EP4111093A1

EP4111093A1 - Motor vehicle light module comprising an electrochromic device

Info

Publication number: EP4111093A1
Application number: EP21703294.5A
Authority: EP
Inventors: Matthieu SYRE; Stephane WINTERSTEIN; Blaise Jars; Gavin Warner; Sylvain Giraud
Original assignee: Valeo Vision SAS
Current assignee: Valeo Vision SAS
Priority date: 2020-02-27
Filing date: 2021-02-10
Publication date: 2023-01-04
Also published as: WO2021170400A1; US20230070403A1; CN115151755A; US11841122B2

Abstract

The invention relates to a light module (1) of a motor vehicle lighting device, comprising: a light source (2, 2') intended to perform at least one photometric function, an electrochromic device (9) comprising at least one portion (91, 92) arranged downstream of the light source (2, 2') and capable of optionally having a diffusing appearance or a transparent appearance, and a controller (8) 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 (2, 2') and the appearance of the electrochromic device (9).

Description

Title of the invention: Motor vehicle light module comprising an electrochromic device

The invention relates to the field of automotive lighting. More specifically, the invention relates to the field of lighting devices for motor vehicles incorporating light modules having a constant light signature day and night and / or capable of performing several photometric functions.

The lighting devices of motor vehicles, and in particular the front headlamps, strongly participate in the aesthetic appearance of these vehicles. In particular, car manufacturers now design the style of these lighting devices so that their luminous appearance makes it possible to differentiate them from other manufacturers thanks to a unique light signature produced by the various lighting and signaling modules. when they are on, day or night.

Against this need for a single light signature are regulatory constraints defining not only the photometry of the light beams, whether for signaling or lighting, but also the period, night or day, during which these light beams must be emitted. This is how we distinguish, for example, the signaling function of the daytime running light type, also called DRL for the English Daytime Running Light, which must be on during the day, and the lighting functions of the road or crossing type which must be lit at night. These functions have different photometric distributions and cannot be activated simultaneously.

However, it is necessary to pool as much as possible these different functions within a single light module, so as to reduce the cost and size of the lighting devices.

[0005] It is also known practice to incorporate into lighting devices light modules comprising several selectively controllable light sources and thus making it possible to perform several photometric functions, such as, for example, lighting functions of the road or crossing type.

[0006] Usually, this type of light module employs an optical projection device, for example a lens or a reflector, making it possible to project on the road the light beams suitable for performing these functions. For example, a first light source emits light rays to perform only a lighting function of the crossing type and a second light source emits light rays to perform, with the light rays emitted by the first light source, a lighting function. road type.

[0007] These photometric functions are framed by defined regulatory constraints in particular the photometry of the light beams which produce them, that is to say the spatial light distribution of these light beams. In particular, for the function crossing type lighting, the regulations require the delimitation of the light beam by an upper cut-off, for example horizontal, above which no dazzling light is authorized.

In order to form this upper cutoff, it is known to add to the light module a cover intended to intercept part of the light rays emitted by the first light source and whose front edge has a profile conforming to this cutoff, the device projection having a focus disposed at this front edge. However, this cover must be positioned very precisely, so that the focal point of the optical projection device is correctly positioned at the level of the front edge. In addition, the cover weighs down the light module and increases its size.

[0009] As a variant, in order to simplify the production of the light module and to reduce its size, it is known to associate each light source with a reflector type collector, a rear edge of which forms said cut-off, part of the device projection optics specific to this light source being focused in this case at the level of the rear edge of the associated collector. However, this type of light module generally requires an opaque screen arranged horizontally in the module so as to prevent parasitic rays emitted by the first light source from being projected by the part of the projection optical device specific to the second light source above. of the upper cutoff. This opaque screen increases the size of the light module.

Finally, we see that the lit appearance of these types of modules vary depending on the photometric function that is performed. In fact, in the case of a projection lens, only part of the lens is illuminated when performing a lighting function of the crossing type while the whole of the lens is illuminated when performing a lighting function. road type lighting. In addition, these modules do not make it possible to perform signaling functions, in particular daytime functions. Therefore, it is not possible to obtain with these types of module a unique light signature, in particular day and night.

[0011] There is thus a need for a light module of a motor vehicle lighting device having a single light signature, generally constant day and night, capable of participating in the realization of different distinct photometric functions and of which the horizontal encumbrance is contained.

The present invention falls within this context and aims to meet this need.

For these purposes, the invention relates to a light module of a lighting device of a motor vehicle, comprising a light source intended to participate in the realization of at least one photometric function, a device electrochromic comprising at least one portion arranged downstream of the light source and capable of selectively exhibiting a diffusing appearance and a transparent appearance; and a controller arranged to receive an instruction to transmit said photometric function and to control, as a function of said instruction, the emission of light by the light source and the appearance of the device. electrochromic.

Advantageously, the light source is intended to participate in the realization of at least a first photometric function and a second photometric function and in which the controller is arranged to receive an emission instruction from one or the other first and second photometric functions and for controlling, as a function of said instruction, the emission of light by the light source and the appearance of the electrochromic device.

According to the invention, the electrochromic device, when it is transparent, is capable of letting through the light emitted by the light source without substantially deviating it to participate in the performance of all or part of one of the functions photometric. Moreover, when it is diffusing, the electrochromic device is capable of deflecting this light to obtain another photometric distribution and thus participate in the realization of all or part of the other of the photometric functions. Thus, the module according to the invention is capable of performing different photometric functions via the same output face of the light module, so that it is, however, possible to obtain a light signature that is generally constant, for example during daylight hours. by night.

Electrochromic device is understood to mean a device comprising a layer of electrochromic material, the optical properties of which, and in particular its opacity, change when a voltage or an electric current is applied to it. For example, said layer of electrochromic material can be encapsulated between different layers, in particular layers forming electrodes and layers forming substrates. It should be noted that the diffusing or transparent aspect of the electrochromic device persists in the absence of an electrical supply. If desired, the electrochromic device can be a flexible screen or film. For example, the controller is arranged to control an electrical power supply supplied to the electrochromic device, and in particular to the layers forming the electrodes of this electrochromic device, in order to control its appearance. According to one example, the electrochromic device may have the diffusing appearance in the absence of electric voltage at the terminals of these layers forming the electrodes and the transparent appearance when an electric voltage is present at the terminals of these layers forming the electrodes.

