MOTOR VEHICLE LIGHT MODULE COMPRISING AN ELECTROCHROMIC DEVICE

Abstract

A light module of a motor vehicle lighting device. The light module includes a light source intended to perform at least one photometric function, and an electrochromic device including at least one portion arranged downstream of the light source and capable of optionally having a diffusing appearance or a transparent appearance. A controller is arranged to receive an emission instruction from the photometric function and to control, in accordance with the instruction, the emission of light by the light source and the appearance of the electrochromic device.

Claims

1. A light-emitting module for a motor-vehicle lighting device, comprising: a. a light source intended to participate in the performance of at least one photometric function; b. an electrochromic device comprising at least one segment arranged downstream of the light source and capable of selectively having a scattering aspect and a transparent aspect; and c. a controller arranged to receive an instruction to emit said photometric function and to control, depending on said instruction, the emission of light by the light source and the appearance of the electrochromic device.

2. The light-emitting module as claimed in claim 1, wherein the light source is intended to participate in the performance of at least a first photometric function and a second photometric function and wherein the controller is arranged to receive an instruction to emit either of the first and second photometric functions and to control, depending on said instruction, the emission of light by the light source and the appearance of the electrochromic device.

3. The light-emitting module as claimed in claim 2, wherein the first photometric function is a statutory daytime running light and wherein the second photometric function is a statutory road-lighting function, and wherein the controller is arranged to control the electrochromic device so that the electrochromic device has a scattering aspect on receipt of an instruction to emit the first photometric function and so that the electrochromic device has a transparent aspect on receipt of an instruction to emit the second photometric function.

4. The light-emitting module as claimed in claim 1, the light-emitting module comprising a projecting optical device arranged to receive light emitted by the light source and to project this light onto the road, wherein the electrochromic device is arranged downstream of the projecting optical device.

5. The light-emitting module as claimed in claim 1, the light-emitting module comprising a collecting optical device arranged to form light emitted by the light source into an intermediate light beam and a projecting optical device arranged to receive the intermediate light beam and to project it onto the road, wherein the electrochromic device is arranged between the collecting optical device and the projecting optical device.

6. The light-emitting module as claimed in claim 5, wherein the collecting optical device comprises a reflective surface configured to collect and reflect the light rays emitted by the light source, the projecting optical system being configured to project the light rays reflected by the reflective surface in a light beam along an optical axis (X-X) of the device, the light beam performing the first photometric function when the electrochromic device has a scattering aspect and the second photometric function when the electrochromic device has a transparent aspect.

7. The light-emitting module as claimed in claim 1, wherein the light source is a first light source and the segment of the electrochromic device is a first segment of the electrochromic device, characterized in that it comprises: d. a second light source, each of the first light source and second light source being intended to participate in the performance of a first photometric function and second photometric function, respectively; e. a projecting optical device configured to project the light rays emitted by the first light source and second light source in a first light beam and second light beam along an optical axis (X-X) of the device, respectively; f. a second segment arranged downstream of the second light source, the second segment being capable of selectively having a scattering aspect and a transparent aspect; and in that the controller is arranged to receive an instruction to emit either of the first and second photometric functions and to control, depending on said instruction, the emission of light by the first light source and/or second light source and the appearance of the first segment and/or second segment of said electrochromic device.

8. The light-emitting module as claimed in claim 7, wherein: a. the first light source and second light source, each of the first light source and second light source being intended to participate in the performance of a first photometric function and second photometric function, respectively; b. a projecting optical device configured to project the light rays emitted by the first light source and second light source in a first light beam and second light beam along an optical axis (X-X) of the device, respectively; c. an electrochromic device comprising a first segment arranged downstream of the first light source and a second segment arranged downstream of the second light source, each of the first and second segments being capable of selectively having a scattering aspect and a transparent aspect; and d. a controller arranged to receive an instruction to emit either of the first and second photometric functions and to control, depending on said instruction, the emission of light by the first light source and/or second light source and the appearance of the first segment and/or second segment of said electrochromic device.

9. The light-emitting module as claimed in claim 8, wherein the controller arranged to control, on receipt of an instruction to emit the first photometric function, the emission of light by the first light source, the first light beam performing the first photometric function.

10. The light-emitting module as claimed in claim 9, wherein the controller is arranged to control the electrochromic device so that the first segment has a transparent aspect and so that the second segment has a scattering aspect on receipt of an instruction to emit the first photometric function.

