Automotive lighting device and related control method

Abstract

A car lighting device (1) comprises: a rear body (2) adapted to be fixed to the outside or inside of a vehicle; a front half-shell (3) arranged to close an opening of the rear body (2); at least one lighting assembly (4) located inside the rear body (2) and adapted to backlight a corresponding transparent or translucent portion of the front half-shell (3) according to an instruction; the lighting assembly (4) comprises: a radial emitting optical fiber (6) of a given length; an electric collimating light source (5) located in front of a proximal end (6a) of the optical fiber (6) and adapted to direct a collimated light beam (r) entering the optical fiber (6) and propagating therein towards the proximal end (6a); at least one proximal photometric sensor (8) arranged beside the collimating light source (5) and / or the proximal end (6a) of the optical fiber (6) to capture / detect light reflected / scattered when entering the optical fiber (6); at least one distal photometric sensor (9) arranged in front of a distal end (6b) of the optical fiber (6) and adapted to capture / detect light exiting the distal end (6b) of the optical fiber (6); and an electronic control unit (7) adapted to control the collimating light source (5) based on signals from the proximal and distal photometric sensors (8, 9).

Description

[0001] Cross-references to related applications

[0002] This application claims priority to European Patent Application No. 19219036.1, filed on 20 December 2019, European Patent Application No. 20201140.9, filed on 9 October 2020, and European Patent Application No. 20203958.2, filed on 26 October 2020, the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] This invention relates to an automotive lighting device and its control method.

[0004] More specifically, the present invention relates to a headlight or taillight for passenger cars and similar vehicles, i.e., a lighting device suitable for integration into a motor vehicle, having the function of indicating position, sudden deceleration, and / or turning direction, and / or having the function of illuminating the area around the vehicle. The following disclosure expressly references this application, but without thereby diminishing its generality. Background Technology

[0005] As is well known, taillights used in cars generally include: a rigid, roughly basin-shaped rear body that is stably recessed into a compartment specifically located in the rear of the vehicle body; a front housing that is configured to close the opening of the rear body in a manner that exposes it to the outside of the vehicle body, and generally has multiple transparent or semi-transparent sections that are usually different colors from each other; and a series of lighting components located within the rear body, each immediately below a corresponding transparent or semi-transparent section of the front housing, thereby enabling selective backlighting of the transparent or semi-transparent section of the front housing covering it.

[0006] Typically, each transparent or semi-transparent section of the front housing is also uniquely associated with a specific light signal suitable for notifying the vehicle's position, sudden deceleration, or direction of steering during driving. Therefore, each lighting component is specifically configured to emit a beam of light that, upon exiting the taillight through the corresponding transparent or semi-transparent section of the housing, conforms to the approved specifications (color and light distribution) required by the corresponding light signal.

[0007] In recent years, some car manufacturers have opted to equip their new models with taillights that feature one or more transparent or translucent, rectangular and strip-shaped sections (i.e., with a narrow and very elongated shape) in the front half of the housing.

[0008] The illumination assembly that backlights the single transparent or translucent band of the front half-shell generally comprises a light guide bar made of polymethyl methacrylate (PMMA) or other light guide material and extending within the rear body to sweep over the band to be backlit, preferably over the entire length of the band, and one or more high-power LEDs (acronym for Light Emitting Diodes) fixed on a small printed circuit board in turn positioned within the rear body close to at least one of the two ends of the light guide bar so that the LED(s) abut against the end of the light guide bar and can direct light directly into the body of the light guide bar.

[0009] The light then propagates within the body of the light guide bar by total internal reflection and gradually exits from the side of the light guide bar directly facing the front half-shell, thus enabling backlighting of the transparent or translucent part of the half-shell that covers it.

[0010] Despite its effectiveness, the backlighting system of the band of the front half-shell makes the assembly of the tail light relatively cumbersome.

[0011] Indeed, the light guide bar is well known to be a solid and rigid but relatively fragile monolithic body, which must therefore be inserted into the rear body with great care. In addition, the aforementioned end or both ends of the light guide bar must be perfectly aligned with the LEDs to avoid light leakage, which lengthens the assembly time of the headlamp.

[0012] To simplify and speed up the assembly of the automotive light, some manufacturers of the headlights for cars and the like have recently replaced the light guide bar of the illumination assembly with a radial emitting optical fiber, which is well known to be more flexible than the light guide bar made of polymethyl methacrylate (PMMA).

[0013] At the same time, the high-power LED(s) has been replaced by a small laser emitter mechanically coupled to one of the two ends of the radial emitting optical fiber by a fixing collar that holds the end of the optical fiber in place in front of the laser emitter.

[0014] Unfortunately, despite its effectiveness, it turns out that this new type of illumination assembly can be very dangerous in the event of a breakage of the tail light after a car accident.

[0015] Indeed, experimental tests have shown that, in the event of a breakage of the front half-shell of the headlight, the optical fiber breaks and moves out of its seat, thus freeing the laser light that exits the headlight, creating all the safety problems that derive therefrom.

[0016] Indeed, the laser beam emitted by the laser emitter of the headlight generally has an intensity that permanently damages the human eye, and a broken and freely moving optical fiber can in theory accidentally direct the laser light outside the headlight towards the human eye that is resting inside the vehicle or immediately adjacent to the vehicle, thus causing personal injury. SUMMARY

[0017] The object of the present application is to improve the active safety of a new lighting assembly for back-lighting a front half-shell of a fiber-optic reading light.

[0018] In order to achieve these objects, according to the present application there is provided an automotive lighting device comprising: a rear body adapted to be fixed to a vehicle; a front half-shell arranged to close an opening of the rear body; and at least one lighting assembly located inside the rear body and adapted to back-light, upon command, a corresponding transparent or translucent portion of the front half-shell.

