A light-emitting device having a light-emitting module with a flexible guide sheet and disposed in front of the lighting module

Abstract

The invention relates to a lighting device (300) for a motor vehicle or the like, the lighting device (300) comprising at least one lighting module (301.1; 301.2) suitable for projecting light rays to perform a lighting function, and a flexible guide sheet suitable for receiving light rays and reflecting the light rays in a direction substantially perpendicular to the surface of the flexible guide sheet, and at least one light injection element suitable for receiving light and distributing the light in the flexible guide sheet, and also comprising a lighting module (400; 500; 600) including at least one light source suitable for injecting light into the light injection element. The lighting module is arranged such that light rays from the lighting module pass through the flexible guide sheet, and the light source is activated when the lighting module is deactivated.

Description

Technical Field

[0001] The present invention relates to the field of lighting devices comprising one or more lighting modules, in particular for automotive vehicle headlamps. The invention applies, but is not limited to, the appearance of such headlamps, especially when the vehicle is driven during the day.

Summary of the Invention

[0002] Lighting devices such as headlamps generally have a plurality of lighting functions carried out by one or more modules. In particular, the following lighting functions are known: - A low beam (LB) type lighting function; - A high beam (HB) type lighting function that can be carried out by the same lighting module as for the LB function or by another module; - A daytime signal transmission function, also called daytime running lights (DRL), generally carried out by a lighting module separate from the LB / HB module; - A position light (PL) type signal transmission function that can be carried out by the lighting module executing the DRL function or by another lighting module.

[0003] The appearance of the lighting device depends on the respective arrangement, number and respective shape of the lighting modules and is called the "signature". This signature is particularly visible when all the modules of the lighting device are operating.

[0004] This signature can be perceived differently between night-time driving and daytime driving. This is because at night, the modules that execute lighting functions such as LB and HB are visible to an external observer. Thus, a complete signature is obtained.

[0005] However, during the day, these lighting functions generally do not operate, which results in one or more black areas in the signature of the light-emitting device. The signature of the light-emitting device is incomplete and different from the night signature for an observer outside the vehicle.

[0006] Therefore, it is necessary to harmonize the signature of the light-emitting device for motor vehicles between daytime driving and nighttime driving.

[0007] One of the known solutions is to use a liquid crystal film such as a PDLC (Polymer-Dispersed Liquid Crystal) film to cover the dark areas corresponding to the lighting functions.

[0008] However, this solution has the following disadvantages: - It is sensitive to temperature, especially negative temperature, and does not function below -20°C; - It is based on an organic pigment that is sensitive to humidity and light and must be absolutely isolated from the outside; - It is difficult to integrate into the light-emitting device, especially when the outer surface is not flat.

[0009] Therefore, it is necessary to harmonize the signature of the light-emitting device for motor vehicles between day and night, and to provide a robust, easily integrated and inexpensive solution.

[0010] The present invention aims to improve this situation.

[0011] For this purpose, a first aspect of the invention relates to a light-emitting device for a motor vehicle, comprising at least one lighting module adapted to project light rays to perform a lighting function, and further comprising a light-emitting module including: A flexible guide sheet adapted to receive light rays through at least one edge of the flexible guide sheet and to reflect light rays in a direction substantially perpendicular to the surface of the flexible guide sheet; At least one light injection element adapted to receive light and to distribute light in a flexible guide sheet; At least one light source adapted to put light into the at least one light injection element.

[0012] The flexible guide sheet is transparent, the light emitting module is arranged such that the flexible guide sheet passes light rays from the lighting module, and the light source is activated when the lighting module is deactivated.

[0013] The use of a light emitting module that is activated when the lighting module is deactivated makes it possible to harmonize the signature of the lighting device between daytime driving and nighttime driving. Furthermore, the light emitting module is of the flexible guide sheet type, is inexpensive, easy to manufacture, and easy to incorporate compared to prior art solutions. Finally, such a solution is not very sensitive to environmental conditions such as humidity and temperature.

[0014] According to an embodiment, the flexible guide sheet may be adapted to reflect light rays according to at least one pattern etched in the flexible guide sheet, and the light emitting area of the pattern may be arranged facing the optical projection surface of the lighting module.

[0015] By etching the flexible guide sheet in this way, it is easy to reproduce the signature of the lighting device regardless of the shape of the optical projection surface of the lighting module, which desirably has dark areas when it is inactive.

[0016] According to an embodiment, the at least one lighting module may be adapted to perform a low beam lighting function or a high beam lighting function.

