FR3065055A1 - LUMINOUS DEVICE FOR A VEHICLE COMPRISING A FLEXIBLE OLED ASSOCIATED WITH ELECTROMECHANICAL MEANS FOR DEFORMATION - Google Patents

Abstract

The present invention relates to a light device for a motor vehicle comprising at least one surface light source constituted by an organic light-emitting diode (11); characterized in that said organic electroluminescent diode (11) is of flexible type (FOLED) and in that said device further comprises electromechanical means (13) adapted to cooperate with at least a portion (11B) of said FOLED (11) to cause its deformation. The invention also relates to an optical signaling unit comprising at least one such light device.

Description

Holder (s): PEUGEOT CITROEN AUTOMOBILES SA Société anonyme.

Extension request (s)

Agent (s): PEUGEOT CITROEN AUTOMOBILES SA Public limited company.

LIGHT DEVICE FOR VEHICLE COMPRISING A FLEXIBLE OLED ASSOCIATED WITH ELECTROMECHANICAL DEFORMATION MEANS.

FR 3 065 055 - A1 (6 /) The present invention relates to a light device for a motor vehicle comprising at least one surface light source constituted by an organic light-emitting diode (11);

characterized in that said organic light-emitting diode (11) is of the flexible type (FOLED) and in that said device also comprises electromechanical means (13) capable of cooperating with at least one portion (11 B) of said FOLED (11 ) to cause its deformation.

The invention also relates to an optical signaling unit comprising at least one such light device.

Title of invention

Vehicle lighting device comprising a flexible OLED associated with electromechanical deformation means

Field of the invention

The present invention relates generally to the field of light signaling devices for motor vehicles.

Invention background

The signaling lights (position lights, stop lights, direction indicators, reversing lights, rear fog lights and daytime running lights) are intended to emit light by respecting regulatory photometric grids which impose compliance with ranges of specific light intensity for each of the points of these grids.

In particular, these signaling lights must comply with angles of geometric visibility which determine the area of the minimum solid angle in which the apparent surface of the light must be visible (ECE Regulation 48 2.13). This area is determined by the segments of a sphere whose center coincides with the reference center of the fire and whose equator is parallel to the ground. These segments are determined from the optical axis of the light: the horizontal angles correspond to longitude and the vertical angles to latitude. Within these angles of geometric visibility, there must be no obstacle to the propagation of light from any point on the apparent surface of the fire observed from infinity. This regulation is particularly demanding concerning the horizontal angles which the position lights and direction indicators must respect, namely 45 ° on the internal side and 80 ° on the external side.

For reasons of reduced electrical energy consumption, increased lifespan and freedom of style, it is now common to use, as an alternative to conventional incandescent bulbs, laser or light emitting diodes (the latter being more commonly known by the acronym "LEDs").

. It is thus known, in particular from French patent application FR 3 014 787, to associate a plurality of such diodes with a flat type light guide (more commonly known under the English name "fiat guide") housed at inside the housing and able to transfer the light rays which feed its entry surface to an exit front face located opposite said cover glass.

In order to satisfy the regulatory photometric grid, such a light guide must therefore be provided on its front face with optical elements capable of spreading the relatively directive light fluxes emitted by these diodes horizontally and vertically.

Despite everything, respecting the minimum angles of geometric visibility for this type of signaling light remains particularly difficult to obtain with point sources such as LEDs, in particular in the horizontal plane.

Recently, it has also been known to use so-called surface light sources, that is to say sources whose effective light-emitting surface has dimensions much greater than the thickness of these sources.

In particular, recent years have seen the emergence of organic light-emitting diodes (OLEDs) which make it possible to carry out certain signaling functions, such as for example the position light (or lanterns) function, while satisfying regulatory viewing angles while offering great freedom of style for car manufacturers.

American patent application US 2014/0056020 A1 thus discloses a light device for a motor vehicle comprising several independent surface light sources of the OLED type arranged in a circular manner.

Such a light device thus makes it possible to ensure certain signaling functions such as for example the position light function by generating a homogeneous light distribution less dazzling than that produced by devices based on LEDs, but which remains frozen whatever the circumstances. .

Subject and summary of the invention

The present invention aims to propose a light device based on surface sources having an evolving light distribution.

To this end, it proposes a light device for a motor vehicle comprising at least one surface light source constituted by an organic light-emitting diode;

characterized in that said organic light-emitting diode is of flexible type (FOLED) and in that said device further comprises electromechanical means able to cooperate with at least a portion of said FOLED to cause its deformation.

The light device according to the invention allows, thanks to the cooperation between the FOLED and the electromechanical means, to deform this FOLED in order to cause a modification of its light distribution.