11. The light-emitting module as claimed in claim 7, wherein the controller is arranged to control, on receipt of an instruction to emit the second photometric function, simultaneous emission of light by the first light source and second light source, the first and second light beams together performing the second photometric function.

12. The light-emitting module as claimed in claim 11, wherein the controller is arranged to control the electrochromic device so that the first segment and second segment have a transparent aspect on receipt of an instruction to emit the second photometric function.

13. The light-emitting module as claimed in claim 7, wherein the first light source and second light source are respectively intended to participate together in the performance of a third photometric function, and wherein the controller is arranged to control, on receipt of an instruction to emit the third photometric function, simultaneous emission of light by the first light source and second light source, the first and second light beams together performing the second photometric function, and to control the electrochromic device so that the first segment and second segment have a scattering aspect.

14. The light-emitting module as claimed in claim 13, wherein the first photometric function is a statutory low-beam lighting function, the second photometric function is a statutory high-beam lighting function, and wherein the third photometric function is a statutory daytime-running-light signaling function.

15. The light-emitting module as claimed in claim 7, the light-emitting module comprising a first collecting optical device and a second collecting optical device, each collecting optical device being arranged to collect the light rays (LB, HB) emitted by the first and second light sources, respectively, the projecting optical device being arranged to receive the light rays collected by the collecting optical devices, the electrochromic device being arranged between the collecting optical devices and the projecting optical device.

16. The light-emitting module as claimed in claim 15, wherein the projecting optical device comprises a lens having a first entrance face for receiving the light rays emitted by the first light source and a second entrance face for receiving the light rays emitted by the second light source, the first segment of the electrochromic device being arranged facing the first entrance face and the second segment of the electrochromic device being arranged facing the second entrance face.

17. A lighting device for a motor vehicle, comprising a light-emitting module as claimed in claim 1.

18. The light-emitting module as claimed in claim 2, the light-emitting module comprising a projecting optical device arranged to receive light emitted by the light source and to project this light onto the road, wherein the electrochromic device is arranged downstream of the projecting optical device.

19. The light-emitting module as claimed in claim 2, the light-emitting module comprising a collecting optical device arranged to form light emitted by the light source into an intermediate light beam and a projecting optical device arranged to receive the intermediate light beam and to project it onto the road, wherein the electrochromic device is arranged between the collecting optical device and the projecting optical device.

20. The light-emitting module as claimed in claim 8, wherein the controller is arranged to control, on receipt of an instruction to emit the second photometric function, simultaneous emission of light by the first light source and second light source, the first and second light beams together performing the second photometric function.

Description

[0048] The present invention will now be described by way of examples that are merely illustrative and that in no way limit the scope of the invention, and with reference to the accompanying illustrations, in which:

[0049] FIG. 1 shows, partially and schematically, a light-emitting module according to one embodiment of the invention operating under night-time conditions;

[0050] FIG. 2 shows isolux curves of a light beam emitted by the light-emitting module of FIG. 1;

[0051] FIG. 3 shows, partially and schematically, the light-emitting module of FIG. 1 operating under daytime conditions; and

[0052] FIG. 4 shows isolux curves of a light beam emitted by the light-emitting module of FIG. 3;

[0053] FIG. 5 shows, partially and schematically, a light-emitting module according to one embodiment of the invention operating in a first operating mode;

[0054] FIG. 6 shows isolux curves of a light beam emitted by the light-emitting module of FIG. 5;

[0055] FIG. 7 shows, partially and schematically, the light-emitting module of FIG. 5 operating in a second operating mode;

[0056] FIG. 8 shows isolux curves of a light beam emitted by the light-emitting module of FIG. 7;

[0057] FIG. 9 shows, partially and schematically, the light-emitting module of FIG. 5 operating in a third operating mode; and

[0058] FIG. 10 shows isolux curves of a light beam emitted by the light-emitting module of FIG. 9.

[0059] In the following description, elements that are identical in terms of structure or in terms of function and that appear in various figures have been designated with the same reference, unless otherwise indicated. Furthermore, the terms “front”, “rear”, “top” and “bottom” must be interpreted in the context of the orientation of the lighting device such as it has been shown, corresponding to normal use of the lighting device, such as for example when mounted in a motor vehicle.

[0060] FIG. 1 shows a light-emitting module according to a first embodiment of the invention, when operating under night-time conditions.