[0017] These functions are typically deactivated during the day, and the modules that execute them are specifically adapted to create dark areas in the signature of the light-emitting device.

[0018] Furthermore, the lighting module may be adapted to execute a low beam lighting function and a high beam lighting function.

[0019] In this way, the same module may execute both functions, which limits the space required to execute these functions in the light-emitting device.

[0020] Alternatively, the light-emitting device may include a first lighting module adapted to execute a low beam lighting function and a second lighting module adapted to execute a high beam lighting function, and the light-emitting module is arranged such that the flexible guide sheet passes the light rays from the first lighting module or the second lighting module through it.

[0021] In this way, the light-emitting device may include two lighting modules, and the light-emitting module may be adapted to shield the dark area associated with at least one of these two lighting modules.

[0022] Furthermore, the light-emitting module may be arranged such that the flexible guide sheet passes the light rays from the first lighting module and the second lighting module through it.

[0023] Therefore, a light-emitting module having a single flexible guide sheet can cover both lighting modules. Specifically, since they are flexible, have a large surface area, and a thin thickness, the light-emitting module can be easily incorporated by being arranged opposite the two lighting modules without making the light-emitting device very bulky.

[0024] According to an embodiment, the light emitting module may comprise a single flexible guide sheet, a first pattern is etched in a first portion of the flexible guide sheet, a second pattern is etched in a second portion of the flexible guide sheet, the light emitting area of the first pattern may be arranged facing a first optical projection surface of the first lighting module, and the light emitting area of the second pattern may be arranged facing a second optical projection surface of the second lighting module.

[0025] In this way, the bulk and cost associated with the light emitting module are reduced, and a single injection element and source illuminate two light emitting areas facing two separate lighting modules. This embodiment is referred to as the second embodiment for the remainder of this specification.

[0026] According to another embodiment, the light emitting module may comprise a single flexible guide sheet, a first injection element, and a second injection element. The first injection element may be arranged to inject light into a first section of an edge of the flexible guide sheet, the second injection element may be arranged to inject light into a second section of an edge of the flexible guide sheet. A first portion of the flexible guide sheet arranged to face the first section of the edge is etched according to a first pattern, a second portion of the flexible guide sheet arranged to face the second section of the edge is etched according to a second pattern, the light emitting area of the first pattern may be arranged facing a first optical projection surface of the first lighting module, and the light emitting area of the second pattern may be arranged facing a second optical projection surface of the second lighting module.

[0027] This variation, referred to below as the third embodiment, advantageously allows selective control of the illumination of the first and second light emitting areas. Thus, it is possible to illuminate only one of the two light emitting areas, particularly when only one of the lighting modules is deactivated.

[0028] Alternatively, the light-emitting device may include a first light-emitting module and a second light-emitting module. The first light-emitting module includes a first flexible guide sheet, a first injection element, and a first light source. The second light-emitting module includes a second flexible guide sheet, a second injection element, and a second light source. The first light-emitting module may be arranged such that the first flexible guide sheet allows the light rays from the first lighting module to pass through it. The second light-emitting module may be arranged such that the second flexible guide sheet allows the light rays from the second lighting module to pass through it.

[0029] Accordingly, one light-emitting module may be provided for each lighting module, which facilitates the positioning of the light-emitting module and thus facilitates its incorporation into the light-emitting device. In the following description, this embodiment is referred to as the first embodiment.

[0030] According to an embodiment, the light-emitting module may be arranged within the lens of the optical system of the lighting module.

[0031] In this way, the light-emitting module is mechanically protected while facilitating its positioning and thus facilitating its incorporation into the light-emitting device.

[0032] According to another embodiment of the invention, the light-emitting module may be arranged on the outer lens of the light-emitting device.

[0033] Light-emitting devices such as headlamps are subject to very large space constraints. In this case, by arranging the light-emitting module outside the light-emitting device, the required space is limited.

[0034] According to an embodiment, the lighting device may further include a signal transmission module adapted to perform a signal transmission function.

[0035] In this way, the lighting device may perform a lighting function and a signal transmission function and may have a complex signature.

[0036] Furthermore, the signal transmission module may be adapted to perform a daytime running light function or a position light function.

[0037] These functions are usually necessary and may therefore be integrated with the lighting function in the light emitting device.

[0038] In addition, the signal transmission module may be adapted to perform a daytime running light function and a position light function.