This device thus offers the possibility of ensuring an evolving light distribution according to circumstances such as for example a change in the driving context and / or the occurrence of certain predetermined events.

According to preferred characteristics of the light device according to the invention, taken alone or in combination:

- A first edge of said FOLED is fixed while said electromechanical means comprise a first actuator comprising a piston mounted movably to slide in a jacket and whose free projecting end of said jacket is coupled to a second edge of said FOLED, opposite to said first fixed edge;

- The piston of said first actuator extends in a transverse direction to said first and second edges of the FOLED;

a third edge of said FOLED is fixed while said electromechanical means further comprises a second actuator comprising a piston mounted movably to slide in a jacket and whose free projecting end of said jacket is coupled to a fourth edge of said FOLED, opposite said third fixed edge;

- The piston of said second actuator extends in a direction transverse to said third and fourth edges of the FOLED;

- A first edge of said FOLED is fixed while said electromechanical means comprise a first actuator comprising a rotary axis whose free end is rigidly linked to a second edge of said FOLED, opposite to said first fixed edge;

- Said rotary axis extends in a direction transverse to said first and second edges of the FOLED;

- Said electromechanical means are coupled to a control module configured to activate them at least partially during a change in the driving context and / or the occurrence of certain predetermined events; and or

- Said device further comprises at least one additional point light source such as a light emitting diode or laser.

The invention also aims in a second aspect, an optical signaling unit comprising at least one such light device.

Brief description of the drawings

The description of the invention will now be continued with the detailed description of several exemplary embodiments, given below by way of illustration but not limitation, with reference to the appended drawings, in which:

- Figure 1 is a schematic sectional view along a horizontal plane of an optical signaling unit comprising a light device according to a first embodiment of the invention and in which the FOLED occupies a flat configuration;

- Figure 2 shows a view similar to Figure 1 but on which the FOLED occupies a curved configuration;

- Figure 3 is a schematic view in vertical cross section of an optical signaling unit comprising a light device according to a variant of this first embodiment;

- Figure 4 is a schematic front view of an optical signaling unit comprising a light device according to a second embodiment of the invention and in which all of the FOLEDs occupy a plane configuration; and

- Figure 5 shows a view similar to Figure 4 but in which one of the FOLEDs occupies a twisted curved configuration.

Detailed description of several preferred embodiments

Figures 1 and 2 show an optical signaling unit 1 for a motor vehicle.

In the description which follows and by convention, the terms "lower", "upper", "longitudinal" "lateral" and "transverse" will be defined relative to the mounting position of such an optical unit on a vehicle.

The signaling optical unit 1 comprises a housing 2 having an exit opening for the light rays which is closed in leaktight manner by a transparent cover glass 3.

The optical unit 1 also includes a light device 10 housed in the cavity delimited by the housing 2 and the cover glass 3.

This light device 10 comprises a surface light source of rectangular shape 11 constituted by an organic light-emitting diode (OLED for "Organic Light Emitting Diode" in English).

The basic structure of such an organic light-emitting diode (OLED) consists of superposing several layers of organic material between two layers forming electrodes, one of which (generally the anode) is affixed to a substrate.

The organic thin layers typically comprise a conductive layer with holes (HTL for “Hole Transport Layer” in English) deposited on the anode composed of indium tin oxide (ITO), an emitting layer (EL for “Emission Layer” in English ) containing a dye and an electron conducting layer (ETL for “Electron Transport Layer” in English).

The operation of OLEDs is based on the principle of electroluminescence.

By applying an appropriate electrical voltage, electrons and holes are injected into the EL layer from the cathode and the anode. The electrons and holes drift towards each other and combine in this EL layer to form excitons whose disaggregation provides the excitation energy of the dye molecule causing its electroluminescence. The color of the light emitted depends on the energy difference between the excited state and the basic state and can therefore be modified using other dye molecules.

The charge transfer materials, the emission layer and the choice of electrodes are fundamental parameters that determine the performance and efficiency of the OLED.

The organic light-emitting diode 11 is more precisely of the flexible type (FOLED for “Flexible Organic Light Emitting Diode” in English): its organic layers resting on a flexible plastic substrate such as polyethylene terephthalate (PET), or even of metal or glass .

The FOLED 11 is advantageously arranged vertically inside the housing 2 so that its optical axis X is oriented in a substantially longitudinal direction.

In order to maximize the luminance perceived from outside the optical unit 1, the electrode located on the internal side of this FOLED 11 (ie: opposite the cover glass 3) is reflective so that the light rays emitted towards the interior of the housing 2 are reflected in the direction of the cover glass 3.

The FOLED 11 also comprises, at least at one of its edges, an electrical connection interface, not shown, and cooperating with complementary means provided on the housing 2 in order to ensure its electrical supply.

A first vertical lateral edge 11A of this FOLED is also rigidly fixed to the housing 2 by means of a support 12.

According to the invention, the light device 10 further comprises an electromechanical actuator 13 housed inside the housing 2 and connected to a continuous or stepping electric motor not shown.

This actuator 13 comprises a piston 14 movably mounted to slide in a jacket 15 rigidly fixed to this housing 2 and extending in a transverse direction to the vertical lateral edges 11A, 11B of the FOLED 11.

The free end of this piston 14 projecting from the jacket 15 is coupled to the vertical lateral edge 11B of this FOLED 11 located opposite the fixed edge 11A.

In the retracted position of the piston 14, the latter exerts no force on the vertical lateral edge 11B so that the FOLED 11 occupies its planar configuration (FIG. 1) where it exhibits, when lit, a spatially uniform luminance and angularly (ie orthotropic or lambertian).

Thus, for an observer located at the rear of the vehicle (for example the driver of a following vehicle), the visual perception of the brightness of the FOLED 11 will be identical whatever the angle of observation.

When the piston 14 is slidingly driven by the electric motor, it exerts a transverse force on the vertical lateral edge 11B so as to force the FOLED 11 to adopt a substantially parabolic curved profile causing a modification of its light distribution (FIG. 2) .

A guidance device, not shown, is advantageously provided to guide the OLED in its deformation in order to ensure in particular that it curves in the right direction.

In this case, the curvature of this FOLED 11, the convexity of which is turned towards the outside, results in a reduction in its apparent surface for an observer placed in the axis of the vehicle (for example the driver of a line-following vehicle right) and therefore an increase in its luminance, this increase also being more pronounced at the level of its central zone which therefore has a greater luminance than the two lateral zones.

In addition, the convex profile of the FOLED 11 makes it possible to increase the level of light intensity emitted laterally and received by an observer placed at a significant angle of incidence relative to the axis of the vehicle (for example the driver of a following vehicle in a tight turn).

On the other hand, the perceived luminance will be lower because the apparent surface of the FOLED 11 seen from the side is larger.

The displacement of the piston 14 of the actuator 13 (and therefore the passage of the FOLED 11 in its curved configuration or vice-versa) is managed by a control module not shown housed in the optical unit 1 or outside this last (this module can for example be integrated into the on-board computer of the vehicle and be in a purely software form or in a form combining a hardware part provided with integrated circuits with a software part).

This control module, coupled (directly or indirectly) to the electric motor, is configured to automatically trigger the translational movement of the piston 14 (and therefore the passage of the FOLED 11 in its curved configuration) when the driving context changes. (for example, a change in lighting or traffic conditions) and / or the occurrence of certain predetermined events (for example, emergency braking, detection of a danger, or even activation / deactivation of the central locking of the doors), animation in reception mode, messages in circulation mode, etc.

FIG. 3 represents a rear optical signaling unit 1 ′ housing a light device 10 ′ in accordance with an alternative embodiment of the invention of the embodiment described above.

In the following and in this figure 3, the same references have been kept for the elements identical to the first embodiment and a premium has been added for similar elements.

The light device 10 'is similar to the device 10 described above except that:

- That the horizontal upper edge 11C of the FOLED 11 is also rigidly fixed to the housing 2 by means of a support 12 '; and

- It further comprises a second electromechanical actuator 13 'housed inside the housing 2 and connected to a continuous or stepping electric motor not shown, this actuator 13' comprising a piston 14 'mounted movably to slide in a jacket 15 'rigidly fixed to this housing 2.

The piston 14 'extends in a transverse direction to the upper 11C and lower 11D horizontal edges of the FOLED 11, its free end projecting from the jacket 15' being coupled to the lower edge 11D situated opposite the fixed edge 11C.

In the retracted position of the pistons 14 and 14 ', the latter exert no force on the lateral 11B and lower 11D edges so that the FOLED 11 occupies its planar configuration (FIG. 3).

When one of the pistons 14, 14 'is slidably driven, it exerts a transverse or vertical force on a corresponding edge 11B, 11D so as to force the FOLED 11 to adopt a curved profile causing a modification of its light distribution.

The electric motors driving the displacement of the pistons 14, 14 'of the actuators 13 and 13' are coupled to a control module configured to automatically trigger the translational movement of one of these pistons 14, 14 'or both simultaneously during '' a change in the driving context and / or the occurrence of certain predetermined events, so as to make adopt different curved configurations to the FOLED 11.

Figures 4 and 5 show a rear optical signal unit 100 housing a light device 110 according to a second embodiment of the invention.

This light device 110 comprises a plurality of rectangular FOLEDs 111 (in this case, four) arranged vertically inside the housing 102 and arranged side by side.

The horizontal upper edges 111C of these FOLEDs 111 are rigidly fixed to the housing 102 by means of a respective support 112.

The device 110 also includes four actuators 113 housed inside the housing 102 and connected to electric motors not shown.

Each actuator 113 comprises a rotary axis 114 extending in a transverse direction to the upper 111C and lower 111D horizontal edges of a respective FOLED 111, and the free end of which is rigidly connected to the lower edge 111D situated opposite the edge fixed 111C.

The rotary axis 114 of each actuator 113 is capable of adopting a first position in which the lower edge 111D of the corresponding FOLED 111 extends parallel to the upper edge 111C so that this FOLED 111 occupies its planar configuration (FIG. 4) where when it is lit, it has a uniform luminance spatially and angularly.

When this axis 114 is rotated by the electric motor to which it is connected, it forces the lower edge 111D to do the same so as to force the corresponding FOLED 111 to adopt a twisted curved profile (FIG. 5).

The electric motors are coupled to a control module configured to automatically trigger the rotation of the axis 114 of one or more actuators 113 simultaneously during a change in the driving context and / or the occurrence of certain events predetermined, so as to make adopt different configurations to the light device 110.

Many other embodiments can of course be envisaged in the context of the invention.

The number of FOLEDs can thus vary and each of them can be associated with a different number of actuators of different types.

The latter may for example consist of a stack of plates or discs capable of being expanded or compressed by piezoelectric or electrostrictive effect depending on the materials used.

The actuators can also be based on other principles such as electromagnetism or the Joule effect.

The displacement of certain portions of the FOLED can also be prevented in certain directions in order to generate more complex deformations of the latter (for example wavy shapes) providing a distinctive visual signature.

The luminance values currently associated with FOLEDs (of the order of 2000 cd / m ² ) make the light device according to the invention particularly suitable for achieving the position light (or lantern) function.

It is also possible to integrate into the light device according to the invention additional point light sources (for example light-emitting diodes or laser) in order to ensure in combination with the FOLED (s) of other signaling functions such as for example the function STOP light or the direction change indicator function.

The optical unit housing the device according to the invention can also contain other devices capable of performing other lighting and / or signaling functions such as for example the direction change indicator light function, the light function fog light or the daytime running light function (DRL for “Daytime running Light” in English).

Claims (10)

1. Lighting device for a motor vehicle comprising at least one surface light source constituted by an organic light-emitting diode (11; 111); characterized in that said organic light-emitting diode (11; 111) is of the flexible type (FOLED) and in that said device also comprises electromechanical means (13, 13 '; 113) capable of cooperating with at least one portion (11B , 11D; 111D) of said FOLED (11; 111) to cause its deformation. 2. Light device according to claim 1, characterized in that a first edge (11A) of said FOLED (11) is fixed, and in that said electromechanical means comprise a first actuator (13) comprising a piston (14) mounted movable to slide in a jacket (15) and whose free projecting end of said jacket (15) is coupled to a second edge (11B) of said FOLED (11), opposite to said first fixed edge (11A). 3. Light device according to claim 2, characterized in that the piston (14) of said first actuator (13) extends in a transverse direction to said first and second edges (11A, 11B) of said FOLED (11). 4. Light device according to one of claims 2 or 3, characterized in that a third edge (11C) of said FOLED (11) is fixed, and in that said electromechanical means further comprises a second actuator (13 ' ) comprising a piston (14 ') movably mounted to slide in a jacket (15') and whose projecting free end of said jacket (15 ') is coupled to a fourth edge (11D) of said FOLED (11), opposite said third fixed edge (11C). 5. Light device according to claim 4, characterized in that the piston (14 ') of said second actuator (13') extends in a direction transverse to said third and fourth edges (11C, 11D) of said FOLED (11). 6. Light device according to claim 1, characterized in that a first edge (111C) of said FOLED (111) is fixed, and in that said electromechanical means comprise a first actuator (113) comprising a rotary axis (114) the free end of which is rigidly connected to a second edge (111D) of said FOLED (111), opposite to said first fixed edge (111C). 7. Light device according to claim 6, characterized in that said rotary axis (114) extends in a direction transverse to said first and second edges (111C, 111D) of said FOLED (111). 8. Lighting device according to one of claims 1 to 7, characterized in that said electromechanical means (13, 13 '; 113) are coupled to a control module configured to activate them at least partially during a change of context conduct and / or the occurrence of certain predetermined events. 9. Light device according to one of claims 1 to 8, characterized in that it further comprises at least one additional point light source such as a light emitting diode or laser. 10. Optical signaling unit for a motor vehicle, characterized in that it comprises at least one light device according to one of claims 1 to 9. 1/2