[0061] The light-emitting module 1 comprises a light source 2, a collector 3 capable of reflecting the light rays emitted by the first light source in order to form a light beam 10 along an optical axis X-X of the module, and a lens 4 for projecting said beam. Projecting optical systems other than the projecting lens are envisionable, such as in particular one or more mirrors. If so desired, the light-emitting module will possibly comprise a second light source associated with another collector with a view to reflecting the light rays emitted by the second light source toward the lens 4 to form a second light beam along the optical axis X-X of the module.

[0062] The light source 2 is advantageously a semiconductor light source, such as in particular a light-emitting diode. This source 2 emits light rays in a half-space bounded by the main plane of said source 2, in the example shown in a main direction perpendicular to said plane and to the optical axis X-X.

[0063] The collector 3 comprises a carrier 5, of shell or skullcap shape, and a reflective surface 6 formed on the interior face of the carrier 5. The reflective surface 6 advantageously has an elliptical or parabolic profile. It is advantageously a surface of revolution about an axis parallel to the optical axis. Alternatively, it may be a question of a free-form surface or a swept surface or an asymmetric surface. It may also comprise a plurality of sectors. The shell- or skullcap-shaped collector 3 is advantageously made of materials that resist heat well, and for example of glass or of synthetic polymers such as polycarbonate PC or polyetherimide PEI. The expression “parabolic” generally applies to reflectors the surface of which has a single focus, i.e. one region of convergence of the light rays, i.e. one region such that the light rays emitted by a light source placed in this region of convergence are projected to a great distance after reflection from the surface. Projected to a great distance means that these light rays do not converge toward a region located at at least 10 times the dimensions of the reflector. In other words, the reflected rays do not converge toward a region of convergence or, if they do converge, this region of convergence is located at a distance larger than or equal to 10 times the dimensions of the reflector. A parabolic surface may therefore feature or not feature parabolic segments. A reflector having such a surface is generally used alone to create a light beam. Alternatively, it may be used as projecting surface associated with an elliptical reflector. In this case, the light source of the parabolic reflector is the region of convergence of the rays reflected by the elliptical reflector.

[0064] The light source 2 is placed at a focus of the corresponding reflective surface 6 so that the rays thereof are collected and reflected toward the lens 4.

[0065] The projecting lens 4 has an entrance face 41 for the light rays corresponding to the light beam 10, and an exit face 42 for this light beam 10. The lens 4 may have a focus 43 located on a region located between the reflective surface 6 of the collector 3 and the light source 2. In the present case, this focus 43 is on the reflective surface 6 of the collector 3. It will be noted that it is also possible for this focus to be located behind or in front of the reflective surface 6 provided that it is in proximity thereto, and preferably at less than 10 mm and preferably less than 5 mm therefrom.

[0066] The reflective surface, if it is elliptical, has a second focus located in front of the lens 4 and away from the optical axis X-X. It will be noted that it is also possible for this focus to be located behind the lens and/or on the optical axis, provided that it is in proximity to the lens, so as to decrease the width of the beam on the entrance face of the lens.

[0067] The light source 2 is mounted on a platen 7, a printed circuit board for example.

[0068] The light-emitting module 1 comprises a controller 8 capable of receiving an instruction to emit a given photometric function and arranged to control, depending on said instruction, activation of the light source 2 with a view to emitting the light beam 10. For this purpose, the controller 8 comprises a device for controlling the supply of electrical power to the light source 2, which is arranged to activate or deactivate this supply of electrical power or even to modify the value of the electrical power supplied to the light source 2.

[0069] The light-emitting module 1 comprises an electrochromic device 9 arranged downstream of the light source 2, between the collector 3 and the entrance face 41 of the lens 4. The electrochromic device 9 takes the form of a screen arranged on the whole in a plane passed through perpendicularly by the optical axis X-X, so that this screen is passed through by the light beam 10 after reflection from the reflective surface 6.

[0070] The electrochromic device 9 is formed by a stack of a plurality of layers including one or more layers of electrochromic material, tungsten trioxide for example, encapsulated between layers forming electrodes and layers forming transparent substrates. In a known manner, the opacity of the one or more layers of electrochromic material may be modified when electrical power is supplied to it or them. In this way, the electrochromic device may have a transparent aspect in which it lets light pass through it without substantially deflecting this light or a scattering aspect in which it scatters this light. According to the invention, the aspect of the electrochromic device 9 is controlled by the controller 8.

[0071] In the example shown, when the controller 8 receives an instruction to emit a lighting function, it controls the electrochromic device 9 so that the latter has a transparent aspect and it controls activation of the light source 2 so as to achieve the desired lighting function. For example, if the controller 8 receives an instruction to emit a low-beam lighting function, it controls activation of the light source 2 so that the light beam 10 is emitted and the electrochromic device 9 so that the latter has a transparent aspect.

[0072] FIG. 2 is a graphical representation of the images projected by the light-emitting module of FIG. 1 when the light source 2 is turned on and when the electrochromic device has a transparent aspect. The horizontal axis H and the vertical axis V cross on the optical axis of the light-emitting module. The curves shown are isolux curves, i.e. curves corresponding to regions of the light beam 10 that have the same luminance expressed in lux. The curves at the center correspond to a higher luminance level than on the periphery.

[0073] It may be seen that the light beam 10 has a top cutoff LB, essentially on the horizontal axis H. This top cutoff is a cutoff of the statutory low-beam type, produced by the rear edge 6.1 of the reflective surface 6 of the collector 3, as shown in FIG. 1. For this purpose, the focus 43 of the lens 4 is advantageously located in proximity to this edge 6.1, i.e. behind the light source 2. Advantageously, the light beam 10 reflected by the reflective surface 6 passes through the electrochromic device 9 before being projected by the lens 4. Due to the transparent aspect of the electrochromic device, the light beam 10 undergoes no substantial deflection on passing through this electrochromic device 9, and hence its photometric distribution, and in particular the top cutoff, is substantially not modified by this electrochromic device. In this way, the light beam 10 performs a photometric lighting function of the statutory low-beam type.

[0074] Advantageously, in order to compensate for optical losses caused by passage of the beam 10 through the electrochromic device 9, the controller 8 is arranged to control the electrical power supplied to the light source 2 to a value higher than the nominal value of this light source.

[0075] With reference to FIG. 3 and FIG. 4, the operation of the light-emitting module 1 under daytime conditions will now be described.

[0076] As shown in FIG. 3, when the controller 8 receives an instruction to emit a daytime signaling function, it controls the electrochromic device 9 so that the latter has a scattering aspect and it controls activation of the source 2 so as to achieve the desired signaling function. For example, if the controller 8 receives an instruction to emit a DRL function (DRL standing for daytime running light), it controls activation of the light source 2 so that the light beam 10 is emitted. It will be noted that the light beam 10 reflected by the reflective surface 6 of the collector 3 thus has a substantially identical photometric distribution under both daytime and night-time conditions.

[0077] Advantageously, the light beam 10 reflected by the reflective surface 6 of the collector 3 passes through the electrochromic device 9 and undergoes, due to the scattering aspect of the electrochromic device 9, a deflection that spreads its photometric distribution vertically and horizontally. This modified beam 11 is thus projected by the projecting lens 4 with a view to performing another photometric function.

[0078] FIG. 4 is a graphical representation of the images projected by the light-emitting module of FIG. 3 when only the light source 2 is turned on and when the electrochromic device 9 has a scattering aspect.

[0079] It may be seen that the light beam 11 projected by the lens 4 after scattering by the electrochromic device 9 is devoid of any top cutoff and is substantially more spread out than the low beam shown in FIG. 2. This photometric distribution is thus compatible with the regulatory requirements of the DRL function.

[0080] It will be noted that this distribution may be obtained through the controller 8 controlling the electrical power supplied to the light source 2 to a value substantially equal to the nominal value of this light source.

[0081] FIG. 5 shows a light-emitting module according to another embodiment of the invention, in a first operating mode.

[0082] The light-emitting module 1 comprises a first light source 2, a first collector 3 capable of reflecting the light rays emitted by the first light source in order to form a first light beam LB along an optical axis X-X of the module, and a lens 4 for projecting said beam. Projecting optical systems other than the projecting lens are envisionable, such as in particular one or more mirrors. The light-emitting module 1 further comprises a second light source 2′ that is opposite, with respect to the optical axis X-X, to the first light source 2 and a second collector 3′ that is also opposite to the first collector 3 and that is capable of reflecting the light rays emitted by the second light source 2′ so as to form a second light beam HB along the optical axis X-X of the module.

[0083] The light sources 2 and 2′ are advantageously semiconductor light sources, such as in particular light-emitting diodes. Each of the light sources 2 and 2′ emits light rays in a half-space bounded by the main plane of said source, in the shown example in a main direction perpendicular to said plane and to the optical axis X-X.

[0084] Each of the collectors 3 and 3′ comprises a carrier 5 and 5′, of shell or skullcap shape, and a reflective surface 6 and 6′ on the interior face of the carrier 5 and 5′. The reflective surfaces 6 and 6′ advantageously have an elliptical or parabolic profile. At least one thereof is advantageously a surface of revolution about an axis parallel to the optical axis. Alternatively, it may be a question of a free-form surface or a swept surface or an asymmetric surface. It may also comprise a plurality of sectors. The shell- or skullcap-shaped collectors 3 and 3′ are advantageously made from materials having a good heat resistance, for example of glass or of synthetic polymers such as polycarbonate PC or polyetherimide PEI. The expression “parabolic” generally applies to reflectors the surface of which has a single focus, i.e. one region of convergence of the light rays, i.e. one region such that the light rays emitted by a light source placed in this region of convergence are projected to a great distance after reflection from the surface. Projected to a great distance means that these light rays do not converge toward a region located at at least 10 times the dimensions of the reflector. In other words, the reflected rays do not converge toward a region of convergence or, if they do converge, this region of convergence is located at a distance larger than or equal to 10 times the dimensions of the reflector. A parabolic surface may therefore feature or not feature parabolic segments. A reflector having such a surface is generally used alone to create a light beam. Alternatively, it may be used as projecting surface associated with an elliptical reflector. In this case, the light source of the parabolic reflector is the region of convergence of the rays reflected by the elliptical reflector.

[0085] Each of the light sources 2 and 2′ is placed at a focus of the corresponding reflective surface 6 and 6′ so that the rays thereof are collected and reflected along the optical axis X-X.

[0086] The projecting lens 4 has a first entrance face 41 for the light rays corresponding to the first light beam LB, a second entrance face 41′ for the light rays corresponding to the second light beam HB, and an exit face 42 common to the two entrance faces. The lens 4 may have a first focus 43 and a second focus 43′, the first focus 43 corresponding to the top part of the lens 4 and the second focus 43′ corresponding to the bottom part of the lens 4. Each of the first and second foci 43 and 43′ in question is advantageously located in a region located between the reflective surface 6/6′ of the corresponding first or second collector 3/3′ and the corresponding first or second light source 2/2′ (these regions have been bounded by dashed lines). In the present case, at least one of the foci may be located on the reflective surface 6/6′ of the corresponding first or second collector 3/3′. It will be noted that it is also possible for this focus to be located behind or in front of the reflective surface 6/6′ provided that it is in proximity thereto, and preferably at less than 10 mm and preferably less than 5 mm therefrom.

[0087] The reflective surface, if it is elliptical, has a second focus located in front of the lens 4 and away from the optical axis X-X. It will be noted that it is also possible for this focus to be located behind the lens and/or on the optical axis, provided that it is in proximity to the lens, so as to decrease the width of the beam on the entrance face of the lens.

[0088] Still with reference to FIG. 1, it may be seen that the first light source 2 and the first collector 3, on the one hand, and the second light source 2′ and the second collector 3′, on the other hand, are opposite with respect to the optical axis X-X. In particular, the first light source 2 is placed on one face of a carrier 7 and the second light source 2′ is placed on an opposite face of the carrier 7. It is possible, for example, to place each light source on a platen, for example a printed circuit board, which is specific thereto, each platen being attached to the same heat sink. As a variant, the first and second light sources may be placed on opposite faces of a common platen.

[0089] The light-emitting module 1 comprises a controller 8 capable of receiving an instruction to emit a given photometric function and arranged to control, depending on said instruction, activation of the first light source 2 and/or second light source 2′ with a view to emitting the first light beam LB and/or second light beam HB. For this purpose, the controller 8 comprises a device for controlling the supply of electrical power to the light sources 2 and 2′ and is arranged to activate or deactivate this supply of electrical power or even to modify the value of the electrical power supplied to the light sources 2 and 2′.

[0090] The light-emitting module 1 comprises an electrochromic device 9 arranged downstream of the light sources 2 and 2′, between the collectors 3 and 3′ and the entrance faces 41 and 41′ of the lens 4. The electrochromic device 9 takes the form of a screen arranged on the whole in a plane passed through perpendicularly by the optical axis X-X, so that this screen is passed through by the light beams LB and HB before these beam penetrate into the lens 4. More precisely, the electrochromic device 9 comprises a first segment 91 and second segment 92, which are placed on either side of the optical axis X-X, so that the first segment 91 is substantially passed through by the light beam LB and so that the second segment 92 is substantially passed through by the light beam HB, though certain light rays emitted by one of the light sources 2 and 2′ may pass through the second segment 92 and first segment 91, respectively.

[0091] Each of the layers 91 and 92 of the electrochromic device 9 is formed by a stack of a plurality of layers including one or more layers of electrochromic material, tungsten trioxide for example, encapsulated between layers forming electrodes and layers forming transparent substrates. In a known manner, the opacity of the one or more layers of electrochromic material may be modified when electrical power is supplied to it or them. In this way, each layer 91 and 92 of the electrochromic device may have a transparent aspect in which it lets light pass through it without substantially deflecting this light or a scattering aspect in which it scatters this light. According to the invention, the aspect of each of the layers 91 and 92 of the electrochromic device 9 is controlled independently by the controller 8, depending on the received emit instruction.

[0092] In the operating mode shown in FIG. 5, the controller 8 receives an instruction to emit a low-beam lighting function. In response, it controls the first layer 91 of the electrochromic device 9 so that it has a transparent aspect and the second layer 92 so that it has a scattering aspect. The controller also controls activation of the first source 2 by supplying thereto an electrical power of value substantially identical to its nominal value, and activation of the second source 2′ by supplying thereto an electrical power of value substantially lower than its nominal value.

[0093] FIG. 6 is a graphical representation of the images projected by the light-emitting module 1 in the operating mode of FIG. 5. The horizontal axis H and the vertical axis V cross on the optical axis of the light-emitting module. The curves shown are isolux curves, i.e. curves corresponding to regions of the light beam projected by the lens 4 that have the same luminance expressed in lux. The curves at the center correspond to a higher luminance level than on the periphery.

[0094] It may be seen that the first light beam LB has a top cutoff, essentially on the horizontal axis H. This top cutoff is a cutoff of the statutory low-beam type, produced by the rear edge 6.1 of the reflective surface 6 of the first collector 3, as shown in FIG. 5. For this purpose, the first focus 43 of the lens 4 is advantageously located in proximity to this edge 6.1, i.e. behind the first light source 2. Advantageously, the first light beam LB passes through the segment 92 of the electrochromic device 9 without being substantially deflected in any way, then penetrates into the lens 4 via the entrance face 41 and is projected onto the road. It may thus be seen that its photometric distribution, and in particular the top cutoff, is substantially not modified by this electrochromic device, and thus allows a first photometric function, namely a low-beam lighting function, to be performed.

[0095] Moreover, stray rays from the first light beam LB that reach the second segment 92 are scattered by this second segment, and hence even if some of these rays are projected by the lens 4 above the top cutoff, their brightness is decreased by this scattering and hence no discomfort glare is caused thereby.

[0096] Furthermore, the second light beam HB emitted by the second light source 2′ and reflected by the second collector 3′ has a low brightness given the low value of the electrical power received by the second light source 2′. This second light beam is intercepted by the second segment 92 and is also spatially spread, due to the scattering aspect of this second segment. Therefore, the light beam HB penetrates into the lens 4 via the entrance face 41′ and is projected above the top cutoff of the beam LB, but with a brightness such that it does not cause discomfort glare, and hence the overall beam projected by the lens complies with the regulatory requirements for the low-beam lighting function. As such, neither the stray rays nor the light beam HB have been shown in FIG. 6. Lastly, it will be noted that the exit face 42 of the lens 4 is wholly illuminated by the beams LB and HB.

[0097] FIG. 7 shows a second operating mode of the light-emitting module 1 of FIG. 5, in which the controller 8 receives an instruction to emit a high-beam lighting function. In response to this instruction, it controls the first layer 91 of the electrochromic device 9 so that it has a transparent aspect and the second layer 92 so that it also has a transparent aspect. The controller also controls activation of the first source 2 by supplying thereto an electrical power of value substantially identical to its nominal value, and activation of the second source 2′ by supplying thereto an electrical power of value substantially identical to its nominal value.

[0098] FIG. 8 is a graphical representation of the images projected by the light-emitting module 1 in the operating mode of FIG. 7.

[0099] The second light beam HB extends substantially above the top cutoff of the beam LB, so as to complement this first light beam LB. This concentration of light above the top cutoff is achieved via the portion of the reflective surface 6′ that is in proximity to the rear edge 6.1′. For this purpose, the second focus 43′ of the lens 4 may be located in proximity to the rear edge 6.1′. Each light beam LB and HB thus passes through the first layer 91 and second layer 92 of the electrochromic device 9, respectively, without undergoing any substantial deviation, and thus penetrates the lens 4, via the entrance faces 41 and 41′, respectively, so as to be projected onto the road. The combination of the first and second light beams LB and HB together thus forms a beam that complies with the regulatory requirements for the high-beam lighting function. The light-emitting module 1 thus performs a second photometric function, namely a high-beam lighting function. It will moreover be noted that the exit face 42 of the lens 4 is wholly illuminated by the beams LB and HB.

[0100] FIG. 9 shows a third operating mode of the light-emitting module 1 of FIG. 5, in which the controller 8 receives an instruction to emit a DRL signaling function. In response to this instruction, it controls the first layer 91 of the electrochromic device 9 so that it has a scattering aspect and the second layer 92 so that it also has a scattering aspect. The controller also controls activation of the first source 2 by supplying thereto an electrical power of value substantially identical to its nominal value, and activation of the second source 2′ by supplying thereto an electrical power of value substantially identical to its nominal value.

[0101] Under these conditions, it will be noted that the light beams LB and HB, reflected by the reflective surfaces 6 and 6′, each have, before passing through the segments 91 and 92 of the electrochromic device 9, a photometric distribution substantially identical to those of FIG. 8.

[0102] Advantageously, each of the first and second light beams LB and HB passes through segments 91 and 92 of the electrochromic device 9, respectively, and undergoes, due to the scattering aspect of this segment, a deflection that spreads its photometric distribution vertically and horizontally, then penetrates into the lens 4 via the entrance faces 41 and 41′, respectively, so as to be projected. Together the two projected beams thus form a DRL beam.

[0103] FIG. 10 is a graphical representation of the images projected by the light-emitting module 1 in the operating mode of FIG. 9.

[0104] It may be seen that the DRL light beam projected by the lens 4 is devoid of any top cutoff and is far more spread out than the low beam shown in FIG. 6 or the high beam shown in FIG. 8. This photometric distribution is thus compatible with the regulatory requirements of the DRL function. The light-emitting module 1 thus performs a third photometric function, namely a DRL function. It will be noted that, in this third operating mode, the exit face 42 of the lens 4 is wholly illuminated by the beams LB and HB.

[0105] It will thus be understood that, by virtue of the invention and in particular by virtue of the use of an electrochromic device the aspect of which is controlled depending on the desired photometric function, the light-emitting module has a luminous signature, i.e. an appearance when turned on, that remains constant, both day and night, while allowing daytime and night-time photometric functions to be performed in accordance with the regulatory requirements for these functions. Likewise, by virtue of the invention and in particular by virtue of the use of an electrochromic device with two layers the aspect of which is controlled independently depending on the desired photometric function, the light-emitting module has a luminous signature, i.e. an appearance when turned on, that remains constant, both day and night, while allowing lighting and signaling photometric functions to be performed and while remaining compact overall.

[0106] In any event, the invention should not be regarded as being limited to the embodiments specifically described in this document, and extends, in particular, to any equivalent means and to any technically operative combination of these means. In particular, it is possible to envision arranging the electrochromic device in a different way to the one described—for example, it might be placed downstream of the projection lens. It is also possible to envision using the described light-emitting module for daytime and night-time functions other than those described, for example for segmented or pixelated low-beam or high-beam lighting functions. It is also possible to envision using the described light-emitting module for day-time and night-time functions other than those described, for example for segmented or pixelated low-beam or high-beam lighting functions and for direction-indicator-light or position-light signaling functions. Moreover, it is possible to envision integrating an electrochromic device into a light-emitting module having an optical structure different from that described, and in particular into a light-emitting module comprising a matrix array of light sources each associated with one primary optic, for example a collimator or microlens, the assembly formed therefrom being combined with a projecting optical system, for example one formed by a succession of projecting field lenses.