[0019] The lighting assembly comprises: a radial emitting optical fiber of a given length; and an electrically powered collimated light source located in front of a proximal end of the optical fiber and adapted to direct a collimated light beam towards the proximal end, the collimated light beam entering the optical fiber and propagating inside the optical fiber.

[0020] The lighting device is characterized in that the lighting assembly further comprises: at least one proximal photometric sensor arranged beside the collimated light source and / or the proximal end of the optical fiber to capture / detect light reflected / scattered upon entering the optical fiber; at least one distal photometric sensor arranged in front of a distal end of the optical fiber and adapted to capture / detect light exiting from the distal end of the optical fiber; and an electronic control unit adapted to control the collimated light source based on signals from the proximal and distal photometric sensors.

[0021] According to the present application there is provided an automotive lighting device having a lighting assembly and characterized in that the lighting assembly comprises: a radial emitting optical fiber of a given length; a collimated light source arranged in front of a proximal end of the optical fiber and adapted to direct a collimated light beam towards the proximal end, the collimated light beam entering the optical fiber and propagating inside the optical fiber; at least one proximal photometric sensor arranged beside the collimated light source and / or the proximal end of the optical fiber to capture / detect light reflected / scattered upon entering the optical fiber; at least one distal photometric sensor arranged in front of a distal end of the optical fiber and adapted to capture / detect light exiting from the distal end of the optical fiber; and an electronic control unit adapted to control the collimated light source based on signals from the proximal and distal photometric sensors.

[0022] According to the present application there is also provided a control method for a motor vehicle lighting device having an illumination assembly comprising: a radial emitting optical fiber of a given length; a collimated light source arranged in front of the proximal end of the optical fiber and adapted to direct a collimated light beam towards the proximal end, the collimated light beam entering the optical fiber and propagating within the optical fiber; at least one proximal photometric sensor arranged beside the collimated light source and / or the proximal end of the optical fiber, to capture / detect light reflected / scattered when entering the optical fiber; at least one distal photometric sensor arranged in front of the distal end of the optical fiber and adapted to capture / detect light exiting from the distal end of the optical fiber.

[0023] The control method is characterized in that it comprises the steps of:

[0024] - determining the intensity of light reflected / scattered outside the optical fiber at the proximal end thereof, as a function of the signal from the at least one proximal photometric sensor;

[0025] - determining the intensity of light exiting from the distal end of the optical fiber, as a function of the signal from the at least one distal photometric sensor; and

[0026] - switching off / deactivating the collimated light source as a function of the intensity of light detected by the at least one proximal photometric sensor and / or the intensity of light detected by the at least one distal photometric sensor. BRIEF DESCRIPTION OF DRAWINGS

[0027] The application will now be described with reference to the accompanying drawings, which show non-limiting embodiments thereof, in which:

[0028] Figure 1 is a perspective view, partially exploded, of a motor vehicle lamp, according to the teachings of the present application, with some parts removed for the sake of clarity;

[0029] Figure 2 is Figure 1 an exploded perspective view of the back lighting system of the motor vehicle lamp shown, with some parts removed for the sake of clarity;

[0030] Figure 3 is Figure 1 a cross-sectional view of a portion of the motor vehicle lamp of

[0031] Figure 4 is a cross-sectional view, partially exploded, of the coupling system between the laser emitter and the optical fiber of one of the illumination assemblies arranged in the headlamp shown in the previous figures, with some parts removed for the sake of clarity;

[0032] Figure 5 is Figure 1 , Figure 2 and Figure 3schematic view of the electronic equipment of one of the lighting assemblies provided in the headlamp shown, with parts removed for clarity;

[0033] Figure 6 is a front view of a car door provided with a lighting device implemented according to the teachings of the present application, with parts removed for clarity; and

[0034] Figure 7 is a view of the car door along the section plane line V-V Figure 6 is a partial side view of the car door shown, with parts removed for clarity. DETAILED DESCRIPTION

[0035] With reference to Figure 1 , Figure 2 and Figure 3 , reference 1 generally indicates a lighting device for automotive use, i.e. a lighting device suitable for being installed in a motor vehicle.

[0036] More in detail, the lighting device 1 is preferably a car light, i.e. a lighting device particularly suitable for being placed in the front or rear portion of the body of a motor vehicle, having the function of emitting light signals suitable for giving notice of the position of the vehicle during travel and / or of the sudden slowing of the vehicle and / or of the direction of the turning of the vehicle.

[0037] In other words, the lighting device 1 is suitable for being fixed to the front or rear portion of the body of a car, van, truck, motorcycle or other similar motor vehicle, to perform the function of a headlight or of a tail light.

[0038] Preferably, the lighting device 1 is also configured to be exposed to the outside of the vehicle.

[0039] In particular, in the example shown, the lighting device 1 is preferably configured to be stably sunk into the rear portion of the body of a car or other similar motor vehicle.

[0040] In other words, the lighting device 1 is preferably a tail light for cars and the like.

[0041] Obviously, in different embodiments, the lighting device 1 can also be configured to be simply fixed in a cantilevered manner to the front or rear portion of the body of the vehicle (not shown).

[0042] With reference to Figure 1 , Figure 2 and Figure 3 , the lighting device 1 first comprises a rear body 2, substantially rigid and preferably made of plastic material, suitable for being firmly fixed to the vehicle, preferably externally to the vehicle, and a front half-shell 3, generally known as a lens, substantially rigid and preferably made of plastic material, arranged to close the opening of the rear body 2, preferably being able to be exposed externally to the body of the vehicle.