By electrochromic device arranged downstream of the light source is meant an electrochromic positive device arranged on the optical path of the light emitted by this light source, directly or after deflection by an optical device, towards the outside of the light module, so that all or part of this light passes through it. Preferably, the electrochromic device extends generally along a plane traversed, in particular substantially perpendicularly, by an optical axis of the light module.

In one embodiment of the invention, the first photometric function is a regulatory daytime running light and the second photometric function is a regulatory road lighting function, in particular a regulatory crossing type lighting, a regulatory road type lighting or even segmented or pixelated road type lighting. Where appropriate, the controller is arranged to control the electrochromic device so that the electrochromic device exhibits a diffusing appearance when receiving an instruction to transmit the first photometric function and so that the electrochromic device exhibits a diffusing appearance. transparent appearance when receiving an instruction to send the second photometric function. In other words, when receiving an instruction to transmit the second photometric function, the electrochromic device has substantially no impact on the photometric distribution of the light beam produced by means of the light emitted by the light beam. The source. It is thus possible to freely associate an optical device with this light source in order to obtain a photometric distribution in accordance with the regulatory requirements of the second photometric function. On the other hand, when receiving an instruction to send the first photometric function, the electrochromic device, thanks to its diffusing appearance, spreads this light beam to obtain a photometric distribution compatible with the regulatory requirements of the function. daytime running light.

Advantageously, the controller is arranged to control a power supply supplied to the light source and the controller is arranged to control the power supply supplied to the light source at its nominal value upon receipt of an instruction. emission of the first photometric function.

If necessary, the controller can be arranged to control the power supply supplied to the light source at a value greater than or equal to its nominal value when receiving an instruction to send the second photometric function . In the case of a value equal to the nominal value, the control of the electrical supply is simplified. In the case of a value greater than the nominal value, the loss of efficiency caused by the optical losses due to the passage of light through the electrochromic device is compensated for.

In one embodiment of the invention, the light module comprises an optical projection device arranged to receive the light emitted by the light source and to project this light on the road and the electrochromic device is arranged downstream of the optical projection device. By projection device is meant, for example, a device comprising one or more lenses and / or one or more reflectors, arranged to receive the light emitted, directly or indirectly, by the light source and defining a light output face of the light module. . If desired, the electrochromic positive device can be arranged between the optical projection device and a closing glass of a motor vehicle lighting device incorporating the light module according to the invention.

In another embodiment of the invention, the light module comprises a collection optical device arranged to collect the light emitted by the light source in an intermediate light beam and an optical projection device arranged for receiving the intermediate light beam and projecting it onto the road, in which the electrochromic device is arranged between the collection optical device and the projection optical device. For example, the collection optical device may comprise one or a combination of several of the following elements: reflector, lens, collimator, light guide, this or these elements being arranged to collect the light emitted by the light source.

Advantageously, the collection optical device can include a healthy reflecting surface configured to collect and reflect the light rays emitted by the light source and the projection optical system can be configured to project the light rays reflected by the reflecting surface in a light beam along an optical axis of the light module. Where appropriate, the light beam performs the first photometric function when the electrochromic device has a diffusing appearance and the second photometric function when the electrochromic device has a transparent appearance.

[0024] For example, the projection optical device can be configured to form a light image of the reflecting surface of the collection optical device so that the light beam has a higher horizontal cutoff. Advantageously, said upper horizontal cut-off is formed by the rear edge of the reflecting surface of the optical projection device, the optical projection device having a focal point arranged in the vicinity of this rear edge. If desired, said upper horizontal cutoff may be a regulatory crossing type cutoff. Alternatively, the projection optical device may be configured to form an image of the reflective surface of the collection optical device such that the light beam has a lower horizontal cutoff. According to another variant, the projection optical device can be configured to form an image of the reflecting surface of the collection optical device so that the light beam has the shape of a light segment.

In another embodiment of the invention, the light source is a first light source, the portion of the electrochromic device is a first portion of the electrochromic device, characterized in that it comprises a second light source, each first and second light sources being intended to participate in the production, respectively, of a first and a second photometric function; a projection optical device configured to project the light rays emitted by the first and second light sources, respectively, into a first light beam and a second light beam along an optical axis of the device; a second portion arranged downstream of the second light source, the second portion being able to selectively present a diffusing appearance and a transparent appearance; and in that the controller is arranged to receive an instruction to transmit one or the other of the first and second photometric functions and to control, as a function of the- said instruction, the emission of light by the first light source and / or by the second light source and the appearance of the first and / or of the second portion of said electrochromic positive device.

According to the invention, each portion of the electrochromic device, when it is transparent, is capable of letting through the light emitted by the light source with which it is associated without substantially deviating it, thus participating in the achievement of the first or second photometric. Moreover, when it is diffusing, the electrochromic device is capable of deflecting this light. It is thus possible on the one hand to modify the photometric distribution of the first and / or of the second light beam to obtain distributions compatible with light signaling functions. In addition, it is possible to intercept or diffuse parasitic rays emitted by one of the light sources towards the portion of the electrochromic device associated with the other of the light sources, which would be liable to be dazzling and therefore contrary to the requirements. regulatory. Furthermore, in the event that only one of the light sources needs to be activated for performing a photometric function, it is possible to activate the other light source so as to obtain an illuminated appearance of the light module similar to that of the light module. case where both light sources must be activated. Thus, the module according to the invention is capable of performing several photometric, lighting and signaling functions and it makes it possible to obtain a generally constant light signature, day and night. Finally, the horizontal size of the electrochromic device being less than that of a cover or an opaque screen, the total size of the light module is reduced.

Electrochromic device is understood to mean a device comprising a layer of electrochromic material, the optical properties of which, and in particular its opacity, change when a voltage or an electric current is applied to it. For example, said layer of electrochromic material can be encapsulated between different layers, in particular layers forming electrodes and layers forming substrates. It should be noted that the diffusing or transparent aspect of the electrochromic device persists in the absence of an electrical supply. If desired, the electrochromic device can be a flexible screen or film. Advantageously, the layer of electrochromic material may be common to the two portions of the electrochromic device, and each portion may include layers forming electrodes which are specific to it, so that each portion can be controlled independently of the other. As a variant, each portion of the electrochromic device may comprise a layer of electrochromic material and layers forming electrodes which are specific to it, all of these layers of the two portions being encapsulated between the same common layers forming substrates. For example, the controller is arranged to control an electrical power supply supplied to each portion of the electrochromic device, and in particular to the layers forming the electrodes of each portion of this electrochromic device, in order to control its appearance. According to a example, each portion of the electrochromic device may have the diffusing appearance in the absence of electric voltage at the terminals of the layers forming the electrodes of this portion and the transparent appearance when an electric voltage is present at the terminals of these layers forming the electrodes .

The term “portion of an electrochromic device arranged downstream of a mining source is understood to mean a portion of an electrochromic device arranged on the optical path of the light emitted by this light source, directly or after deflection by an optical device , towards the outside of the light module, so that all or part of this light passes through it. Preferably, the electrochromic device extends generally along a plane traversed, in particular substantially perpendicularly, by an optical axis of the light module.

The controller may include a device for controlling the electrical power supplied to each of the first and second light sources, the control device being able to activate or deactivate this electrical supply or even to modify the value of the electrical power supplied. to each of the light sources.

In one embodiment of the invention, the controller is arranged to control, on receipt of an instruction to transmit the first photometric function, the emission of light by the first light source, the first beam light performing the first photometric function. In other words, the first light source is designed to perform the first photometric function on its own. It could for example be a lighting function of the regulatory crossing type; or a complementary road-type lighting function intended to supplement a crossing-type function to together form a regulatory road-type function; or a light segment or pixel of a lighting function of the crossing or road segmented or pixelated type.

[0031] For example, the controller can be arranged to control the emission of light only by the first light source when receiving an instruction to send the first photometric function. As a variant, the controller can be arranged to control the emission of light simultaneously by the first light source and by the second light source when receiving an instruction to transmit the first photometric function. Where appropriate, the controller may be arranged to control the electrical power supplied to the first light source at a value greater than or equal to its nominal value and to control the electrical power supplied to the second light source at a value less than. its face value. In this way, the first light source emits enough light for the light module to perform the first photometric function while the quantity of light emitted by the second light source is insufficient to be dazzling but is sufficient for the entire device. projection optics receive light from both light sources and the light module has a generally illuminated appearance. Advantageously, the controller is arranged to control the electrochromic device so that the first portion has a transparent appearance and so that the second portion has a diffusing appearance when receiving a transmission instruction from the first photometric function. It is thus understood that the first portion of the electrochromic positive device has substantially no impact on the photometric distribution of the first light beam produced by means of the light emitted by the first light source. In addition, the diffusing aspect of the second portion intercepts and diffuses the light rays emitted by the first source towards this second portion, so as to avoid projecting dazzling light. Finally, in the case where the second source lu miner also emits light, the second portion also diffuses this light to prevent it from being dazzling.

In another alternative or cumulative embodiment, the controller is arranged to control, on receipt of an instruction to transmit the second photometric function, the simultaneous emission of light by the first light source and by the second light source, the first and second light beams together performing the second photometric function. In other words, the first light source and the second light source are intended to together perform the second photometric function. It could for example be a lighting function of the regulatory road type. Where appropriate, the controller may be arranged to control the power supply supplied to the first light source at a value greater than or equal to its nominal value and to control the power supply supplied to the second light source at a higher value. or equal to its face value.

Advantageously, the controller is arranged to control the electrochromic device so that the first portion and the second portion have a transparent appearance when receiving an instruction to send the second photometric function. It is thus understood that each portion of the electrochromic device has substantially no impact on the photometric distribution of the first or of the second light beam produced by means of the light emitted by the first or the second light source.

In another alternative or cumulative embodiment, the first light source and the second light source are intended to participate together in the realization, respectively, of a third photometric function. Where appropriate, the controller is arranged to control, on receipt of an instruction to transmit the third photometric function, the simultaneous emission of light by the first light source and by the second light source, the first and second beams. luminous apparently performing the second photometric function. The controller further controls the electrochromic device so that the first portion and the second portion exhibit a diffusing appearance. Where appropriate, the controller can be arranged to control the electrical power supplied to the first light source at a value greater than or equal to its nominal value and to control the power supplied to the second light source at a value greater than or equal to its nominal value. In this way, each portion of the electrochromic device, thanks to its diffusing aspect, spreads the first and second light beams to obtain an overall photometric distribution compatible with the regulatory requirements of a light signaling function.

For example, the first photometric function may be a lighting function of regulatory crossing type, the second photometric function may be a lighting function of regulatory road type and the third photometric function may be a signaling function of regulatory daytime running light type. We thus obtain a globally constant light signature, day and night.

According to an exemplary embodiment of the invention, the light module comprises a first optical collection device, or first collector, and a second optical collection device, or second collector, each optical collection device being arranged to collect the light rays emitted, respectively, by the first and the second light source; the optical projection device being arranged to receive the light rays collected by the collection optical devices. Where appropriate, the electrochromic device is arranged between the collection optical devices and the optical projection device, for example in the vicinity of the optical projection device.

By projection device is meant for example a device comprising one or more lenses and / or one or more reflectors, arranged to receive the light emitted, directly or indirectly, by the light sources and defining an output face of light from the light module. Likewise, the collection optical device may comprise one or a combination of several of the following elements: reflector, lens, collimator, light guide, this or these elements being arranged to collect the light emitted by the corresponding light source.

Advantageously, each collection optical device comprises a health reflecting surface configured to collect and reflect the light rays emitted, respectively, by the first and the second light source. Where appropriate, the optical projection device is configured to form a luminous image of the reflective surface of each of the collection optical devices.

Advantageously, the first collector and the first light source are arranged relative to the second collector and to the second light source so that the light image of the reflecting surface of the first collector is inverted, with respect to the optical axis, to the luminous image of the reflecting surface of the second collector. For example, the first collector and the first light source are opposite, with respect to the optical axis, the second collector and the second light source.

Advantageously, the reflecting surfaces of the first and second collectors present an elliptical or parabolic profile. Preferably, it is a surface of revolution of said profile. The revolution is around an axis advantageously parallel to the optical axis. According to one variant, the reflecting surface is a free-form surface (in English “free form”) or a swept surface or an asymmetric surface. It can also include several sectors. For example, the reflecting surface of each of the first and second collectors is concave and has, with respect to a general direction of propagation of the corresponding light beam, a front edge and a rear edge, said edges defining in opposite directions the light image corresponding.

Advantageously, the optical projection device has a first focal point located axially behind a front limit of the reflecting surface of the first collector, and / or a second focal point located axially behind a front limit of the reflective surface of the second collector. For example, the first focal point could be located at a rear edge of the reflecting surface of the first collector and the second focal point could be located at a rear edge of the reflecting surface of the second reader neck.

According to an advantageous embodiment of the invention, the first and the second light source are arranged on a common plate.

Advantageously, the optical projection device comprises a lens comprising a first input face for receiving the light rays emitted by the first light source and a second input face for receiving the light rays emitted by the second light source, the first portion of the electrochromic device being arranged facing the first input face and the second portion of the electrochromic device being arranged facing the second input face. For example, each portion is arranged in the vicinity of an entrance face of the lens. Where appropriate, the lens has an outlet face common to the first and second inlet faces.

For example, the electrochromic device can be in one piece, the first and the second portion being separated by a border. Where appropriate, the first and second entry faces of the lens may be contiguous at the level of a junction zone, said border being aligned with the junction zone, and in particular with the optical axis.

If desired, the first and second input faces are aligned perpendicular to the optical axis.

A subject of the invention is also a lighting device for a motor vehicle, comprising a light module according to the invention. The lighting device could for example be arranged as a headlight of a motor vehicle.

The present invention is now described with the aid of examples which are only illustrative and in no way limitative of the scope of the invention, and from the accompanying illustrations, in which:

[0049] [Fig. 1] shows, partially and schematically, a light module according to an embodiment of the invention operating in night conditions;

[0050] [Fig. 2] represents isoluxes of a light beam emitted by the light module of [Fig. i]; [0051] [Fig. B] represents, partially and schematically, the light module of [Fig. 1] operating under daytime conditions; and

[0052] [Fig.4] represents isolux of a light beam emitted by the light module of [Fig.

3]

[0053] [Fig. 5] shows, partially and schematically, a light module according to an embodiment of the invention operating in a first mode of operation;

[0054] [Fig. 6] represents isoluxes of a light beam emitted by the light module of [Fig.

5];

[0055] [Fig. 7] represents, partially and schematically, the light module of [Fig. 5] operating in a second mode of operation;

[0056] [Fig. 8] represents isoluxes of a light beam emitted by the light module of [Fig.

7];

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

[0058] [Fig. 10] represents isoluxes of a light beam emitted by the light module of [Fig. 9]

In the following description, the identical elements, by structure or by function, appearing in different figures retain, unless otherwise specified, the same references. In addition, the terms "front", "rear", "top" and "bottom" should be interpreted in the context of the orientation of the lighting device as shown, corresponding to normal use of the light. lighting device, such as for example when it is mounted in a motor vehicle.

There is shown in [Fig. 1] a light module according to a first embodiment of the invention, when it operates in night conditions.

The light module 1 comprises a light source 2, a collector 3 capable of reflecting the light rays emitted by the first light source to form a light beam 10 along an optical axis XX of the module, and a projection lens 4 of said beam. Other optical projection systems than the projection lens can be envisaged, such as in particular one or more mirrors. If desired, the light module could include a second light source associated with another collector to reflect the light rays emitted by the second light source towards the lens 4 to form a second light beam along the optical axis X-X of the module.

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

The collector 3 comprises a support 5, in the form of a shell or cap, and a reflecting surface 6 formed on the inner face of the support 5. The reflecting surface 6 advantageously has a profile of the elliptical or parabolic type. It is advantageously a surface of revolution about an axis parallel to the optical axis. Alternatively, it may be a free-form surface or a swept surface or an asymmetric surface. It can also include several sectors. The collector 3 in the form of a shell or cap is advantageously made of materials having good heat resistance, for example glass or synthetic polymers such as polycarbonate PC or polyetherimide PEI. The expression “parabolic type” applies generally to reflectors the surface of which has a single focal point, that is to say a zone of convergence of light rays such as the light rays emitted by a light source placed at the center. level of this convergence zone are projected at a great distance after reflection on the surface. Projected at a great distance means that these light rays do not converge on an area that is at least 10 times the dimensions of the reflector. In other words, the reflected rays do not converge towards a convergence zone or, if they converge, this convergence zone is situated at a distance greater than or equal to 10 times the dimensions of the reflector. A parabolic type surface may or may not have parabolic portions. A reflector having such a surface is generally used alone to create a light beam. Alternatively, it can be used as a projection surface associated with an elliptical type reflector. In this case, the light source of the parabolic type reflector is the zone of convergence of the rays reflected by the elliptical type reflector.

The light source 2 is arranged at a focal point of the corresponding reflecting surface 6 so that its rays are collected and reflected towards the lens 4.

The projection lens 4 has an input face 41 of the light rays corresponding to the light beam 10 and an output face 42 of this light beam 10. The lens 4 can have a focus 43 located on an area between the reflecting surface 6 of the collector 3 and the light source 2. In this case, this focus 43 is on the reflective surface 6 of the collector 3. It should be noted that it is also possible that this focus is located at the behind or in front of the reflecting surface 6 as long as it is close to, preferably less than 10 mm, preferably less than 5 mm.

The reflecting surface, if it is of the elliptical type, has a second focal point located at the front of the lens 4 and at a distance from the optical axis X-X. It should be noted that it is also possible for this focus to be located at the rear of the lens and / or on the optical axis, as long as it is close to the lens, so as to reduce the width of the beam. at the entry face of the lens.

The light source 2 is mounted on a plate 7, for example a printed circuit board.

The light module 1 comprises a controller 8 capable of receiving an instruction to transmit a given photometric function and arranged to control, as a function of said instruction, the activation of the light source 2 for the emission of the light. light beam 10. For this purpose, the controller 8 comprises a device for controlling the power supply supplied to the light source 2 which is arranged to activate or deactivate this electric power supply or else to modify the value of the electric power supplied to the light source 2.

The light module 1 comprises an electrochromic device 9, arranged downstream of the light source 2, being disposed between the collector 3 and the inlet face 41 of the lens 4. The electrochromic device 9 has the form of a screen arranged generally in a plane crossed perpendicularly by the optical axis XX, so that this screen is crossed by the light beam 10 after reflection on the reflecting surface 6.

The electrochromic device 9 is formed by a stack of several layers including one or more of layers of electrochromic material, for example tungsten trioxide, encapsulated between layers forming electrodes and layers forming transparent substrates. In a known manner, the opacity of the layer or layers of electrochromic material can be modified when a power supply is applied to it or to them. In this way, the electrochromic device can have a transparent appearance in which it lets light pass through it without substantially deflecting this light or a diffuse appearance in which it diffuses this light. According to the invention, the appearance of the electro-chromic device 9 is controlled by the controller 8.

In the example shown, when the controller 8 receives an instruction to send a lighting function, it controls the electrochromic device 9 so that the latter has a transparent appearance and it controls the activation of the light source 2 for achieving the desired lighting function. For example, if the controller 8 receives a transmission instruction from a low beam type lighting function, it controls the activation of the light source 2 for the emission of the light beam 10 and the electro-chromic device 9 for that the latter has a transparent appearance.

[0072] [Fig. 2] is a graphic representation of the images projected by the light module of [Fig. 1] when the light source 2 is on and when the electrochromic device has a transparent appearance. The horizontal axis H and the vertical axis V intersect at the level of the optical axis of the light module. The curves shown are isolux, that is to say correspond to the zones of the light beam 10 which have the same illumination expressed in lux. The curves in the center correspond to a higher level of illumination than at the periphery.

It can be observed that the light beam 10 has an upper cut-off LB, essentially at the level of the horizontal axis H. This upper cut-off is a cut-off of the regulatory crossing type, produced by the rear edge 6.1 of the reflecting surface 6 of the collector 3, as shown in [Fig. 1] For this purpose, the focus 43 of the lens 4 is advantageously located near this edge 6.1, that is to say at the rear of the light source 2. Advantageously, the reflected light beam 10 by the reflecting surface 6 passes through the electrochromic device 9 before being projected by the lens 4. Due to the transparent appearance of the electrochromic device, the light beam 10 does not undergo any substantial deviation when passing through this electrochromic device 9, so that its photometric distribution, and in particular the upper cutoff, is not significantly modified by this electrochromic device. In this way, the light beam 10 performs a lighting photometric function of the regulatory crossing type.

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

In conjunction with [Fig. 3] and [Fig. 4], we will now describe the operation of the light module 1 under daytime conditions.

As shown in [Fig. 3], when the controller 8 receives an instruction to transmit a daytime signaling function, it controls the electrochromic device 9 so that the latter has a diffusing appearance and it controls the activation of the source 2 for the realization of. the desired signaling function. For example, if the controller 8 receives an instruction to transmit a function of the daytime running light or DRL type, it controls the activation of the light source 2 for the emission of the light beam 10. It will be noted that the light beam 10 reflected by the reflecting surface 6 of the collector 3 thus exhibits a substantially identical photometric distribution under day or night conditions.

Advantageously, the light beam 10 reflected by the reflecting surface 6 of the collector 3 passes through the electrochromic device 9 and undergoes, due to the diffusing aspect of the electrochromic device 9, a deflection which spreads its distribution vertically and horizontally. photometric. This modified beam 11 is thus projected by the projection lens 4 to perform another photometric function.

[0078] [Fig. 4] is a graphic representation of the images projected by the light module of [Fig. 3] when only the light source 2 is on and when the electrochromic device 9 has a diffusing appearance

It can be observed that the light beam 11 projected by the lens 4 after diffusion by the electrochromic device 9 is devoid of any upper cutoff and is significantly more spread than the crossing type beam shown in [Fig. 2] This photometric distribution is thus compatible with the regulatory requirements of the daytime running light type function.

It should be noted that this distribution can be obtained when the controller 8 controls the electric power supplied to the light source 2 at a value substantially equal to the nominal value of this light source.

There is shown in [FIG. 5] a light module according to another embodiment of the invention, in a first mode of operation.

The light module 1 comprises a first light source 2, a first collector 3 capable of reflecting the light rays emitted by the first light source to form a first light beam LB along an optical axis XX of the module, and a projection lens 4 of said beam. Other optical projection systems than the projection lens can be envisaged, such as in particular one or more mirrors. The light module 1 further comprises a second light source 2 'opposite, with respect to the optical axis XX, to the first light source 2 and a second collector 3' also op posed to the first collector 3 and able to reflect the light rays emitted by the second light source 2 'to form a second light beam HB along the optical axis XX of the module.

The light sources 2 and 2 'are advantageously of the semiconductor type, such as in particular a light emitting diode. Each of the light sources 2 and 2 'emits light rays in a half-space delimited by the main plane of said source, according to the example shown, in a main direction perpendicular to said plane and to the optical axis X-X.

Each of the collectors 3 and 3 'comprises a support 5 and 5', in the form of a shell or cap, and a reflecting surface 6 and 6 'on the inner face of the support 5 and 5'. The reflecting surfaces 6 and 6 'advantageously have a profile of the elliptical or parabolic type. At least one of them is advantageously a surface of revolution about an axis parallel to the optical axis. Alternatively, it may be a free-form surface or a swept surface or an asymmetric surface. It can also include several sectors. The collectors 3 and 3 'in the form of a shell or cap are advantageously made of materials having good heat resistance, for example glass or synthetic polymers such as polycarbonate PC or polyetherimide PEI. The expression “parabolic type” applies generally to reflectors the surface of which has a single focal point, that is to say a zone of convergence of light rays such as the light rays emitted by a light source placed at the center. level of this convergence zone are projected at great distance after reflection on the surface. Projected at a great distance means that these light rays do not converge on an area that is at least 10 times the dimensions of the reflector. In other words, the reflected rays do not converge towards a convergence zone or, if they converge, this convergence zone is located at a distance greater than or equal to 10 times the dimensions of the reflector. A parabolic type surface may or may not have parabolic portions. A reflector having such a surface is generally used alone to create a light beam. Alternatively it can be used as a projection surface together with an elliptical type reflector. In this case, the light source of the parabolic type reflector is the zone of convergence of the rays reflected by the elliptical type reflector.

Each of the light sources 2 and 2 'is arranged at a focal point of the corresponding reflecting surface 6 and 6' so that its rays are collected and reflected along the optical axis XX. The projection lens 4 has a first input face 41 of light rays corresponding to the first light beam LB, a second input face 41 'of light rays corresponding to the second light beam HB and a common output face 42 at the two entrance faces. The lens 4 can have a first focal point 43 and a second focal point 43 ', the first focal point 43 corresponding to the upper part of the lens 4 and the second focal point 43' corresponds to the lower part of the lens 4. Each of the first and second focal points 43 and 43 'in question is advantageously located on a zone situated between the reflecting surface 6/6' of the first or second collector 3/3 'corresponding and the first or second light source 2/2' corresponding (these zones are delimited by the dotted lines). In this case at least one of the focal points may be located on the reflecting surface 6/6 'of the corresponding first or second 3/3' collector. It should be noted that it is also possible that this focus is located behind or in front of the 6/6 'reflection surface as long as it is close, preferably less than 10 mm, preferred. essentially less than 5 mm.

Still with reference to Figure 1, it can be observed 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 XX. In particular, the first light source 2 is disposed on one face of a support 7 and the second light source 2 'is disposed on an opposite face of the support 7. For example, each light source can be placed on a plate, for example a printed circuit board, which is specific to it, each plate being attached to the same heat sink. As a variant, the first and second light sources could be placed on opposite faces of a common plate.

The light module 1 comprises a controller 8 capable of receiving an instruction to transmit a given photometric function and arranged to control, as a function of said instruction, the activation of the first light source 2 and / or of the second light source 2 'for the emission of the first light beam LB and / or of the second light beam HB. To this end, the controller 8 comprises a device for controlling the electric power supplied to the light sources 2 and 2 'and is arranged to activate or deactivate this electric power supply or else to modify the value of the electric power supplied to the light sources 2 and 2 '.

The light module 1 comprises an electrochromic device 9, arranged downstream of the light sources 2 and 2 'being arranged between the collectors 3 and 3' and the input faces 41 and 41 'of the lens 4. The electrochromic device 9 has the form of a screen arranged generally along a plane crossed perpendicularly by the optical axis XX, so that this screen is crossed by the light beams LB and HB before these beams enter the lens 4. More precisely, the electrochromic device 9 comprises a first portion 91 and a second portion 92, arranged on either side of the optical axis XX, so that the first portion 91 either crossed substantially by the light beam LB and that the second portion 92 is crossed substantially by the light beam HB, without it being excluded that certain light rays emitted by one of the light sources 2 and 2 'respectively pass through the second portion 92 and the first portion 91.

Each of the layers 91 and 92 of the electrochromic device 9 is formed by a stack of several layers including one or more of layers of electrochromic material, for example tungsten trioxide, encapsulated between layers forming electrodes and layers forming transparent substrates. In a known manner, the opacity of the layer or layers of electrochromic material can be modified when a power supply is applied to it or to them. In this way, each layer 91 and 92 of the electrochromic device can have a transparent appearance in which it allows light to pass through it without substantially deviating this light or a diffusing appearance in which it diffuses this light. According to the invention, the appearance of each of the layers 91 and 92 of the electrochromic device 9 is controlled independently by the controller 8, as a function of the transmission instruction received.

In the operating mode shown in [Fig. 5], the controller 8 receives an instruction to send a crossing type lighting function. In response, it checks the first layer 91 of the electrochromic device 9 so that it has a transparent appearance and the second layer 92 so that it has a diffusing appearance. The controller also controls the activation of the first source 2 by supplying it with an electric power of a value substantially identical to its nominal value as well as the activation of the second source 2 'by supplying it with an electric power of a value substantially lower than its value. nominal.

[0093] [Fig. 6] is a graphic representation of the images projected by the light module 1 in the operating mode of [Fig. 5]. The horizontal axis H and the vertical axis V intersect at the level of the optical axis of the light module. The curves shown are isolux, that is to say correspond to the zones of the light beam projected by the lens 4 which have the same illumination expressed in lux. The curves in the center correspond to a higher level of illumination than at the periphery.

It can be observed that the first light beam LB has an upper cut-off, essentially at the level of the horizontal axis H. This upper cut-off is a cut-off of the regulatory crossing type, produced by the rear edge 6.1 of the reflecting surface 6 of the first collector 3, as shown in [Fig. 5]. For this purpose, the first hearth 43 of the lens 4 is advantageously located near this edge 6.1, that is to say at the rear of the first light source 2. Advantageously, the first light beam LB passes through the portion 92 of the electrochromic device 9 without be substantially deflected in any way, then enters lens 4 through entry face 41 and is thrown onto the road. It is thus noted that its photometric distribution, and in particular the upper pure neck, is not substantially modified by this electrochromic device, and thus makes it possible to perform a first photometric function, namely lighting of the crossing type.

Furthermore, parasitic rays of the first light beam LB which reach the second portion 92 are diffused by this second portion, so that even if some of these rays are projected by the lens 4 above the upper cutoff , their intensity is reduced by this diffusion so that they are not dazzling.