[0039] In this way, the same module is adapted to perform multiple signal transmission functions. In particular, such functions may vary only by the luminous intensity emitted, and thus only by the power supply level applied to the light source of the signal transmission module.

[0040] According to an embodiment, the light emitting device may further include a control unit adapted to activate the at least one light source when the lighting module is deactivated.

[0041] In this way, the control unit may be incorporated into the light emitting device, making it easier to operate the light emitting module.

[0042] Furthermore, the control unit may be adapted to activate or deactivate the lighting module in response to a control signal.

[0043] In this way, the control unit may control both the lighting module and the light emitting module, making it easier to harmonize the signatures between daytime driving conditions and nighttime driving conditions.

[0044] In addition, the control unit may be adapted to operate the signal transmission module.

[0045] Therefore, the same control unit may operate all the modules of the lighting device. In this way, centralized management of the signal transmission function and the lighting function becomes possible.

[0046] Furthermore, the control unit may be adapted to activate a signal transmission module adapted to execute a daytime running light function, and in the activation of the daytime running light function, the control unit may be configured to activate the at least one light source of the light emitting module.

[0047] Specifically, since this signal transmission function is activated during the day, when the lighting function is deactivated, the light emitting module is activated. This makes it easier to harmonize the signature of the light emitting device.

[0048] According to an embodiment, each flexible guide sheet may comprise a film including a microstructure, and each pattern may be etched by ultraviolet printing of the microstructure of the film.

[0049] These microstructures make it possible to maintain a high level of transparency of the flexible guide sheet while projecting light onto the light emitting area when the light source is activated.

[0050] Furthermore, for each flexible guide sheet, the surface density of the microstructure may decrease with the distance from the edge of the guide sheet where light is incident.

[0051] In this way, the homogeneity of the pattern projected by the flexible guide sheet is improved.

Brief Description of the Drawings

[0052] Other features and advantages of the invention will become apparent upon consideration of the following detailed description and the accompanying drawings, in which:

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

DETAILED DESCRIPTION OF THE INVENTION

[0053] The description focuses on features that differentiate the interior device and the light-emitting module from those known in the prior art.

[0054] FIG. 1 shows a light-emitting module 100 of a light-emitting device for a motor vehicle according to the invention.

[0055] The light-emitting module 100 comprises a flexible guide sheet 110 adapted to receive light rays via an edge 114 and, thus, to reflect the light rays in a direction Z substantially perpendicular to the surface of the flexible guide sheet extending in the plane X-Y of FIG. 1.

[0056] The guide sheet is understood to mean an optical guide element in which one of its dimensions in space is much smaller than the other two dimensions, for example smaller than a single-digit unit. As shown in FIG. 1, in this case, it is a flexible guide sheet, and the thickness of the flexible guide sheet along the Z-axis is at least two orders of magnitude smaller than its dimension in the plane X-Y in which the flexible guide sheet 110 extends.

[0057] The flexible guide sheet 110 may include, in its core, a flexible film 111 including at least one edge 114, be adapted to guide light rays in the overall direction X, and include a set of microstructures 113 adapted to reflect the light rays guided in the flexible film 111 outside the flexible guide sheet 110, particularly in one or more directions substantially along the axis Z.

[0058] The flexible film 111 may be a base film made of polycarbonate (PC), polymethyl methacrylate (PMMA), thermoplastic polyurethane (TUP), or polyethylene terephthalate (PET). The flexible film 111 may have a thickness of 12 to 1000 micrometers and may have a thickness that is a dimension along the axis Z. More specifically, the thickness of the flexible film 111 may be 50 to 1000 micrometers, for example 200 to 500 micrometers. Alternatively, it is a flexible guide sheet 110 having a thickness of 200 to 1000 micrometers.

[0059] Combined with the small thickness as described above, the above materials make it possible to obtain the flexible film 111. Other materials may also be considered for the composition of the flexible film 111. However, according to the invention, it is preferable to provide a deformable transparent material.

[0060] The thin coating of the microstructures 113 may be applied to one of the surfaces of the flexible film 111 or may be integrated into the flexible film 111. The microstructure coating 113 may particularly have a thickness along the axis Z of less than 20 micrometers.

[0061] These microstructures 113 may generally take the form of irregularities, and the light rays are reflected in a direction substantially along the axis Z by the irregularities. These microstructures 113 may be adapted so that the light rays emerging from the flexible film 111 form a pattern. For this purpose, the microstructures 113 may be etched by ultraviolet printing according to a desired pattern.