[0043] More in detail, the rear body 2 is preferably substantially basin-shaped and is preferably configured to be at least partially housed in a seat specially formed in the rear of the body of the vehicle (not shown).

[0044] Obviously, in different embodiments, the rear body 2 can also be configured to be simply fixed in a cantilevered manner to the rear of the body of the vehicle (not shown).

[0045] In addition, the lighting device 1 also comprises one or more electric lighting assemblies which emit light on command and are housed inside the rear body 2, each of which is positioned below a respective transparent or translucent portion of the front half-shell 3, so as to be able to selectively backlight the transparent or translucent portion of the front half-shell 3 which overlies it.

[0046] More in detail, in the example shown, the rear body 2 is preferably made of an opaque plastic material, preferably by means of an injection molding process.

[0047] On the other hand, the front half-shell 3 is preferably made of a transparent or translucent plastic material, such as polycarbonate (PC) or polymethyl methacrylate (PMMA), in this case also preferably by means of an injection molding process.

[0048] Furthermore, in the example shown, the lighting device 1 is preferably provided with a plurality of electric lighting assemblies, each of which is positioned inside the rear body 2 in such a way as to be able to backlight only the corresponding transparent or translucent portion of the front half-shell 3 which overlies it, preferably separate and independent from the other lighting assemblies of the lighting device.

[0049] With reference to Figure 1 , Figure 2 , Figure 3 and Figure 4 , at least one lighting assembly, hereinafter indicated with the reference number 4, also comprises a laser source 5 which is arranged inside the rear body 2 and is able to emit a laser beam r (i.e. a very concentrated and collimated, coherent monochromatic light beam) on command, and a filamentary structure of given length and preferably with flexibility, of an optical fiber 6 which extends inside the rear body 2 and one of the two ends thereof, hereinafter called the proximal end, faces and is optically coupled with the laser source 5 in such a way that the laser beam r emitted by the laser source 5 can freely enter the optical fiber 6 and propagate inside it.

[0050] In addition, the lighting assembly 4 also comprises an electronic control unit 7 which controls the laser source 5, preferably housed inside the rear body 2, optionally close to the bottom of the latter. The electronic control unit 7 is adapted to activate and deactivate the laser source 5 on the basis of an external command signal.

[0051] In other words, the external command signal controls the emission of the laser beam r.

[0052] In addition, the optical fiber 6 is specifically configured so as to enable the laser light propagating therein to gradually diverge preferably substantially along its entire length. In other words, the optical fiber 6 is a radial emitting optical fiber.

[0053] In more detail, the optical fiber 6 has a proximal end portion 6a and a distal end portion 6b opposite the proximal end portion 6a.

[0054] The laser source 5 is arranged inside the rear body 2, facing the proximal end portion 6a of the optical fiber 6, and is adapted to emit a laser beam r according to an instruction and towards the proximal end portion 6a, which enters the optical fiber 6 and propagates inside the optical fiber 6 towards the distal end portion 6b.

[0055] In more detail, the proximal end portion 6a of the optical fiber 6 is arranged at a distance d in front of the emitter of the laser source 5, which distance is preferably less than or equal to 0.5 mm (millimeters), more suitably between 0.1 and 0.3 mm (millimeters).

[0056] The optical fiber 6, in turn, is specifically configured so as to direct the incoming laser light towards its own distal end portion 6b, while enabling a predetermined percentage of the laser light to gradually diverge substantially in a radial direction outside the optical fiber 6 as the light propagates inside the optical fiber 6.

[0057] In addition, the lighting assembly 4 further comprises at least one proximal photodetector 8 arranged beside the emitter of the laser source 5 and / or the proximal end portion 6a of the optical fiber 6, so as to capture / detect the laser light reflected / scattered outside the optical fiber 6 as the laser beam r enters the proximal end portion 6a of the optical fiber 6, and at least one distal photodetector 9 placed in front of the distal end portion 6b of the optical fiber 6 and adapted to capture / detect the laser light exiting from the distal end portion 6b of the optical fiber 6.

[0058] The electronic control unit 7, in turn, is adapted to control the laser source 5 on the basis of the signals coming from the proximal photodetector 8 and the distal photodetector 9.

[0059] In more detail, the electronic control unit 7 is preferably programmed / configured to autonomously deactivate the laser source 5 when the ratio between the intensity of the light reflected / scattered outside the optical fiber 6 at the proximal end portion 6a of the optical fiber and the intensity of the light exiting from the distal end portion 6b of the optical fiber deviates from a predetermined reference value, so as to interrupt / stop the emission of the laser beam r.

[0060] Obviously, said reference value is a construction parameter which varies as a function of the structural characteristics of the optical fiber 6, such as the length of the optical fiber and / or the radial emission / divergence coefficient of the optical fiber.

[0061] Preferably, said reference value is also stored inside the electronic control unit 7.

[0062] In other words, the electronic control unit 7 is preferably programmed / configured to autonomously deactivate the laser source 5, to interrupt / prevent the emission of the laser beam r, when the ratio between the intensity of the laser detected by the proximal photodetector 8 and the intensity of the laser detected by the distal photodetector 9 deviates from said predetermined reference value.

[0063] With reference to Figure 1 , Figure 2 and Figure 3 , in particular, in the example shown, the front half-shell 3 preferably has at least one transparent or translucent portion 3a (in the example shown, two portions), which has a narrow and elongated shape, i.e. is substantially strip-shaped.

[0064] The illumination assembly 4 suitable for selectively back-illuminating said / each transparent or translucent strip-shaped portion 3a of the front half-shell 3 preferably comprises: a radially emitting optical fiber 6, which extends inside the rear shell 2 so that at least a portion / section of the optical fiber substantially locally skims the strip-shaped portion 3a to be back-illuminated, preferably substantially skims the entire length of the strip-shaped portion 3a; and an electrically powered laser source 5, capable of emitting a laser beam r on command, and arranged inside the rear body 2 so as to directly face and be aligned with a proximal end portion 6a of the optical fiber 6, so that the laser beam r emitted from the emitter of the laser source 5 can freely enter the optical fiber 6 through said proximal end portion 6a.

[0065] Furthermore, preferably, the optical fiber 6 has an outer diameter of less than 5 mm (millimeters), and more suitably less than 1.2 mm (millimeters).

[0066] Furthermore, with reference to Figure 1 , Figure 2 and Figure 3 , the optical fiber 6 is also preferably held / supported by a rigid carrier structure, which is integral with the rear body 2 and is preferably made of plastic material.

[0067] More in detail, the optical fiber 6 is preferably fixed on a front side portion of a rigid support plate 10, which is arranged inside the rear body 2, whose front side portion directly faces the front half-shell 3, more precisely preferably substantially on the entire length of the corresponding strip-shaped portion 3a, and whose rear side portion faces the bottom of the rear body 2. Obviously, the support plate 10 can also project in cantilevered manner from the bottom of the rear body 2.

[0068] Furthermore, with reference to Figure 2 and Figure 4, the lighting assembly 4 also preferably comprises centring and fixing mechanical means 11 suitable for rigidly connecting the proximal end 6a of the optical fibre 6 to the laser source 5, more precisely to the emitter of the laser source 5, and configured to stably keep the proximal end 6a of the optical fibre 6 centred and fixed in front of the emitter of the laser source 5.

[0069] More in detail, the centring and fixing means 11 are preferably configured to keep the proximal end 6a of the optical fibre 6 fixed in front of the emitter of the laser source 5 at a distance d smaller than 0.5 mm, preferably comprised between 0.1 and 0.3 mm.

[0070] In the example shown, in particular, the centring and fixing means 11 are preferably configured to stably keep the proximal end 6a of the optical fibre 6 at a distance d comprised between 0.2 and 0.25 mm from the emitter of the laser source 5.

[0071] The electronic control unit 7 is in turn programmed / configured to activate and deactivate the laser source 5 on the basis of an external command signal. In addition, the electronic control unit 7 is preferably also programmed / configured to automatically deactivate the laser source 5 when the ratio between the intensity of the laser light detected by the proximal photodetector 8 and the intensity of the laser light detected by the distal photodetector 9 moves outside a predetermined tolerance interval, which crosses said reference value and is preferably also substantially centred on said reference value.

[0072] More in detail, in the example shown, the electronic control unit 7 is preferably programmed / configured to automatically deactivate the laser source 5 when the ratio between the intensity of the laser light detected by the proximal photodetector 8 and the intensity of the laser light detected by the distal photodetector 9 moves away from / deviates from said reference value by 10%.

[0073] In other words, in the example shown, the tolerance interval preferably has a width equal to 20% of said reference value and is preferably also centred on this reference value.

[0074] With reference to Figure 2 , Figure 4 and Figure 5 , preferably, the lighting assembly 4 also comprises at least one temperature sensor 12 suitable for continuously detecting the temperature of the laser source 5, more precisely the temperature of the emitter of the laser source 5.

[0075] In addition, the electronic control unit 7 is preferably also connected to the temperature sensor 12 and is suitable for amplifying the signal from the proximal photodetector 8 and / or the signal from the distal photodetector 9 as a function of the current temperature of the laser source 5, more precisely as a function of the current temperature of the emitter of the laser source 5.

[0076] In more detail, the electronic control unit 7 is preferably programmed / configured to increase the power / intensity of the signal from the proximal photodetector 8 and / or the power / intensity of the signal from the distal photodetector 9 as the temperature reached by the laser source 5, more precisely the temperature reached by the emitter of the laser source 5, increases.

[0077] In more detail, in the example shown, the electronic control unit 7 is preferably programmed / configured to amplify the signal from the proximal photodetector 8 and the signal from the distal photodetector 9 with substantially the same amount of gain as the temperature of the laser source 5 increases.

[0078] With reference to Figure 2 , Figure 3 , Figure 4 and Figure 5 , in the example shown, in particular, the laser source 5 preferably comprises: a laser diode 13 suitable for emitting a laser beam; and a driving module 14 which powers and / or controls the laser diode 13.

[0079] Obviously, the laser diode 13 is the emitter of the laser source 5.

[0080] In addition, the lighting assembly 4 is preferably provided with at least two proximal photodetectors 8 which are placed next to the emitter of the laser source 5, more precisely the laser diode 13, on opposite sides of the latter and preferably substantially in mirror-symmetrical positions with respect to the latter.

[0081] In addition, the distance between the emitter of the laser source 5, more precisely the laser diode 13, and the two proximal photodetectors 8 is preferably less than or equal to 10 mm (millimetres) and more suitably between 1 and 8 mm (millimetres).

[0082] Furthermore, preferably, the proximal photodetector(s) 8 and the laser source 5, more precisely the emitter of the laser source 5, are placed / fixed next to each other on a small printed circuit board 15 which in turn is placed / fixed inside the rear body 2 of the lighting device close to the proximal portion 6a of the optical fibre 6.

[0083] In addition, the temperature sensor 12 is preferably provided on the printed circuit board 15 in contact with or in any case close to the emitter of the laser source 5, more precisely the laser diode 13.

[0084] In particular, in the example shown, the photodetectors 8 and / or 9 are preferably photodiodes.

[0085] On the other hand, the laser diode 13 is preferably a red or RGB laser diode capable of emitting a laser beam with variable power and / or colour on command.

[0086] Obviously, the reference value for automatically switching off the laser source 5 can also vary as a function of the color of the laser beam r emitted by the laser source 5.

[0087] With reference to Figure 5 On the other hand, the electronic control unit 7 preferably comprises a microprocessor 16 which receives at the input external command signals and signals from the photometric sensors 8 and 9 and is adapted to control the driving module 14 of the laser source 5 as a function of these signals.

[0088] More in detail, the microprocessor 16 is preferably programmed / configured to control the driving module 14 to activate / energize the laser diode 13 to emit the laser beam r only when the external command signals require switching on the lighting assembly 4.

[0089] In addition, the microprocessor 16 is also preferably programmed / configured to command the driving module 14 to immediately switch off / deactivate the laser diode 13 when the ratio between the intensity of the light detected by the proximal photometric sensor(s) 8 and the intensity of the light detected by the distal photometric sensor 9 greatly deviates from said predetermined reference value.

[0090] More in detail, the microprocessor 16 is preferably programmed / configured to command the driving module 14 to immediately switch off / deactivate the laser diode 13 when the amount of deviation of the ratio between the intensity of the light detected by the proximal photometric sensor(s) 8 and the intensity of the light detected by the distal photometric sensor 9 from said reference value is greater than a limit threshold, preferably equal to 10% of the reference value.

[0091] More in detail, the microprocessor 16 is preferably programmed / configured to continuously or cyclically determine the intensity of the light reflected / diffused outside the optical fiber at the proximal portion 6a of the optical fiber 6 on the basis of the signals from the proximal photometric sensor(s) 8 and the intensity of the light exiting from the distal portion 6b of the optical fiber on the basis of the signals from the distal photometric sensor 9.

[0092] After having determined the current value of the intensity of the light reflected / diffused outside the optical fiber at the proximal portion 6a of the optical fiber and the current value of the intensity of the light exiting from the distal portion 6b of the optical fiber, the microprocessor is preferably programmed / configured to calculate the current ratio between the intensity of the light reflected / diffused outside the optical fiber at the proximal portion 6a of the optical fiber and the intensity of the light exiting from the distal portion 6b of the optical fiber.

[0093] After calculating the current value of the ratio between the intensity of the light reflected / diffused outside the optical fiber at the proximal end 6a thereof and the intensity of the light exiting from the distal end 6b of the optical fiber, the microprocessor 16 is preferably programmed / configured to command the driving module 14 to immediately switch off / inactivate the laser diode 13 when the difference between the predetermined reference value and the instantaneous value of the ratio between the intensity of the light reflected / diffused outside the optical fiber at the proximal end 6a thereof and the intensity of the light exiting from the distal end 6b of the optical fiber exceeds said limit threshold value.

[0094] With reference to Figure 5 Preferably, the electronic control unit 7 also comprises, for each of the photometric sensors 8 and 9, a signal amplifier 17 interposed between the microprocessor 16 and the corresponding photometric sensor 8, 9 and suitable to amplify, i.e. to increase the power / intensity of, the signal directed to the microprocessor 16.

[0095] In addition, the microprocessor 16 also receives, at the input, the signal from the temperature sensor 12 and is preferably suitable to control the signal amplifier 17 as a function of this signal.

[0096] In greater detail, the microprocessor 16 is preferably programmed / configured to adjust the amount of gain of the signal amplifier 17 as a function of the signal from the temperature sensor 12.

[0097] In greater detail, the microprocessor 16 is preferably programmed / configured to increase the amount of gain of the signal amplifier 17 as the temperature detected by the temperature sensor 12 increases.

[0098] With reference to Figure 4 In the example shown, finally, the mechanical centering and fixing member 11 preferably comprises: a support socket 20, rigid and preferably made of plastic or metal material, stably fixed on the printed circuit board 15 so as to act as a bridge across the emitter of the laser source 5, more precisely across the laser diode 13 and across the proximal photometric sensor(s) 8; and a ferrule connector 21, preferably made of metal material, suitable to be fitted locally coaxially to the optical fiber 6 and to be firmly locked on the proximal end 6a of the optical fiber 6.

[0099] The ferrule connector 21 is suitable to be screwed onto a threaded portion of the support socket 20, which locally aligns the emitter of the laser source 5, more precisely the laser diode 13, so as to locally and coaxially arrange the proximal end 6a of the optical fiber 6 above and spaced apart from the emitter of the laser source 5, more precisely from the laser diode 13, by a distance d.

[0100] The general operation of the automotive lighting device 1 can be easily inferred from what described above.

[0101] The operation of the alternative illumination assembly 4, the electronic control unit 7 activates and deactivates the laser source 5 on the basis of an external command signal.

[0102] Due to the air / glass interface, when the laser beam r enters the optical fiber 6 through the proximal end 6a, a small amount of light energy cannot successfully enter the optical fiber 6 and is reflected back (Fresnel reflection) towards the laser source 5 and the proximal end photodetector(s) 8. The laser light reflected towards the laser source 5 is detected by the proximal end photodetector(s) 8.

[0103] Obviously, the intensity of the laser light reflected back towards the laser source 5 is minimal and has a value proportional to the power of the laser beam r generated by the laser source 5.

[0104] In addition, if the power of the laser beam r is constant, the intensity of the laser light reflected back towards the laser source 5 remains substantially constant as long as the optical fiber 6 is perfectly aligned and coupled to the emitter of the laser source 5. Obviously, any change in the position of the proximal end 6a of the optical fiber 6 with respect to the ideal position causes a change in the intensity of the laser light detected by any of the proximal end photodetector(s) 8.

[0105] Therefore, if the power of the laser beam r is constant, any change in the light energy detected by the proximal end photodetector(s) 8 indicates a breakage of the optical fiber 6, a mispositioning of the optical fiber 6 with respect to the laser source 5, possibly due to a breakage of the lighting device 1 or to a wrong optical assembly / coupling of the optical fiber 6 with the laser source 5.

[0106] On the other hand, the distal photodetector 9 detects the intensity of the laser light exiting from the distal end 6b of the optical fiber 6. If the dimensions of the optical fiber 6 and of the laser source 5 are correctly determined, the light energy that reaches the distal end 6b of the optical fiber and spreads outside the optical fiber is minimal, but still present.

[0107] Obviously, the intensity of the laser light exiting from the distal end 6b of the optical fiber is in any case proportional to the power of the laser beam r emitted by the laser source 5.

[0108] Also in this case, if the power of the laser beam r is constant, any change in the light energy detected by the distal photodetector 9 indicates a breakage of the optical fiber 6 or a wrong positioning of the optical fiber 6 on the relative support structure, more precisely on the side of the support plate 10, possibly due to a breakage of the lighting device.

[0109] The electronic control unit 7 is programmed / configured to activate and deactivate the laser source 5 on the basis of an external command signal.

[0110] In addition, the electronic control unit 7 is programmed / configured to implement a control method comprising the following steps:

[0111] - determining the intensity of the light reflected / diffused outside the optical fiber at the proximal portion 6a of the optical fiber 6 as a function of the signal from the proximal photometric sensor(s) 8;

[0112] - determining the intensity of the light exiting from the distal portion 6b of the optical fiber 6 as a function of the signal from the distal photometric sensor 9; and

[0113] - switching off / deactivating the laser source 5 as a function of the intensity of the light detected by the proximal photometric sensor(s) 8 and / or the intensity of the light detected by the distal photometric sensor(s) 9.

[0114] More in detail, the control method preferably provides for switching off / deactivating the laser source 5 when the ratio between the intensity of the light detected by the proximal photometric sensor(s) 8 and the intensity of the light detected by the distal photometric sensor(s) 9 deviates from a predetermined reference value.

[0115] In other words, the control method implemented by the electronic control unit 7 preferably comprises the following steps:

[0116] - determining continuously or cyclically the intensity of the light reflected / diffused outside the optical fiber at the proximal portion 6a of the optical fiber 6 on the basis of the signal from the proximal photometric sensor(s) 8;

[0117] - determining continuously or cyclically the intensity of the light exiting from the distal portion 6b of the optical fiber on the basis of the signal from the distal photometric sensor 9; and

[0118] - immediately switching off / deactivating the laser source 5 when the ratio between the intensity of the light detected by the proximal photometric sensor(s) 8 and the intensity of the light detected by the distal photometric sensor(s) 9 deviates greatly from a predetermined reference value.

[0119] In the example shown, in particular, the limit threshold beyond which automatic deactivation / switching off of the laser source 5 takes place is preferably equal to 10% of the reference value.

[0120] The electronic control unit 7 prevents, by automatically deactivating the laser source 5 when the above-defined ratio deviates greatly from the reference value, damage to property and / or persons caused by the laser beam r emitted from the laser source 5 in the event of breakage or malfunction of the lighting device 1.

[0121] Preferably, the control method implemented by the electronic control unit 7 also comprises a step of measuring the temperature of the laser source 5, more precisely of the emitter of the laser source 5, and a step of amplifying the signal from the proximal photometric sensor(s) 8 and / or from the distal photometric sensor(s) 9 as a function of the temperature of the laser source 5.

[0122] In greater detail, the control method provides for increasing the power / intensity of the signal from the proximal photodetector(s) 8 and / or the distal photodetector(s) 9 as the temperature of the laser source 5, more precisely of the emitter of the laser source 5, increases.

[0123] In this way, the variations of the signal from the proximal photodetector(s) 8 and / or the distal photodetector(s) 9 due to the temperature variations of the laser source 5 are compensated.

[0124] In fact, experimental tests have shown that the power of the laser beam r emitted by the laser source 5 and, in greater detail, by the laser diode 13, generally decreases more or less randomly as the temperature of the component increases.

[0125] The advantages related to the specific structure and control method of the lighting assembly 4 described above are worth noting.

[0126] First of all, the lighting assembly 4 thus configured prevents the accidental directing of the laser beam outside the lighting device 1 in the event of breakage or incorrect positioning of the optical fiber 6.

[0127] In greater detail, the presence of the photodetectors 8 and 9 makes it possible to control in real time the entry and exit of light at the two ends of the optical fiber 6, thus promptly preventing the emission of the laser beam in the event of breakage or incorrect positioning of the optical fiber 6, thereby greatly increasing the active safety of the lighting assembly 4 and, consequently, of the entire lighting device 1.

[0128] In addition, the use of the ratio between the intensity of the light reflected / diffused outside the optical fiber at the proximal end 6a of the optical fiber 6 and the intensity of the light exiting from the distal end 6b of the optical fiber as a reference parameter for the automatic deactivation of the laser source 5 makes the lighting assembly 4 very reliable and safe.

[0129] In fact, experimental tests have shown that, in the laser sources currently on the market, the power of the emitted laser beam r varies significantly and suddenly depending on the production batch of the laser source 5, the aging of the laser source 5, the temperature reached by the emitter 13 of the laser source 5 and / or the intensity of the current currently circulating in the emitter 13 of the laser source 5.

[0130] The monitoring of the ratio between the intensity of the light reflected / diffused outside the optical fiber at the proximal end 6a of the optical fiber 6 and the intensity of the light exiting from the distal end 6b of the optical fiber eliminates the effects due to any variations / fluctuations in the power of the laser beam r emitted by the laser source 5.

[0131] In fact, these two quantities vary depending on the power of the laser beam r generated by the laser source 5.

[0132] Therefore, the deactivation of the laser source 5 is not affected by accidental fluctuations of the laser beam power due to the intensity of the current currently circulating in the emitter of the laser source, the temperature reached by the emitter of the laser source and / or the decay of the laser beam power due to the ageing of the laser source.

[0133] In addition, the deactivation of the laser source 5 is no longer affected by the performance differences of the laser sources 5 coming from different batches or manufacturers, thus greatly simplifying the manufacturing of the lighting device 1.

[0134] Finally, the combined use of the photometric sensors 8 and 9 can allow to understand, at the end of the production line of the lighting device 1 or along the same, whether the assembly of the lighting device 1, and more precisely of the lighting assembly 4, has been correctly carried out, bringing savings in this respect.

[0135] It is finally clear that modifications and variations can be made to the lighting device 1 and to the lighting assembly 4 described above, without departing from the scope of the present application.

[0136] For example, the laser source 5 of the lighting assembly 4 can be replaced by a high-power LED and by an optical collimator placed on the LED and suitable for collimating the light rays emitted by the LED into a collimated light beam (i.e. a set of collimated light rays having the same direction) directed towards the proximal end 6a of the radial emission optical fiber 6.

[0137] In other words, in a less complex implementation, the laser source 5 is replaced by a LED collimated light source.

[0138] In addition, the lighting device 1 can also be placed inside motor vehicles, for example for illuminating the entire or part of the passenger compartment of the vehicle.

[0139] In particular, with reference to Figure 6 and Figure 7 , the lighting device 1 can advantageously be placed / incorporated into a vehicle door 100 to illuminate the surrounding space.

[0140] In other words, the rear body 2 is suitable to be stably fixed to the vehicle inside the vehicle.

[0141] In particular, in the example shown, the lighting device 1 is preferably rectangular and is preferably sunk into the inner covering panel 101 of the vehicle door 100 so as to form a light band that illuminates the handrail area.

[0142] More in detail, in the example shown, the rear body 2 is preferably rectangular and is stably fixed or incorporated into the panel 101 of the vehicle door 100. On the other hand, the front half-shell 3 is preferably of a strip-like structure and is arranged so as to close the opening of the rear body 2, preferably substantially over the entire length of the rear body 2.

[0143] The optical fiber 6 preferably extends inside the rear body 2 substantially over the entire length thereof.

[0144] Preferably, the optical fiber 6 is also fixed on the ridge of the longitudinal rib 110, which preferably projects inside the rear body 2 substantially for the entire length of the rear body 2 or of the optical fiber 6.

[0145] In addition, the inner surface of the rear body 2 is preferably also mirror metallized so as to deflect the incident light towards the front half-shell 3.

[0146] In this embodiment, the proximal photodetector 8 and the distal photodetector 9 are arranged inside the rear body 2 at the two ends of the rear body 2, or in any case at the proximal portion 6a and at the distal portion 6b of the optical fiber 6.

[0147] In other words, in this embodiment, the lighting device 1 is preferably provided with a single lighting assembly 4 suitable for backlighting the entire front half-shell 3.

[0148] In addition, in this embodiment, the laser source 5 can also be located outside the rear body 2, preferably on the back of the panel 101, i.e. inside the vehicle door 100.

[0149] Obviously, the lighting device 1 can also be incorporated into a vehicle dashboard, for example for illuminating or backlighting the perimeter of the dashboard, or into the central console, for example for illuminating or backlighting the control panel located therein.

[0150] Finally, in different embodiments, the electronic control unit 7 can be programmed / configured to autonomously deactivate the laser source 5 when any one of the proximal photodetector 8 and the distal photodetector 9 detects an intensity of the laser that deviates from a corresponding predetermined reference value, to interrupt / stop the emission of the laser beam r.

[0151] Preferably, this reference value also varies as a function of the power / intensity of the laser beam r emitted by the laser source 5.

[0152] In other words, the electronic control unit 7 is programmed / configured to activate and deactivate the laser source 5 on the basis of an external command signal.

[0153] In addition, the electronic control unit 7 is preferably programmed / configured to automatically deactivate the laser source 5 when the intensity of the laser detected by the proximal photodetector 8 deviates from a first predetermined reference value and / or when the intensity of the laser detected by the distal photodetector 9 deviates from a second predetermined reference value.

[0154] In more detail, the electronic control unit 7 is preferably programmed / configured to automatically deactivate the laser source 5 when the intensity of the laser detected by the proximal photodetector 8 moves outside a predetermined first tolerance interval, which spans said first reference value and which is preferably also substantially centered on said first reference value.

[0155] Furthermore, the electronic control unit 7 is preferably programmed / configured to automatically deactivate the laser source 5 when the intensity of the laser light detected by the distal photometric sensor 9 moves outside a predetermined second tolerance interval, which spans over and is preferably also substantially centered on said second reference value.

[0156] In more detail, the electronic control unit 7 can be programmed / configured to automatically deactivate the laser source 5 when the intensity of the laser light detected by the proximal photometric sensor 8 deviates / varies by at least 3% with respect to said first reference value and / or when the intensity of the laser light detected by the distal photometric sensor 9 deviates / varies by at least 3% with respect to said second reference value.

Claims

1. An illumination device (1) for a vehicle, comprising: a rear body (2) suitable for being fixed to a vehicle; a front half-shell (3) arranged to close an opening of said rear body (2); and at least one lighting assembly (4) located inside said rear body (2) and suitable for backlighting a corresponding transparent or translucent portion of said front half-shell (3) according to instructions, said lighting assembly (4) comprising a radially emitting optical fiber (6) of given length and an electrically powered collimated light source (5) located in front of a proximal end (6a) of said optical fiber (6) and suitable for directing a collimated light beam (r) towards said proximal end (6a), which enters said optical fiber (6) and propagates inside it, characterized in that said lighting assembly (4) further comprises at least one proximal photometric sensor (8) arranged beside said collimated light source (5) and / or said proximal end (6a) of said optical fiber (6) to capture / detect light reflected / scattered when entering said optical fiber (6), at least one distal photometric sensor (9) arranged in front of a distal end (6b) of said optical fiber (6) and suitable for capturing / detecting light exiting from said distal end (6b) of said optical fiber (6), and an electronic control unit (7) suitable for controlling said collimated light source (5) on the basis of signals coming from said proximal photometric sensor (8) and said distal photometric sensor (9).

2. The illumination device of claim 1, wherein said electronic control unit (7) being suitable for deactivating said collimated light source (5) to interrupt / block the emission of said collimated light beam (r) when the ratio between the intensity of the light detected by at least one of said proximal photometric sensors (8) and the intensity of the light detected by at least one of said distal photometric sensors (9) deviates from a predetermined reference value.

3. The illumination device of claim 1, wherein said electronic control unit (7) being suitable for deactivating said collimated light source (5) to interrupt / block the emission of said collimated light beam (r) when the intensity of the light detected by either of said proximal photometric sensor (8) and said distal photometric sensor (9) deviates from a corresponding predetermined reference value.

4. The illumination device of claim 1, wherein said proximal end (6a) of said optical fiber (6) being arranged at a distance (d) of less than or equal to 0.5 mm from an emitter (13) of said collimated light source (5).

5. The illumination device of claim 1, wherein said lighting assembly (4) further comprising a centering and fixing mechanical member (11) suitable for rigidly connecting said proximal end (6a) of said optical fiber (6) to said collimated light source (5) and configured to stably keep said proximal end (6a) of said optical fiber (6) centered and fixed in front of said emitter (13) of said collimated light source (5).

6. The illumination device of claim 5, wherein, said centering and fixing mechanical member (11) being configured to stably keep said proximal end (6a) of said optical fiber (6) at a predetermined distance (d) ranging between 0.2 mm and 0.25 mm from said emitter of said collimated light source (5).

7. The illumination device of claim 1, wherein said lighting assembly (4) being provided with at least two of said proximal photometric sensors (8) arranged on opposite sides of an emitter (13) of said collimated light source (5).

8. The illumination device of claim 1, wherein, The emitter (13) of said collimated light source (5) and said proximal photodetector (8) are placed / fixed next to each other on a printed circuit board (15) arranged close to said proximal portion (6a) of said optical fiber (6).

9. The illumination device of claim 1, wherein, Said optical fiber (6) has a flexible filamentary structure and is supported / retained by a rigid load-bearing structure (10, 110) formed in one piece with said rear body (2).

10. The illumination device of claim 1, wherein, Said lighting assembly (4) is provided with at least one temperature sensor (12) suitable for detecting the temperature of said collimated light source (5).

11. The illumination device of claim 10, wherein, Said electronic control unit (7) is connected to said temperature sensor (12) and is suitable for amplifying the signals coming from at least one of said proximal photodetectors (8) and / or from at least one of said distal photodetectors (9) as a function of the temperature of said collimated light source (5).

12. The illumination device of claim 1, wherein, Said rear body (2) is substantially pot-shaped and is suitable for being at least partially sunk into the body of said vehicle.

13. The illumination device of claim 1, wherein, Said lighting device (1) is a headlight or a taillight of an automobile.

14. A control method of a lighting device (1) of an automobile, the lighting device having a lighting assembly (4) comprising: a radially emitting optical fiber (6) of given length; a collimated light source (5) arranged in front of a proximal portion (6a) of said optical fiber (6) and suitable for directing a collimated light beam (r) towards said proximal portion (6a), said collimated light beam entering said optical fiber (6) and propagating within said optical fiber (6); at least one proximal photodetector (8) arranged beside said collimated light source (5) and / or said proximal portion (6a) of said optical fiber (6) to capture / detect light reflected / diffused upon entering said optical fiber (6); and at least one distal photodetector (9) arranged in front of a distal portion (6b) of said optical fiber (6) and suitable for capturing / detecting light exiting from said distal portion (6b) of said optical fiber (6), characterized in that it comprises the steps of: - determining the intensity of light reflected / diffused outside said optical fiber (6) at said proximal portion (6a) of said optical fiber as a function of the signals coming from at least one of said proximal photodetectors (8); - determining the intensity of light exiting from said distal portion (6b) of said optical fiber (6) as a function of the signals coming from at least one of said distal photodetectors (9); and - switching off / deactivating said collimated light source (5) as a function of the intensity of light detected by at least one of said proximal photodetectors (8) and / or the intensity of light detected by at least one of said distal photodetectors (9).

15. The control method according to claim 14, characterized by, said collimated light source (5) is switched off / deactivated when the ratio between the intensity of light detected by at least one of said proximal photodetectors (8) and the intensity of light detected by at least one of said distal photodetectors (9) deviates from a predetermined reference value.

16. The control method according to claim 14, characterized by, It further comprises the steps of measuring the temperature of said collimated light source (5) and amplifying the signals coming from at least one of said proximal photodetectors (8) and / or from at least one of said distal photodetectors (9) as a function of the temperature of said collimated light source (5).

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