transparent and preferably made of plastic material, substantially rigid front half-shell 3 which is arranged to close the mouth of the rear body 2, preferably so as to surface outside of the vehicle bodywork.
In more detail, the front half-shell 3 is preferably fixed to the perimeter edge of the mouth of rear body 2 in a substantially fluid-tight manner.
In addition, the automotive light 1 moreover comprises one or more electrically-powered lighting assemblies, each of which emits light on command and is placed inside the rear body 2, beneath a corresponding transparent or semi-transparent sector of front half-shell 3, so as to be able to selectively backlight the same transparent or semi-transparent sector of the front half-shell 3, preferably separately and independently from the other lighting assemblies of the automotive light.
Optionally, one or more transparent or semi-transparent sectors of the front half-shell 3 may also be coloured. Clearly, the front half-shell 3 may also include opaque sectors.
Furthermore, at least one of the lighting assemblies of automotive light 1 is preferably structured so as to direct the light produced towards the corresponding and facing transparent or semi-transparent sector of front half-shell 3, with a main component of the light beam substantially parallel to a reference optical axis A, which is preferably locally substantially parallel to the longitudinal axis of the vehicle when the automotive light 1 is correctly mounted/ placed on the bodywork of the vehicle.
In more detail, the rear body 2 is preferably made of an opaque plastic material advantageously via injection moulding, and is preferably structured so as be at least partially recessed into a seat specially made in the rear part of the vehicle bodywork.
Obviously, in a different embodiment, the rear body 2 may also be structured so as to be at least partially recessed into a seat specially made in the front or side part of the vehicle bodywork (not shown), or so as to be simply fixed cantilevered on the front, side or rear part of the vehicle bodywork.
The front half-shell 3 is preferably made of a transparent plastic material, such as polymethylmethacrylate (PMMA) or polycarbonate (PC), advantageously via injection moulding.
Preferably the front half-shell 3 is furthermore welded to the rear body 2 along the perimeter edge of the mouth of the latter.
With reference to Figures 1 to 5, the or at least one of the lighting assemblies of automotive light 1, hereinafter denoted by number 4, in turn comprises a collimated or quasi-collimated light source 5, which is structured so as produce and direct, towards the front half-shell 3, at least one light beam f which is collimated or quasi-collimated in a predetermined first direction d₁ and optionally also has a predetermined opening angle α preferably, though not necessarily, lower than 15°.
In other words, the light beam f produced by the collimated or quasi-collimated light source 5 is made up (entirely) of light rays r parallel to the direction d₁ and/or of light rays r inclined with respect to the direction d₁ by a maximum angle equal to half the opening angle α of the light beam. Clearly, the collimated or quasi-collimated light source 5 emits/can emit also light rays external to said light beam f, hereinafter called spurious light rays r₀.
In more detail, the collimated or quasi-collimated light source 5 preferably comprises: a substantially rigid and preferably made of plastic material, reflector body 6 which is placed inside the rear body 2, preferably adjacent the bottom thereof, and is provided with at least one concave reflective surface 6a preferably with a substantially semi-parabolic profile, which is oriented so as reflect the incident light towards the facing transparent or semi-transparent sector of the front half-shell 3; and an electrically-powered light emitting device 7, preferably with a plate-like structure, which emits light on command and is arranged inside the rear body 2 by the side of the reflector body 6 and advantageously also adjacent the bottom of rear body 2, so as to direct the light produced towards the concave reflective surface 6a of reflector body 6.
In addition, said at least one concave reflective surface 6a of reflector body 6 is preferably shaped so as to reflect, towards the front half-shell 2, the light coming from the light emitting device 7, while forming a light beam f that is collimated or quasi-collimated in direction d₁.
In the example shown, in particular, the collimated or quasi-collimated light source 5 is preferably structured so as produce and direct, towards the front half-shell 3, a plurality of light beams f separated and distinct from one another, each of which is directed towards a corresponding portion of the front half-shell 3 and is collimated or quasi-collimated in a corresponding predetermined direction d₁.
In more detail, with reference to Figures 2 to 6, the reflector body 6 is preferably provided with a plurality of concave reflective surfaces 6a advantageously arranged side by side to one another, each of which is preferably shaped so as to reflect the incident light towards the front half-shell 2, while forming a respective light beam f collimated or quasi-collimated in a corresponding predetermined direction d₁.
The light emitting device 7, in turn, is preferably structured so as direct the produced light towards the various concave reflective surfaces 6a of reflector body 6.
In the example shown, in particular, the or each light beam f is quasi-collimated in the relative direction d₁ and has an opening angle α advantageously equal to about 6°.
In other words, the light beam f is basically made up of light rays r parallel to direction d₁ and of light rays r inclined with respect to direction d₁ by a maximum angle equal to about ±3°.
Preferably, the light emitting device 7 in turn includes one or more LEDs (acronym for Light Emitting Diode), which are placed by the side of reflector body 6, preferably adjacent the bottom of rear body 2, and are oriented so as to direct the produced light towards the concave reflective surface(s) 6a of reflector body 6.
In more detail, with reference to Figures 2, 3, 4, 5, the light emitting device 7 preferably comprises: at least one printed circuit board 8, which is arranged skimmed over or in abutment onto the reflector body 6, by the side of the concave reflective surface(s) 6a; and a series of LEDs 9 that are arranged on the printed circuit board 8 so as to directly face the concave reflective surface(s) 6a of reflector body 6. Preferably, though not necessarily, the printed circuit board 8 moreover hosts the electronics that is adapted to power and/or drive the LED(s) 9.
Preferably the LEDs 9 are furthermore structured so as emit a light beam (i.e. the light cone in which at least 50% of the light energy produced/emitted by the LED is conventionally concentrated) with an opening angle advantageously lower than or equal to 60°, and are preferably oriented so that each LED 9 directs its own light beam substantially only towards the corresponding and facing concave reflective surface 6a of reflector body 6.
The or each concave reflective surface 6a of reflector body 6, in turn, preferably has a substantially semi-parabolic profile with a complex three-dimensional structure, so as to be able to reflect the light rays coming from the LED or LEDs 9 towards the front half-shell 3, forming the light beam f.
With reference to Figures 1 to 5, in addition the lighting assembly 4 also comprises a plate-like corrective optic, which is interposed between the collimated or quasi-collimated light source 5 and the front half-shell 3, preferably spaced from both, so as to be crossed by the light beam f directed towards the front half-shell 3, and is structured so as deflect the light beam f in a predetermined second direction d₂, suitably inclined with respect to direction d₁.
In more detail, the lighting assembly 4 is additionally provided with a substantially rigid plate-like body 10, at least partially transparent and preferably made of plastic material, which is interposed between the collimated or quasi-collimated light source 5 and the front half-shell 3, preferably spaced from both, so as to be crossed by the light beam f directed towards the front half-shell 3, and is provided with a corrective optics that is adapted to deflect the light beam f in a predetermined second direction d₂, suitably inclined with respect to direction d₁.
In other words, the plate-like body 10 is preferably interposed between the reflector body 6 and the front half-shell 3.
The plate-like body 10 moreover has a higher refractive index than that of the air, and its corrective optic is shaped so as deflect the light beam f in a second direction d₂, which is inclined with respect to the direction d₁ by a predetermined angle β preferably ranging between 0° and 50° and advantageously even greater than 5°.
More specifically, the deflection angle β preferably depends on the transparent material which the lenticular body 10 is made of, or rather it depends on its refractive index.
Preferably the direction d₂ is moreover substantially parallel to the optical axis A of the automotive light.
In the example shown, in particular, the plate-like body 10 is preferably made entirely of transparent polycarbonate (PC) advantageously by injection moulding, but may also be made of polymethylmethacrylate (PMMA) or other similar plastic materials.
In addition, the corrective optics of plate-like body 10 is moreover structured so as to reflect at least a part of the light rays that reach the inner face of plate-like body 10 and do not belong to the collimated or quasi-collimated light beam f in the direction d₁, i.e. at least a part of the spurious light rays ro, again towards the rear body 2 and/or towards the collimated or quasi-collimated light source 5.
In other words, the corrective optics of plate-like body 10 prevent at least a part of the spurious light rays r₀ from reaching the front half-shell 3.
In more detail, with reference to Figures 2, 3, 4 and 5, the plate-like body 10 is provided with a rear or inner face 10i turned towards the collimated or quasi-collimated light source 5, or rather towards the reflector body 6, and a front or outer face 10e turned towards the front half-shell 3.
In addition, the rear/inner face 10i and the front/outer face 10e of plate-like body 10 have respective embossed portions with a complex three-dimensional structure, which contribute in forming the corrective optics of the plate-like body 10.
In more detail, the rear/inner face 10i of plate-like body 10 has, at the corrective optic, at least a first embossed portion with a complex three-dimensional structure, which forms/includes a plurality of first protruding refractive prisms 11, each of which is shaped so as to deflect/direct, depending on the angle of incidence, the incident light towards the front/outer face 10e of plate-like body 10, or towards the collimated or quasi-collimated light source 5 and/or the rear body 2.
The front or outer face 10e of plate-like body 10, on the other hand, has at least a second embossed portion with a complex three-dimensional structure, complementary to the first embossed portion, which is aligned with the first embossed portion and forms/includes a plurality of second protruding refractive prisms 12, each of which is shaped so as deflect the light rays coming from the rear/inner face 10i, or rather from the refractive prisms 11, alternately towards the front half-shell 3 or again towards the rear/inner face 10i of plate-like body 10, and therefore towards the collimated or quasi-collimated light source 5 and/or the rear body 2, depending on the direction of the incident light ray.
In more detail, with reference to Figures 6 and 7, the refractive prisms 11 present on the rear/inner face 10i of plate-like body 10 are provided with a main light-entry surface 11a preferably slightly convex, and with at least one, preferably substantially flat, secondary light-entry surface 11b that is contiguous and inclined with respect to the main refractive surface 11a.
Each main light-entry surface 11a, therefore, is preferably interposed between two secondary light-entry surfaces 11b.
The refractive prisms 12 present on the front/outer face 10e of plate-like body 10, on the other hand, are provided with a light-exit surface 12a preferably slightly convex, and with at least one, preferably substantially flat, reflective surface 12b that is contiguous and inclined with respect to the light-exit surface 12a.
Each light-exit surface 12a, therefore, is preferably interposed between two reflective surfaces 12b.
With particular reference to Figures 6 and 7, the main light-entry surface 11a of refractive prisms 11 faces the collimated or quasi-collimated light source 5, so as to be struck by the light rays r belonging to the light beam f with an angle of incidence smaller than the limit angle.
In this way, the light rays r of the light beam f can freely penetrate within the corrective optics of plate-like body 10.
In more detail, the main light-entry surface 11a of the refractive prisms 11 is preferably substantially perpendicular to the direction d₁.
In addition, the main light-entry surface 11a of the refractive prisms 11 is shaped so as deflect, or rather refract, the light rays r of light beam f towards the light-exit surface 12a of at least one corresponding refractive prism 12 present on the front/outer face 10e of plate-like body 10, with an angle of incidence lower than the limit angle, so that the light rays r can freely exit the plate-like body 10.
Preferably, the light-exit surfaces 12a of the refractive prisms 12 are moreover shaped so that the light rays r exiting from the front/outer face 10e of plate-like body 10 are additionally collimated or quasi-collimated in a direction substantially parallel to the direction d₂.
In addition, the main light-entry surface 11a of the refractive prisms 11 is preferably also shaped so as to deflect at least a part of the incident spurious light rays r₀ towards the reflective surface 12b of at least one corresponding refractive prism 12 present on the front/outer face 10e of plate-like body 10, with an angle of incidence greater than or equal to the limit angle, so that said spurious light rays r₀ are reflected towards the rear/inner face 10i of plate-like body 10.
The secondary light-entry surface(s) 11b of the refractive prisms 11, on the other hand, are placed downstream and behind the main light-entry surfaces 11a with reference to the direction d₁, so as to be covered and shaded by the same main light-entry surfaces 11a and thus not being reachable by the light rays r of light beam f.
In more detail, the secondary light-entry surface(s) 11b of the refractive prisms 11 are preferably oriented so as to be locally substantially parallel to the direction d₁, so as not to be reachable by the light rays r belonging to the light beam f.
Even in more detail, in the example shown the secondary light-entry surface(s) 11b of the various refractive prisms 11 are preferably substantially parallel to the generatrix line of the light cone formed by the light beam f collimated or quasi-collimated in direction d₁.
In other words, the secondary light-entry surface(s) 11b of each refractive prism 11 are preferably inclined with respect to the direction d₁ by an angle γ substantially equal to half the opening angle α of the light beam f.
Clearly the tilt angle γ may also be greater than half the opening angle α of the light beam f.
Preferably, the secondary light-entry surface(s) 11b of each refractive prism 11 are therefore arranged in undercut with respect to the main light-entry surface 11a of the same prism, so as to not be struck by the light rays r belonging to the light beam f.
Optionally, the secondary light-entry surface(s) 11b of each refractive prism 11 are furthermore shaped so as to deflect the incident spurious light rays r₀ towards the reflective surface 12b of at least one corresponding refractor prism 12 present on the front/outer face 10e of plate-like body 10, with an angle of incidence greater than or equal to the limit angle, such that the spurious light rays r₀ are reflected back toward the rear/inner face 10i of the plate-like body 10.
With reference to Figures 1 and 2, preferably the automotive light 1 finally also comprises an opaque shielding mask 13, substantially rigid and preferably also with a plate-like structure, which is arranged immediately beneath the front half-shell 3, i.e. between the plate-like body 10 and the front half-shell 3, so as conceal from view the rest of the components of the automotive light, including the lighting assembly 4, and is provided with one or more limited light-passage areas 13a of predetermined shape, each of which allows the light coming from the corrective optics of the plate-like body 10 to freely reach the front half-shell 3.
Preferably, the light-passage area(s) 13a of the opaque shielding mask 13 furthermore consist of pass-through openings with predetermined shape.
In the example shown, in particular, the opaque shielding mask 13 is preferably substantially complementary in shape to that of the mouth of rear body 2, and is preferably made of opaque plastic material advantageously via injection moulding.
Clearly, the limited light-passage area(s) of the opaque shielding mask 13 may also consist of sectors of the mask made of transparent or semi-transparent plastic material, possibly even coloured.
General operation of automotive light 1 is easy inferable from what written above, and does not require further explanation.
The operation of lighting assembly 4, on the other hand, will be described with reference to a single collimated or quasi-collimated light beam f, i.e. with reference to a single concave reflective surface 6a of reflector body 6.
The light rays r of light beam f coming from the collimated or quasi-collimated light source 5, or rather from the concave reflective surface 6a of reflector body 6, reach the rear/inner face 10i of plate-like body 10 at the main light-entry surfaces 11a of the various refractive prisms 11, with an angle of incidence lower than the limit angle.
Consequently, the light rays r of light beam f freely enter into the plate-like body 10 undergoing, at the main light-entry surfaces 11a of the refractive prisms 11, a first deflection/refraction that directs them towards the light-exit surface(s) 12a of the refractive prisms 12 present on the front/outer face 10e of the plate-like body 10.
The light rays r of light beam f then continue inside the plate-like body 10 up to reach the light-exit surfaces 12a of the refractive prisms 12 present on the front/outer face 10e, from where they come out from the plate-like body 10 undergoing a second deflection/refraction that preferably arranges them more or less parallel to the direction d₂.
The light rays r of light beam f coming from the collimated or quasi-collimated light source 5, or rather from reflector body 6, instead cannot intersect the secondary light-entry surfaces 11b of the refractive prisms 11 present on the rear/inner face 10i of the plate-like body 10, because they are covered by the main light-entry surfaces 11a of the same refractive prisms 11.
In turn, the light rays r₀ that are not collimated or quasi-collimated in the direction d₁ (these spurious light rays may be, for example, external to the light beam f or may come from other concave reflective surfaces 6a of reflector body 6), can theoretically reach any point of the rear/inner face 10i of the plate-like body 10, including the main light-entry surfaces 11a and the secondary light-entry surfaces 11b of the refractive prisms 11.
If they reach the rear/inner face 10i of plate-like body 10 at the main light-entry surfaces 11a of the refractive prisms 11, the spurious light rays r₀ penetrate inside the plate-like body 10 and undergo, at the primary light-entry surfaces 11a of the refractive prisms 11, a first deflection/ refraction that directs them towards the reflective surfaces 12b of the refractive prisms 12 present on the front/outer face 10e of plate-like body 10.
Once entered into the plate-like body 10 at the main light-entry surfaces 11a, therefore, the spurious light rays r₀ continue up to reach the reflective surfaces 12b of the refractive prisms 12 present on the front/outer face 10e of plate-like body 10, where, having an angle of incidence greater than the limit angle, they are reflected towards the rear/inner face 10i of plate-like body 10.
Once the rear/inner face 10i of the plate-like body 10 is reached again, the spurious light rays r₀ may advantageously come out from the plate-like body 10 directed towards the rear body 2 and/or towards the collimated or quasi-collimated light source 5.
If, on the other hand, they reach the rear/inner face 10i of plate-like body 10 at the secondary light-entry surfaces 11b of the refractive prisms 11, the spurious light rays r₀ freely penetrate inside the plate-like body 10 and undergo, at the secondary light-entry surfaces 11b of the refractive prisms 11, a first deflection/refraction that advantageously directs them towards the reflective surfaces 12b of the refractive prisms 12 present on the front/outer face 10e of plate-like body 10.
Once entered into the plate-like body 10 at the secondary light-entry surfaces 11b, therefore, the spurious light rays r₀ may eventually continue up to reach the reflective surfaces 12b of the refractive prisms 12 present on the front/outer face 10e of plate-like body 10, where, having an angle of incidence greater than the limit angle, they are reflected towards the rear/inner face 10i of plate-like body 10.
Also in this case, once the rear/inner face 10i of the plate-like body 10 is reached again, the spurious light rays r₀ may advantageously come out from the plate-like body 10 directed towards the rear body 2 and/or towards the collimated or quasi-collimated light source 5.
The advantages resulting from the particular structure of the corrective optics of plate-like body 10 are remarkable.
Experimental tests have highlighted that the anomalies in the spatial distribution of the light on exit from the automotive light are mainly caused by the spurious light rays r₀, i.e. by the light rays external to the light beam f.
The particular shape of the refractive prisms 11, 12 present on the inner 10i and outer 10e faces of the plate-like body 10 prevents most of the spurious light rays r₀ from reaching the front half-shell 3, thus minimizing the intensity of the light coming out from the automotive light with a direction strongly inclined with respect to the optical axis A.
In other words, the particular shape of the corrective optics of plate-like body 10 prevents the front half-shell 3 from unexpectedly "turning on" when the observer moves towards the outer side of the vehicle body.
In addition, the particular shape of the refractive prisms 11, 12 present on the inner 10i and outer 10e faces of plate-like body 10 increases the optical efficiency of the automotive light 1, transferring to the high brightness area located at the optical axis A of the automotive light, a greater percentage of the overall light energy emitted by the collimated or quasi-collimated light source 5.
This means that it is possible to obtain, on exit of the automotive light 1, a luminous flow with intensity and distribution of the light that complies with the approval regulations, using less powerful LEDs 9.
It is finally clear that modifications and variations may be made to the automotive light 1 and/or to the lighting assembly 4 described above without however departing from the scope of the present invention.
For example, as an alternative the collimated or quasi-collimated light source 5 may comprise: an electrically-powered light emitting device which emits light on command and is arranged inside the rear body 2, so as to direct the produced light towards the corresponding transparent or semi-transparent sector of the front half-shell 3; and a Fresnel lens, which is interposed between the light emitting device and the plate-like body 10, preferably spaced from both, so as to be crossed by and to collimate or quasicollimate the light beam directed towards the front half-shell 3.

Claims

Automotive light (1) comprising: a rear body (2) adapted to be fixed on the vehicle; a front half-shell (3) arranged to close the mouth of said rear body (2); and at least one lighting assembly (4), which is located inside the rear body (2) and is adapted to backlight a corresponding transparent or semi-transparent sector of the front half-shell (3);
said lighting assembly (4) comprising: a collimated or quasi-collimated light source (5) that produces and directs towards the front half-shell (3) at least one light beam (f) collimated or quasi-collimated in a predetermined first direction (d₁); and a corrective optics (10) with plate-like structure, which is interposed between the collimated or quasi-collimated light source (5) and the front half-shell (3), and is adapted to deflect said light beam (f) in a second direction (d₂) inclined with respect to said first direction (d₁).

said automotive light (1) being characterized in that the corrective optics (10) is structured so as reflect, towards the rear body (2) and/or towards the collimated or quasi-collimated light source (5), at least a part of the spurious light rays (r₀) that reach the inner face (10i) of the corrective optics (10) and do not belong to said light beam (f) .