[0062] The microstructure 113 is a structure having dimensions smaller than several micrometers or irregularities on a flexible film. Thus, the microstructures cover also nanometer structures. Such a size of the microstructure 113 enables ensuring high transparency of the flexible film 111. In particular, by using the microstructure 113, a transparency of the order of 97% can actually be obtained. Alternatively, the flexible guide sheet may be translucent or opaque.

[0063] Advantageously, the microstructure 113 may be distributed along the axis X such that the line density of the microstructure 113 is proportional to the distance from the edge 114 and the light rays injected by the injection element 120 through the edge 114 are received. In other words, the farther the microstructure 113 is from the edge 114, the more densely they are grouped. Such a distribution advantageously enables ensuring a homogeneous distribution along the axis X of the luminous intensity of the pattern emitted by the flexible guide sheet 110.

[0064] The flexible guide sheet 110 may further include one or two optional protective layers 112.1 and 112.2, which makes it possible to mechanically protect the flexible film 111. Furthermore, at least one of the protective layers 112.1 and 112.2 may include an anti-UV treatment, which makes it possible to protect the flexible film against ultraviolet rays when the microstructure 113 is etched. Without such UV protection, the pattern projected by the flexible guide sheet 110 is liable to deteriorate over time, especially when exposed to sunlight.

[0065] The flexible film 111 and the protective layers 112.1 and 112.2 are shown spaced apart in Figure 1 for purely illustrative purposes. However, it will be understood that the protective layers 112.1 and 112.2 may be attached to the flexible film, in particular by lamination.

[0066] Since the guide sheet 110 is flexible, it is not necessarily contained in a plane and may be curved depending on the position where it is disposed and the mechanical constraints applied thereto.

[0067] The light emitting module 100 shown in FIG. 1 also includes a light injection element 120, also referred to as a light bar, which is adapted to inject light in a direction perpendicular to its longitudinal direction, for example along the axis X when it is disposed in the manner shown in FIG. 1 since it extends longitudinally in the direction Y.

[0068] The light injection element 120 has a rectangular or square cross section in FIG. 1. However, the light injection element 120 may have a circular, oval, or polygonal cross section.

[0069] Thus, the light injection element 120 includes an output surface 122 extending in the longitudinal direction, and the output surface 122 is adapted to inject light in a direction substantially perpendicular to the output surface 122. The light injection element 120 further includes an input surface 121 adapted to receive light rays from the light source 130 at one end of the light injection element 120, and the light injection element 120 is adapted to guide the light longitudinally along the axis Y and distribute it across the output surface 122. The distribution of light by the output surface 122 will be more clearly understood from the description of FIG. 2.

[0070] There is no limitation on the light source 130. The light source 130 may be adapted to generate light in a wavelength range. Such a range may be centered on visible colors, for example to generate colored light such as blue, red or green. Alternatively, the light source 130 may emit light rays over the entire range of wavelengths visible to the human eye so as to generate white light. A very narrow wavelength range may be generated by a laser type light source 130.

[0071] The light source 130 may be adapted to generate light in at least two different wavelength ranges, for example corresponding to two different colors. It may be, for example, small-sized, have the advantages of low energy consumption and little heating, and be a light-emitting source of, for example, the LED type, which is adapted to generate light of two different colors and be controlled by a control element (not shown). In particular, it may be an RGB type diode adapted to generate red, green and blue light. Accordingly, the light-emitting module according to the first embodiment may include a flexible guide sheet 110, an injection element 120, and a light source 130 adapted to generate light in at least two different wavelength ranges.

[0072] The light source 130 may be controlled by a control element (not shown but described below).

[0073] Alternatively, the light source 130 is not disposed directly opposite the input surface 121 of the injection element 120, but the light-emitting module 100 further includes an optical fiber disposed between the source 130 and the injection element 120, which makes it possible to move the source 130 away from the assembly formed by the injection element 120 and the flexible guide sheet 110.

[0074] FIG. 2 shows the injection element 120 of the light-emitting module according to an embodiment of the invention.

[0075] The injection element 120 may include a plurality of injection guides 123 adapted to receive light from the source 130 via the input surface 121 and to guide the light to a longitudinal position at the output surface 122, and the longitudinal positions of the light guides are distinguished so as to distribute light to at least some longitudinal positions at the output surface 122.

[0076] Thereby, it becomes possible to make light incident at different longitudinal positions along the axis Y at the edge 114. