Lighting and signaling device for a motor vehicle

Abstract

The invention mainly relates to a lighting and signalling device (1) comprising: at least one lighting module (4) capable of generating a lighting beam (A) along a longitudinal optical axis; and an optical element (2) through which the illumination beam (A) is projected, characterised in that the illumination and signaling device (1) comprises a controllable liquid crystal screen (18) pressed against the optical element (2), the controllable liquid crystal screen (18) being able to assume different diffusion states including at least: a projection state of the illumination beam (A) in which the controllable liquid crystal screen (18) is transparent; and a signalling beam emission state in which the controllable liquid crystal screen (18) is at least partially diffuse.

Description

[0001] The invention relates to the field of lighting and / or signalling in the automotive field.

[0002] The field of lighting and / or signalling in motor vehicles is governed by regulations which stipulate that every motor vehicle must be equipped with lights to perform specific safety functions, in particular with signalling lights, high beam and low beam. Signalling lights are generally used to convey information to other road users but do not have any function of illuminating the road for the driver of the vehicle, such as direction indicators or daytime running lights (DRL). Low beam allows the driver of a motor vehicle to be seen by other road users and allows its driver to see the road correctly at a distance of 30 metres without dazzling other road users. High beam allows the driver to see the road correctly at a distance of 100 metres, but may dazzle other road users and should only be used outside built-up areas and when there are no users in front of the motor vehicle.

[0003] In order to make the lighting device of a motor vehicle compact, it is sought to combine individual devices allowing these signaling functions and these lighting functions to be performed in a single headlamp, and the motor vehicle manufacturer or equipment manufacturer may in particular seek to have a common optical element for each of these functions, for example in the form of a transparent or translucent screen which closes the housing of the headlamp and from which the light forming one or the other of the lighting beam or the signaling beam emerges.

[0004] In the context of such a common optical element, it is also sought that the extent of the lighting surface is equal in each function, in particular for the aesthetics and visual recognition of the lighting device. However, this is difficult to achieve, since the lighting function and / or the signaling function have different characteristics, the lighting beam must be directional, while the signaling beam is diffuse. The presence of a diffuser for generating the signaling beam may interfere with the propagation of the light rays intended to form the prescribed lighting beam.

[0005] In this context, the present invention proposes a lighting and signaling device, which includes: at least one light-emitting module, which is suitable for generating an illumination beam along a longitudinal optical axis; and an optical element, through which the illumination beam is projected. It is worth noting that the lighting and signaling device includes a controllable liquid crystal screen pressed against the optical element, which is suitable for presenting different diffusion states, which at least include: an illumination beam projection state, in which the controllable liquid crystal screen is transparent; and a signaling beam emission state, in which the controllable liquid crystal screen is at least partially diffuse.

[0006] Such a lighting and signaling device can be mounted on a vehicle to function, for example, as a signaling light, a low beam and / or a high beam, thereby allowing a lighting beam or a signaling beam to be produced on the same display surface without the signaling light interfering with the intended operation of the high beam or low beam, thereby affecting the illumination of a road for a vehicle equipped with the lighting and signaling device.

[0007] In the lighting and signaling device according to the invention, the light module is configured to generate a lighting beam projected toward the optical element. It should be noted that when the lighting and signaling device is installed on a motor vehicle, it is this lighting beam that is used to generate a low beam beam and / or a high beam beam.

[0008] Furthermore, the lighting and signalling device comprises a housing in which the light module is mounted, the optical element possibly forming, for example, an element for closing said housing. In other words, the optical element contributes to forming one of the walls of the housing in which the light module is housed, the light module projecting a lighting beam through the optical element onto the road.

[0009] A controllable liquid crystal screen is fixed to the optical element to form an optical unit which can strongly diffuse the illumination beam passing through the optical element or, on the contrary, can weakly diffuse it.

[0010] Furthermore, "transparent" means that the controllable liquid crystal screen is able to allow light beams to pass through without causing any significant disturbance to the light beams when passing through the controllable liquid crystal screen, for example, except for Fresnel reflections.