In addition, the second light beam HB emitted by the second light source 2 'and reflected by the second collector 3' has a reduced intensity given the reduced value of the power supply the second light source 2 'receives . This second light beam is intercepted by the second portion 92 and is also spatially spread, due to the diffusing aspect of this second portion. Consequently, the light beam HB enters the lens 4 via the entry face 41 'and is projected above the upper cut-off of the beam LB, but with an intensity such that it is not dazzled, of so that the overall beam projected by the lens complies with the regulatory requirements of the passing-type lighting function. As such, neither the parasitic rays nor the light beam HB have been shown in [Fig. 6] Finally, it can be seen that the exit face 42 of the lens 4 is totally illuminated by the beams LB and HB.

There is shown in [FIG. 7] a second mode of operation of the light module 1 of [Fig. 5], in which the controller 8 receives an instruction to send a lighting function of the road type. In response to this instruction, it checks the first layer 91 of the electrochromic device 9 so that it has a transparent appearance and the second layer 92 so that it also has a transparent appearance. The controller also controls the activation of the first source 2 by supplying it with an electric power of value substantially identical to its nominal value as well as the activation of the second source 2 'by supplying it with an electric power of value substantially identical to its value. nominal.

[0098] [Fig. 8] is a graphic representation of the images projected by the light module 1 in the operating mode of [Fig. 7]

The second light beam HB extends substantially above the upper cut-off of the beam LB, so as to complete this first light beam LB. This concentration of light above the upper cutoff is achieved by the part of the reflective surface 6 'which is close to the trailing edge 6.1'. For this purpose, the second focal point 43 ′ of the lens 4 can be located near the rear edge 6.1 ′. Each light beam LB and HB thus passes through the first layer 91, respectively the second layer 92, of the electrochromic device 9 without undergoing any substantial deviation, and thus penetrates through the entry face 41, respectively 41 ', of the lens 4 to be projected onto the road. . The combination of the first and second light beams LB and HB thus together form a beam which complies with the regulatory requirements of the road-type lighting function. The light module 1 thus performs a second photometric function, namely road-type lighting. It is noted that, moreover, that the exit face 42 of the lens 4 is totally illuminated by the beams LB and HB.

[0100] There is shown in [FIG. 9] a third mode of operation of the light module 1 of [FIG. 5], in which the controller 8 receives an instruction to send a signaling function of the daytime running light type. In response to this instruction, it checks the first layer 91 of the electrochromic device 9 so that it has a diffusing appearance and the second layer 92 so that it also has a diffusing appearance. The controller also controls the activation of the first source 2 by supplying it with an electric power of value substantially identical to its nominal value as well as the activation of the second source 2 'by supplying it with an electric power of value substantially identical to its value. nominal.

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

Advantageously, each of the first and second light beams LB and HB passes through the portion 91, respectively 92, of the electrochromic device 9 and undergoes, due to the diffusing aspect of this portion, a deflection spreading out vertically and horizontally its photometric distribution, then enters the lens 4 through the entry face 41, respectively 41 ', to be projected. The set of two projected beams thus forms a DRL beam.

[0103] [Fig. 10] is a graphic representation of the images projected by the light module 1 in the operating mode of [Fig. 9]

[0104] It can be observed that the light beam DRL projected by the lens 4 is devoid of any upper cutoff and is appreciably more spread out than the beam of the crossing type shown in [FIG. 6] or the high beam type beam shown in [Fig. 8] This photometric distribution is thus compatible with the regulatory requirements of the daytime running light type function. The light module 1 thus performs a third photometric function, namely a daytime running light. It can be seen that, in this third mode of function, the exit face 42 of the lens 4 is totally illuminated by the beams LB and HB.

[0105] It will thus be understood that, thanks to the invention and in particular thanks to the use of an electrochromic device, the appearance of which is controlled as a function of the desired photometric function, the light module has a light signature, c 'that is to say an aspect on, constant, day and night, while allowing day and night pho tometric functions to be performed in accordance with the regulatory requirements for these functions. Likewise, thanks to the invention and in particular thanks to the use of an electro-chromic device with two layers, the appearance of which is independently controlled as a function of the desired photometric function, the light module has a light signature, c That is to say, an appearance that is lit, constant, day and night, while making it possible to perform photometric lighting and signaling functions and while remaining compact overall.

In any event, the invention cannot be limited to the embodiments specifically described in this document, and extends in particular to all equivalent means and to any technically operative combination of these means. In particular, it will be possible to envisage arranging the electrochromic device differently from the manner described, for example by placing it downstream of the projection lens. It is also possible to envisage using the light module described for other daytime and nighttime functions than those described, for example for lighting functions of the crossing type or of the segmented or pixelated road type. It is also possible to envisage using the light module described for other daytime and night-time functions than those described, for example for lighting functions of the intersection or segmented or pixelated road type and for signaling functions of the traffic light type. position or direction indicator. Furthermore, it is possible to envisage integrating an electrochromic device in a light module having an optical structure different from that described, and in particular in a light module comprising a matrix of light sources each associated with a primary optic, for example of the collimator type or microlens, the assembly being combined with an optical projection system, for example formed of a succession of field and projection lenses.

Claims

[Claim 1] Light module (1) of a lighting device of a motor vehicle, comprising: a. a light source (2, 2 ') intended to participate in the production of at least one photometric function, b. an electrochromic device (9) comprising at least one portion (91, 92) arranged downstream of the light source (2, 2 ') and able to selectively present a diffusing appearance and a transparent appearance; and c. a controller (8) arranged to receive an instruction to transmit said photometric function and to control, as a function of said instruction, the emission of light by the light source (2, 2 ') and the appearance of the electrochromic device ( 9).

[Claim 2] Light module (1) according to the preceding claim, in which the light source (2) is intended to participate in the realization of at least a first photometric function and a second photometric function and in which the controller (8) is arranged to receive an emission instruction from one or other of the first and second photometric functions and to control, as a function of said instruction, the emission of light by the light source (2, 2 ') and the appearance of the electrochromic device (9).

[Claim 3] Light module (1) according to the preceding claim, in which the first photometric function is a regulatory daytime running light and in which the second photometric function is a lighting function of the regulatory road, and in which the controller (8 ) is arranged to control the electrochromic device (9) so that the electrochromic device (9) has a diffusing appearance when receiving an instruction to transmit the first photometric function and so that the electrochromic device (9) has a transparent appearance when receiving an instruction to send the second photometric function.

[Claim 4] Light module (1) according to one of the preceding claims, the light module (1) comprising an optical projection device (4) arranged to receive light (10) emitted by the light source (2, 2) ') and to project this light on the road, in which the electrochromic device (9) is arranged downstream of the optical projection device (4).

[Claim 5] Light module (1) according to one of claims 1 to 3, the light module comprising an optical collecting device (3, 3 ') arranged to collect the light emitted by the light source (2, 2' ) into an intermediate light beam (10) and an optical projection device (4) arranged to receive the intermediate light beam and project it onto the road, in which the electrochromic device (9) is arranged between the collection optical device (B, 3 ') and the projection optical device (4).

[Claim 6] A light module (1) according to the preceding claim, wherein the collecting optical device (3, 3 ') has a reflecting surface (6, 6') configured to collect and reflect the light rays emitted by the light source. (2, 2 '); the projection optical system (4) being configured to project the light rays reflected from the reflecting surface in a light beam (10, 11) along an optical axis (X-X) of the device; the light beams performing the first photometric function when the electrochromic device (9) has a diffusing appearance and the second photometric function when the electrochromic device (9) has a transparent appearance.

[Claim 7] Light module (1) according to claim 1, wherein the light source is a first light source (2), the portion of the electrochromic device is a first portion (91) of the electrochromic device, characterized in that it comprises: d. a second light source (2 '), each of the first (2) and second light sources (2') being intended to participate in the realization, respectively, of a first and a second photometric function; e. an optical projection device (4) configured to project the light rays emitted by the first (2) and second light sources (2 '), respectively, into a first light beam (10) and a subsequent second light beam (11) an optical axis (XX) of the device; f. a second portion (92) arranged downstream of the second light source (2 '), the second portion (92) being able to selectively present a diffusing appearance and a transparent appearance; and and in that the controller (8) is arranged to receive an instruction to transmit one or the other of the first and second photometric functions and to control, as a function of said instruction, the emission of light by the first light source (2) and / or by the second light source (2 ') and the appearance of the first and / or of the second portion of said electrochromic device.

[Claim 8] Light module (1) according to the preceding claim, in which: a. the first light source (2) and the second light source (2 '), each of the first (2) and second light sources (2') being intended to participate in the production, respectively, of a first and a second photometric function; b. an optical projection device (4) configured to project the light rays emitted by the first (2) and second light sources (2 '), respectively, into a first light beam (10) and a subsequent second light beam (11) an optical axis (XX) of the device (4); vs. an electrochromic device (9) comprising a first portion (91) arranged downstream of the first light source (2) and a second portion (92) arranged downstream of the second light source (2 '), each of the first and second portions (91, 92) being able to selectively present a diffusing appearance and a transparent appearance; and D. a controller (8) arranged to receive an emission instruction from one or other of the first and second photometric functions and to control, as a function of said instruction, the emission of light by the first light source (2) and / or by the second light source (2 ') and the appearance of the first (91) and / or of the second portion (92) of said electrochromic device (9).

[Claim 9] Light module (1) according to the preceding claim, in which the controller (8) is arranged to control, on receipt of an instruction to transmit the first photometric function, the emission of light by the first. light source (2), the first light beam (10) performing the first photometric function.

[Claim 10] Light module (1) according to the preceding claim, wherein the controller (8) is arranged to control the electrochromic device (9) so that the first portion (91) has a transparent appearance and so that the second portion (92) has a diffusing appearance when receiving an instruction to send the first photometric function.

[Claim 11] Light module (1) according to one of claims 7 to 10, in which the controller (8) is arranged to control, on receipt of an instruction to transmit the second photometric function, the transmission. simultaneous light by the first light source (2) and by the second light source (2 '), the first and second light beams (10, 11) together performing the second photometric function.

[Claim 12] Light module (1) according to the preceding claim, wherein the controller (8) is arranged to control the electrochromic device (9) so that the first portion (91) and the second portion (92) have an appearance. transparent when receiving an instruction to send the second photometric function.

[Claim 13] Light module (1) according to one of claims 7 to 12, wherein the first light source (2) and the second light source (2 ') are intended to participate together in the realization, respectively, of a third photometric function, and in which the controller (8) is arranged to control, on receipt of an instruction to transmit the third photometric function, the simultaneous transmission of light by the first light source (2) and by the second light source (2 '), the first and second light beams (10, 11) together performing the second photometric function; and the electrochromic device (9) so that the first portion (91) and the second portion (92) have a diffusing appearance.

[Claim 14] Light module (1) according to the preceding claim, in which the first photometric function is a lighting function of the regulatory crossing type, the second photometric function is a lighting function of the regulatory road type, and in which the third photometric function is a regulatory daytime running light type signaling function.

[Claim 15] Light module (1) according to one of claims 7 to 14, the light module comprising a first optical collection device (3) and a second optical collection device (3 '), each optical collection device being arranged to collect the light rays (LB, HB) emitted, respectively, by the first and the second light source (2, 2 '); the projection optical device (4) being arranged to receive the light rays collected by the collection optical devices (3, 3 '), the electrochromic device (9) being arranged between the collection optical devices (3, 3') and the optical projection device (4).

[Claim 16] A light module (1) according to the preceding claim, in which the optical projection device (4) comprises a lens comprising a first input face (41) for receiving the light rays (10) emitted by the first source. light (2) and a second input face (41 ') for receiving the light rays (11) emitted by the second light source (2), the first portion (91) of the electrochromic device (9) being arranged in a vis- vis-à-vis the first input face and the second portion (92) of the electrochromic device being arranged opposite the second input face.

[Claim 17] A device for lighting a motor vehicle, comprising a light module (1) according to one of the preceding claims.