Automotive light according to Claim 1, wherein the inner face (10i) of said corrective optics (10) is provided with at least a first embossed portion which has a complex three-dimensional structure and forms a plurality of first refractive prisms (11), and the outer face (10e) of said corrective optics (10) is provided with at least a second embossed portion that has a complex three-dimensional structure and forms a plurality of second refractive prisms (12); said second refractive prisms (12) being provided with a light-exit surface (12a) and with at least one reflective surface (12b) contiguous and inclined with respect to said light-exit surface (12a); said first refractive prisms (11) being provided with a main light-entry surface (11a) that faces the collimated or quasi-collimated light source (5) and is adapted to deflect the light rays (r) of said light beam (f) towards the light-exit surface (12a) of one or more of said second refractive prisms (12) with an angle of incidence lower than the limit angle, so as to let the same light rays (r) come out from the outer face (10e) of the corrective optics (10), and with at least one secondary light-entry surface (11b) contiguous and inclined with respect to said main light-entry surface (11a), which is not reachable by the light rays (r) belonging to said light beam (f) .
Automotive light according to Claim 2, wherein the secondary light-entry surfaces (11b) of the first refractive prisms (11) are arranged downstream and behind the main light-entry surfaces (11a) with reference to said first direction (d₁).
Automotive light according to Claim 2 or 3, wherein the main light-entry surfaces (11a) of the first refractive prisms (11) are convex and/or are substantially perpendicular to said first direction (d₁).
Automotive light according to Claim 2, 3 or 4, wherein the main light-entry surface (11a) of the first refractive prisms (11) is moreover adapted to deflect at least a part of the spurious and incident light rays (r₀) towards the reflective surface (12b) of one or more of said second refractive prisms (12), with an angle of incidence greater than the limit angle, so that the same spurious light rays (r₀) are reflected towards the inner face (10i) of the corrective optics (10).
Automotive light according to any one of Claims 2 to 5, wherein the secondary light-entry surface or surfaces (11b) of the first refractive prisms (11) are adapted to deflect at least a part of said spurious and incident light rays (r₀) towards the reflective surface (12b) of one or more of said second refractive prisms (12), with an angle of incidence greater than the limit angle, so that the same spurious light rays (r₀) are reflected towards the inner face (10i) of the corrective optics (10).
Automotive light according to any one of Claims 2 to 7, wherein the secondary light-entry surfaces (11b) of the first refractive prisms (11) are substantially flat and/or are substantially parallel to said first direction (d₁), so that they are not reachable by the light rays (r) belonging to said light beam (f).
Automotive light according to Claim 7, wherein said light beam (f) has an opening angle (α) of predetermined size, and the secondary light-entry surfaces (11b) of the first refractive prisms (11) are inclined with respect to said first direction (d₁) by an angle greater than or equal to half of said opening angle (α).
Automotive light according to any one of Claims 2 to 8, wherein the light-exit surfaces (12a) of said second refractive prisms (12) are shaped so that the light rays (r) that belong to said light beam (f) and exit from the outer face (10e) of said corrective optics (10), are also collimated or quasi-collimated in a direction substantially parallel to said second direction (d₂).
Automotive light according to any one of the preceding Claims, wherein said collimated or quasi-collimated light source (5) is structured so as produce and direct, towards the front half-shell (3), a plurality of light beams (f) separated and distinct from each other, each of which is directed towards a corresponding portion of the front half-shell (3) and is collimated or quasi-collimated in a corresponding predetermined first direction (d₁).
Automotive light according to any one of the preceding Claims, wherein said collimated or quasi-collimated light source (5) comprises: a reflector body (6) provided with at least one concave reflective surface (6a) oriented so as reflect the incident light towards the front half-shell (3); and an electrically-powered light emitting device (7), which emits light on command and is arranged by the side of the reflector body (6), so as to direct the produced light towards the concave reflective surface (6a) of the reflector body (6); said at least one concave reflective surface (6a) being shaped so as reflect, towards the front half-shell (2), the light coming from the light emitting device (7), while forming said light beam (f) collimated or quasi-collimated in said first direction (d₁).
Automotive light according to Claim 11, wherein said at least one concave reflective surface (6a) has a substantially semi-parabolic profile.
Automotive light according to Claim 11 or 12, wherein the light emitting device (7) has a plate-like structure.
Automotive light according to Claim 11, 12 or 13, wherein the light emitting device (7) comprises one or more LEDs (9).
Automotive light according to any one of the preceding Claims, wherein the tilt angle (β) between said first direction (d₁) and said second direction (d₂) ranges between 0° and 50°.
Automotive light according to any one of the preceding Claims, wherein the automotive light (1) is a headlight or taillight for cars and the like.