[0011] Furthermore, the state of the controllable liquid crystal screen can be defined according to the haze factor of the controllable liquid crystal screen. For example, in the projection state, the controllable liquid crystal screen has a low haze factor, for example less than 6%. Advantageously, when the controllable liquid crystal screen is in the projection state, the haze factor of the screen is about 3%.

[0012] Conversely, in the signaling beam emitting state, the controllable liquid crystal screen has a haze factor of high value, for example greater than 90%. Advantageously, when the controllable liquid crystal screen is in the emitting state, the haze factor of said screen is about 98%.

[0013] According to an optional feature of the invention, the controllable liquid crystal screen is placed between the optical element and the light module. The controllable liquid crystal screen is advantageously placed between the light module and the optical element so that when the optical unit as a whole is transparent, the illumination beam generated by the light module passes successively through the controllable liquid crystal screen and the optical element.

[0014] The present invention may include one or more of the features described below, which may be implemented alone or in combination with other features.

[0015] According to an optional feature of the invention, the controllable liquid crystal screen is attached to the optical element by an adhesive bond.

[0016] According to an optional feature of the invention, the controllable liquid crystal screen is attached to the optical element by means of an optical adhesive. The term "optical adhesive" means a transparent adhesive having an optical refractive index close to that of at least one of the adhesively bonded elements, in this case the controllable liquid crystal screen and / or the optical element.

[0017] According to an optional feature of the invention, the controllable liquid crystal screen is attached to the optical element by overmoulding.

[0018] According to an optional feature of the invention, a controllable liquid crystal screen comprises two transparent walls, a polymer matrix extending between the two transparent walls and interspersed with liquid crystals, and two electrodes, each associated with one of the transparent walls, to pass an electric current through the polymer matrix and its liquid crystals.

[0019] According to an optional feature of the invention, at least one wall comprises a conductive layer in direct contact with the polymer matrix and an electrically insulating layer arranged to cover the conductive layer on the opposite side of the polymer matrix. The conductive layer may be formed of indium tin oxide (ITO) and the insulating layer may be formed of polycarbonate (PC) or polyethylene terephthalate (PET).

[0020] According to an optional feature of the invention, the controllable liquid crystal screen comprises an inner transparent wall facing the lighting module and an outer transparent wall facing the external environment of the lighting and signalling device, the optical element constituting the outer transparent wall.

[0021] According to an optional feature of the invention, the lighting and signaling device comprises a control member for controlling a controllable liquid crystal screen, the control member being configured to supply power to the controllable liquid crystal screen so that the controllable liquid crystal screen changes from a projection state to a signaling beam emission state, or from a signaling beam emission state to a projection state, depending on a change in the power supply. When power is supplied to the controllable liquid crystal screen, and more particularly when power is supplied to the polymer matrix via the electrodes, the liquid crystals embedded in the polymer matrix are all oriented parallel to the direction of the current passing through the polymer matrix, i.e. perpendicular to the transparent walls of the screen. In this configuration, the light beam is able to pass through the controllable liquid crystal screen without being deflected by the liquid crystals, which are arranged along the main propagation direction of the light beam in such a way that a prescribed illumination beam is formed.

[0022] According to another example of the invention, the liquid crystals are naturally oriented in a manner that allows a light beam to pass through the controllable liquid crystal screen without power. In this example of the invention, when power is supplied to the controllable liquid crystal screen, and more particularly when power is supplied to the polymer matrix via electrodes, the liquid crystals embedded in the polymer matrix are all randomly oriented in a manner that causes the light beam to diffuse when passing through the controllable liquid crystal screen.

[0023] According to an optional feature of the invention, the control member is electrically connected to each of the electrodes of the controllable liquid crystal screen.

[0024] According to an optional feature of the invention, the lighting and signalling device comprises a main light source which is part of the lighting module and an additional light source which is mounted facing the optical element.

[0025] According to an optional feature of the invention, the primary light source is configured to contribute to generating a light beam intended to pass through an optical unit formed by the controllable liquid crystal screen and the optical element, the light beam being able to form an illumination beam or a signaling beam depending on the diffusion state of the controllable liquid crystal screen.

[0026] According to an optional feature of the invention, the additional light source is configured to assist in generating the signalling beam.

[0027] According to an optional feature of the invention, the main light source and the additional light source are supplied with power simultaneously or individually.

[0028] According to an optional feature of the invention, the optical element has an inner face in contact with the controllable liquid crystal screen, an opposite outer face, and a peripheral edge connecting the inner face to the outer face, the additional light source being mounted facing the peripheral edge of the optical element.

[0029] According to an optional feature of the invention, the controllable liquid crystal screen comprises a first portion and a second portion extending around a periphery of the first portion, the diffuse state of one of the portions of the controllable liquid crystal screen being independent of the diffuse state of another of the portions.

[0030] According to an optional feature of the invention, the first part is powered independently of the second part by the control means.

[0031] According to an optional feature of the invention, the lighting and signalling device comprises a light diffusing element arranged facing the second portion of the controllable liquid crystal screen.

[0032] According to an optional feature of the invention, the diffusing element comprises a film mounted between the controllable liquid crystal screen and the optical element.

[0033] According to an optional feature of the invention, the optical element comprises a main area facing the first portion of the controllable liquid crystal screen and a main area peripheral area facing the second portion of the controllable liquid crystal screen, the diffusing element constituting the peripheral area of ​​the optical element.

[0034] According to an optional feature of the invention, the lighting and signalling device comprises a masking member arranged to cover a periphery of the outer face of the optical element.

[0035] The invention also relates to a motor vehicle equipped with at least one lighting and signaling device as described above.

[0036] Further characteristics, details and advantages of the invention will become more apparent from reading the following description on the one hand and a number of embodiments provided as non-limiting indications on the other hand, with reference to the attached schematic drawings, in which:

[0037] [ Figure 1 ] schematically depicts a first embodiment of a lighting and signalling device according to the invention having an optical unit formed by an optical element and a controllable liquid crystal screen in a first configuration in which at least a portion of the controllable liquid crystal screen is in a projecting state, in other words a state referred to as transparent;

[0038] [ Figure 2 ] schematically depicts the second configuration Figure 1 The first embodiment of the lighting and signalling device shown, in this second configuration, the controllable liquid crystal screen is in a signalling beam emission state, in other words a state referred to as diffuse;

[0039] [ Figure 3 ] schematically depicts a third configuration Figure 1 The first embodiment of the lighting and signalling device shown, in this third configuration, the controllable liquid crystal screen is in a signalling beam emission state, in other words a state referred to as diffuse;

[0040] [ Figure 4 ] schematically depicts a second embodiment of a lighting and signalling device according to the invention;

[0041] [ Figure 5 ] schematically depicts a third embodiment of a lighting and signaling device according to the present invention.

[0042] The features, variants and different embodiments of the present invention can be associated with each other according to various combinations, as long as they are not incompatible or mutually exclusive. In particular, it is conceivable that the variants of the present invention only include the selection of features described below in isolation from other features described, provided that such selection of features is sufficient to provide technical advantages and / or distinguish the present invention from the prior art.

[0043] In the figures, elements common to several figures retain the same reference numerals.

[0044] Figure 1 A lighting and signaling device 1 according to the invention is shown, which is fitted in a motor vehicle and is configured in particular to generate an illumination beam or signaling beam A predominantly along a longitudinal optical axis L.

[0045] The lighting and signalling device 1 comprises an optical element 2 through which a light beam A is projected to form a lighting beam suitable for illuminating a road. The optical element 2 thus forms a luminous surface of the lighting and signalling device, the shape and dimensions of which influence the visual recognition of the function.

[0046] The lighting and signalling device 1 comprises a lighting module 4 configured to generate a light beam A and direct it towards the optical element 2 , it being understood that the lighting module 4 may project a light beam suitable for forming a low beam lighting function and / or a high beam lighting function.

[0047] According to the present invention, Figures 1 to 5 As can be seen in FIG. 1 , the lighting and signaling device 1 comprises a controllable liquid crystal screen 18 pressed against the optical element 2 to form an optical unit arranged in the direction in which the light beam A is directed when the light module 4 is activated. The controllable liquid crystal screen 18 is arranged between the optical element 2 and the light module 4 so that the optical element is turned toward the outside of the lighting and signaling device and forms a light-emitting surface of the device.

[0048] As will be described in more detail below, controlling the controllable liquid crystal screen 18 makes it possible to modify its diffusion state and the overall diffusion state of the optical unit, and therefore to modify the effect that the optical unit can have on the projection of a light beam towards the road. In other words, the lighting module is intended to project a light beam through the optical unit which deflects the light beam only slightly or not at all, if the controllable liquid crystal screen 18 is transparent, or deflects the light beam and is therefore diffused, if the controllable liquid crystal screen 18 is diffuse.

[0049] like Figure 1 As shown, the lighting and signaling device 1 comprises a housing 6 to which an optical element 2, more particularly an optical unit formed by an optical element and a controllable liquid crystal screen 18, is attached, and in which a light module 4 is housed. The optical element 2 forms at least a part of one of the walls of the housing 6, having an external face 8 oriented toward the outside of the lighting and signaling device 1, and an internal face 10 that contributes to at least partially delimiting a housing for the light module 4. The optical element 2 is, for example, a transparent screen through which the light beam A is adapted to pass in order to be projected. The optical element 2 is optically neutral, that is to say, it does not deflect light, without, however, constituting a limitation of the invention.

[0050] like Figures 1 to 5 As can be seen in FIG, the lighting and signaling device 1 comprises a main light source constituting a lighting module 4, and an additional light source 12 mounted facing the optical element 2. In this case, the main light source is configured to contribute to forming a light beam A, while the additional light source 12 is configured to contribute to forming a signaling beam.

[0051] The primary light source (not visible in the figures as it is housed in the housing of the lighting module) is for example formed by one or more light emitting diodes (commonly referred to as LEDs) and is configured to generate light.

[0052] The light emitting module 4 may further include an optical member in addition to the main light source, and the main light source is configured to emit light toward the optical member.

[0053] The optical member is configured to gather the light emitted by the main light source to form a light beam A in the direction of at least the optical element 2 .

[0054] The optical component may consist of a projection lens.

[0055] The optical member may further include a reflector or a reflective element arranged facing the main light source, the reflector having a function of guiding the light emitted by the main light source toward the projection lens.

[0056] Alternatively, the optical member may include a reflector having a function of directing the light emitted by the primary light source toward the optical element 2 .

[0057] In general, the optical component can include one or more reflectors, one or more lenses, and any combination of one or more reflectors and one or more lenses.

[0058] The additional light source 12 is arranged to face the lateral edge 16 of the optical element 2. The lateral edge 16 of the optical element 2 is the face of the optical element 2 that connects the inner face 10 and the outer face 8 of the optical element 2 at the periphery. In other words, the additional light source 12 projects light rays from the edge face of the optical element in the optical element 2, which are initially substantially perpendicular to the above-mentioned and at the end of the optical element 2 by continuous total reflection in the optical element 2. Figure 2 The continuous total reflection of the light generated by the additional light source 12 continues to propagate in the optical element 2 until it encounters a diffusing element which deflects the path of the light at an appropriate angle towards the outer face 8 to be refracted towards the road and to contribute to the generation of a signaling beam for other road users.

[0059] The main light source and the additional light source 12 may be powered simultaneously or individually, and the powering of each light source depends on the diffusion state of the controllable liquid crystal screen 18 .

[0060] The controllable liquid crystal screen 18 may be attached to the optical element 2 by adhesive bonding, using an adhesive that may be applied between the controllable liquid crystal screen 18 and the optical element 2, for example, applied to the periphery of the contact surface between the controllable liquid crystal screen 18 and the optical element 2, or alternatively, the controllable liquid crystal screen may be attached to the optical element 2 by overmolding. This alternative makes it possible to rigidly fix the controllable liquid crystal screen 18 to the optical element 2 without inserting an adhesive between the controllable liquid crystal screen 18 and the optical element 2, which may have minimal effect on the propagation of light emitted by the light emitting module through the optical unit formed by the controllable liquid crystal screen 18 and the optical element 2.

[0061] The controllable liquid crystal screen 18 makes it possible to adjust the diffusion level of the optical unit formed by it and the optical element 2, so that the light beam A passing through the optical unit is diffused or not diffused, or to form a diffusing screen facing the inner face of the optical element 2 and promote the light emitted on the edge face of the light guide formed by the optical element to be emitted towards the road in the form of a signaling beam.

[0062] To this end, the controllable liquid crystal screen 18 is arranged between the light module 4 and the optical element 2, so that when the controllable liquid crystal screen 18 is configured accordingly, it contributes to forming the diffusing surface of the optical element on the opposite side of the road. Note that, with this arrangement, when the controllable liquid crystal screen is configured to be transparent to allow light to pass through, the light beam A passes through the controllable liquid crystal screen 18 and then passes through the optical element 2.

[0063] According to the present invention, the controllable liquid crystal screen 18 is suitable for presenting different diffusion states, which at least include: a projection state, which allows the light beam A to be projected through the optical unit to form an illumination beam emitted from the optical unit, and in this projection state, the controllable liquid crystal screen 18 is transparent; and a signaling beam emission state, in which the controllable liquid crystal screen 18 is opaque.

[0064] The projection state of the controllable liquid crystal screen 18 is associated with the emission of a light beam A by the light-emitting module and the use of the light beam A to generate a low-beam or high-beam type lighting function, while the emission state of the controllable liquid crystal screen 18 is associated with the emission of the light beam A and its transformation through diffusion, or with the emission of light directly in a light guide formed by an optical element by using an additional light source.

[0065] These different states of the controllable liquid crystal screen 18 are defined according to the haze factor that said controllable liquid crystal screen 18 has in each of these states, the haze factor corresponding to the percentage of light rays that manage to pass through the objects it encounters.

[0066] For example, in the illumination beam projection state, the controllable liquid crystal screen 18 has a low value of haze factor, for example less than 6%. Advantageously, when the controllable liquid crystal screen 18 is in the projection state, the haze factor of said screen 18 is about 3%.

[0067] Conversely, in the signaling beam emission state, the controllable liquid crystal screen is in a non-diffuse state, in other words it has a high value of haze factor, for example greater than 90%. Advantageously, when the controllable liquid crystal screen 18 is in the emission state, the haze factor of said screen is about 98%.

[0068] The haze factor of the controllable liquid crystal screen 18 is modified by modifying the power supply to the screen, which has the effect of modifying the orientation of the liquid crystals within the screen so that light passing through the screen is deflected more or less by those liquid crystals.

[0069] More specifically, the controllable liquid crystal screen 18 comprises two transparent walls 20, 22 and a polymer matrix 24 in which the liquid crystals are randomly dispersed and which extends between the two transparent walls 20, 22. The controllable liquid crystal screen also comprises electrodes connected to each of the transparent walls 20, 22, respectively, to allow the passage of electric current within the controllable liquid crystal screen, more specifically, to allow the passage of electric current from one transparent wall to the other through the polymer matrix. Each of these walls may in particular comprise two layers superimposed on each other, respectively: a conductive layer, for example formed of indium tin oxide (ITO), in direct contact with the polymer matrix; and an electrically insulating layer, for example formed of polycarbonate (PC), arranged to cover the conductive layer on the side opposite to the polymer matrix.

[0070] The controllable liquid crystal screen 18 comprises more particularly an inner transparent wall 20 facing the light module 4 and an outer transparent wall 22 facing the external environment of the lighting and signaling device 1, against which the optical element 2 bears. Where appropriate, and if the manufacturing method allows, the optical element 2 may form the outer transparent wall 22, more particularly its electrically insulating layer.

[0071] The lighting and signaling device 1 comprises a control member 28 for controlling the controllable liquid crystal screen 18, intended to control the supply of electricity to the controllable liquid crystal screen 18 via a power supply cable 26 and electrodes schematically shown in the drawing. The control member 28 is configured to supply power to the controllable liquid crystal screen 18, more particularly to the polymer matrix 24 and to the liquid crystals embedded therein and initially randomly dispersed, in such a way that, when the screen is supplied with power, the liquid crystals are oriented in a direction parallel to the main direction of the current in the polymer matrix, so as to limit the influence of the liquid crystals on the light path. It will be understood that, when the controllable liquid crystal screen 18 is supplied with power, this results in an arrangement of the liquid crystals such that the screen is transformed from a diffuse state to a transparent state, in other words, in this case from a signaling beam emission state to an illumination beam projection state.

[0072] Where applicable, the controllable liquid crystal screen 18 can be imparted with intermediate states by adjusting the intensity of the electric current passed through the polymer matrix.

[0073] More specifically, the original state of the controllable liquid crystal screen 18 is a diffuse state, which corresponds to the state of the controllable liquid crystal screen 18 when the polymer matrix 24 and the liquid crystals embedded therein are not powered and the arrangement of the liquid crystals is random, so that light encountering and / or passing through the screen and the optical elements formed by the screen is reflected and refracted and presents a diffuse state.

[0074] As soon as the control member 28 supplies power to the polymer matrix 24, in particular via the electrodes and the cable 26, the liquid crystal becomes organized, in particular aligns itself vertically relative to the transparent wall carrying the electrodes, so that the controllable liquid crystal screen enters a projection state, and the light beam A is then able to pass through the controllable liquid crystal screen 18 in the direction of the optical element 2, so that the light beam can form a prescribed lighting beam on the road.

[0075] These two different diffusion states can be especially Figures 1 to 3 As can be seen in the figure, the controllable LCD screen 18 is Figure 1 is shown as partially transparent and partially opaque, in Figure 2 and Figure 3 is shown as being completely opaque.

[0076] Several embodiments of the present invention will now be described, including Figures 1 to 3 The first embodiment shown, Figure 4 The second embodiment shown and Figure 5 The third embodiment of the present invention is shown. Unless otherwise specified, each of the described embodiments can be implemented as an alternative or additional solution to one or more other embodiments. In addition, the items common to the various embodiments and the content described above will have the same reference numerals in the description of each of the following embodiments.

[0077] According to the first embodiment of the present invention, and as Figures 1 to 3 As more particularly shown in FIG. 1 , the controllable liquid crystal screen 18 comprises a first portion 30 and a second portion 32 extending around the periphery of the first portion 30, the diffusion state of one of the two portions being independent of the diffusion state of the other portion. In other words, the first portion 30 is powered by the control member 28 independently of the second portion 32, so that, depending on the use case, the same intensity of power supply can be sent to the two portions at the same time, or one of the two portions, in particular the second portion 32, can be unpowered while the first portion is powered.

[0078] The second portion 32 can be made electrically independent from the first portion 30 , in particular by laser cutting the surface of the transparent wall, which allows providing a separate power supply for each of the two portions.

[0079] The second portion 32 is formed at the periphery of the screen and has a size such that the light beam A emitted by the light emitting module 4 is substantially or completely projected onto the first portion 30 of the controllable liquid crystal screen 18 .

[0080] For example, in Figure 1 In the first configuration shown, the first portion 30 of the controllable liquid crystal screen 18 is powered so that the liquid crystal is oriented in the direction of the current flowing in the polymer matrix, so that the first portion 30 is in an illumination beam projection state, i.e., has high transparency. Also in the first configuration, the second portion 32 of the controllable liquid crystal screen is not powered so that the liquid crystal remains randomly dispersed in the polymer matrix of the second portion 32, and the second portion is in a beam emission state with low transparency, i.e., a diffuse state.

[0081] In this first configuration, the light beam A emitted by the light-emitting module is projected through the first portion 30 of the controllable liquid crystal screen 18. It should be understood that the first portion 30 of the controllable liquid crystal screen 18 and the optical element 2 form a component that does not deflect the light beam A, so that the lighting function of the light-emitting module (whether it is a low beam function or a high beam function) is not affected by the presence of the controllable liquid crystal screen 18 and can meet the specified standards.

[0082] It may also be provided that light is emitted by additional light sources in order to give the lighting and signalling device a more uniform appearance.

[0083] according to Figure 2In the second configuration shown, the first and second portions of the controllable liquid crystal screen 18 are each in a diffuse state, in other words, in a signaling beam emission state. Neither the first portion 30 nor the second portion 32 of the controllable liquid crystal screen 18 is powered by the control member 28, so that the liquid crystals present in each of these two portions remain in their original position, i.e. randomly dispersed in the polymer matrix, with different orientations from each other. In this second configuration, the lighting module 4 is not enabled, so that no light beam attempts to pass through the optical unit formed by the controllable liquid crystal screen 18 and the optical element 2. The lighting and signaling device 1 of the invention does not perform a lighting function.

[0084] On the contrary, the additional light source 12 arranged facing the edge face of the optical element 2 is activated in such a way that it emits light in the thickness of the optical element. Figure 2 As can be seen, the light encounters the diffusing element formed by the controllable liquid crystal screen 18 pressed against the inner face 10 of the optical element 2 in a diffusing state, and the light is then deflected and directed towards / away from the outer face 8 at an angle allowing it to diffract out of the optical element, thereby forming a signaling beam.

[0085] The diffuse state of the controllable liquid crystal screen 18 contributes to the generation of the signaling beam by activating the additional light source, such that, as described above, the diffuse state corresponds to the signaling beam emitting state.

[0086] A light module may also be provided to project a light beam to make the diffusion of light more uniform.

[0087] according to Figure 3 In the third configuration shown, the first part 30 and the second part 32 of the controllable liquid crystal screen 18 are still in a diffuse state. The third configuration is different from the second configuration in that the light module is enabled so that the light beam A passes through the first part 30 of the controllable liquid crystal screen 18, and a different Figure 1 Thus, the light beam A is deflected and diffused by the random arrangement of the liquid crystals to form a signaling beam emitted from the lighting and signaling device of the present invention.

[0088] According to an alternative configuration (not shown), the diffusion of the light beam A emitted by the lighting module and the diffusion of the light emitted by the additional light source can be combined to increase the intensity of the signalling beam generated by the lighting and signalling device.

[0089] Furthermore, in any configuration, the haze factor of the controllable liquid crystal screen 18 can adopt intermediate values, in particular by varying the intensity of the power supply for each configuration. The intensity of the power supply can also be varied depending on the concentration of the liquid crystals dispersed in the polymer matrix.

[0090] Alternatively, it can also be provided that only the second part 32 is powered, while the first part 30 is not powered. It should be understood that in this case, the first part 30 is in the emission state, while the second part 32 is in the projection state.

[0091] It may also be provided that the first part 30 and the second part 32 are each powered, each of the two parts then being in a projection state.

[0092] According to the second embodiment of the present invention, and as Figure 4 As can be seen in FIG. 1 , the lighting and signaling device 1 comprises a light diffusing element 34, which is arranged facing the second portion 32 of the controllable liquid crystal screen 18. For example, the diffusing element 34 is a film mounted between the controllable liquid crystal screen 18 and the optical element 2, the film of the light diffusing element 34 extending at the periphery of the optical element, so that the light propagating by successive reflections in the optical element and meeting the diffusing film is deflected and then meets the outer face 8 or the exit face of the optical element at a certain angle, so that the light can be refracted to leave the optical element and form a signaling beam in the direction of the external environment of the lighting and signaling device 1.

[0093] Therefore, the optical element 2 can be defined as including a main area of ​​the first portion 30 facing the controllable liquid crystal screen 18 and a main area peripheral area facing the second portion 32, and the diffusion element 34 constitutes the peripheral area of ​​the optical element 2. It should be understood that the diffusion element 34 is an integral part of the optical element 2 and can form a texture pattern, for example, at the periphery of the optical element 2 to diffuse the light passing through the optical element 2 at the periphery of the optical element.

[0094] It should be noted that the presence of the diffusing element 34 at the periphery of the optical element 2 is not incompatible with the various configurations mentioned above with reference to the first embodiment.

[0095] According to the third embodiment, and as Figure 5 As shown, the lighting and signaling device 1 comprises a masking member 36 arranged to cover the periphery of the outer face 8 of the optical element 2. For example, the masking member 36 refers to a wall extending from the housing 6, facing the outer face 8 of the optical element 2 and covering at least the periphery of the optical element 2. Therefore, the wall can have a specific profile, cutting the profile of the signaling beam emitted by the lighting and signaling device 1 according to the present invention, thereby ensuring a discernible visual recognition of the vehicle.

[0096] Also in this case, it should be noted that the presence of the masking member 36 at the periphery of the optical element 2 does not cause incompatibilities with the various configurations mentioned above with reference to the first embodiment.

[0097] As a reminder, the invention relates to a lighting and signalling device comprising a lighting module and a controllable liquid crystal screen adapted to assume different diffusion states and arranged to straddle the emission direction of the light beam emitted by the lighting module, the different diffusion states of the controllable liquid crystal screen being defined by an appropriate power supply according to the need to emit an illumination beam (which must not be deflected or only slightly deflected at the output of the lighting module) or a signalling beam. The invention is therefore particularly advantageous because it makes it possible to use the same lighting surface for each of the lighting functions and the signalling functions performed by the lighting and signalling device, without interfering with the prescribed projection of the illumination beam.

[0098] However, the present invention is not limited to the devices and configurations described and illustrated herein, but also extends to any equivalent devices and configurations and any technically feasible combination of such devices.

Claims

1. A lighting and signalling device (1), comprising: at least one lighting module (4), the at least one lighting module being adapted to generate an illumination beam (A) along a longitudinal optical axis; and an optical element (2), through which the illumination beam (A) is projected, characterized in that the illumination and signaling device (1) comprises a controllable liquid crystal screen (18) pressed against the optical element (2), the controllable liquid crystal screen (18) being suitable for presenting different diffusion states, the diffusion states at least comprising: an illumination beam (A) projection state, in which the controllable liquid crystal screen (18) is transparent; and a signaling beam emission state, in which the controllable liquid crystal screen (18) is at least partially diffuse.

2. A lighting and signalling device (1) according to the preceding claim, wherein: The controllable liquid crystal screen (18) comprises two transparent walls (20, 22), a polymer matrix (24) extending between the two transparent walls (20, 22) and interspersed with liquid crystals, and two electrodes respectively associated with one of the transparent walls.

3. The lighting and signaling device (1) as claimed in any one of the preceding claims comprises a control member (28) for controlling the controllable liquid crystal screen (18), wherein the control member is configured to supply power to the controllable liquid crystal screen (18) so that the controllable liquid crystal screen (18) changes from a projection state to a signaling beam emission state, or from a signaling beam emission state to a projection state, according to a change in power supply.

4. The lighting and signaling device (1) according to any of the preceding claims, comprising a main light source which is part of the lighting module (4) and an additional light source (12) which is mounted facing the optical element (2).

5. Lighting and signalling device (1) according to the preceding claim, wherein: The optical element (2) has an inner surface (10) in contact with the controllable liquid crystal screen (18), an opposite outer surface (8), and a peripheral edge connecting the inner surface (10) to the outer surface (8), and the additional light source (12) is installed facing the peripheral edge of the optical element (2).

6. A lighting and signalling device (1) according to any one of the preceding claims, wherein: The controllable liquid crystal screen (18) comprises a first portion (30) and a second portion (32) extending around the periphery of the first portion (30), the diffusion state of one of the portions of the controllable liquid crystal screen (18) being independent of the diffusion state of another of the portions.

7. Lighting and signalling device (1) according to the preceding claim in combination with claim 3, wherein: The first portion (30) is powered by the control member (28) independently of the second portion (32).

8. A lighting and signalling device (1) according to any one of claims 6 and 7, comprising a light diffusing element (34) arranged facing the second part (32) of the controllable liquid crystal screen (18).

9. A lighting and signalling device (1) according to any one of claims 6 to 8, comprising a masking member (36) arranged to cover the periphery of the outer face (8) of the optical element (2).

10. A motor vehicle equipped with at least one lighting and signalling device (1) as claimed in any one of the preceding claims.

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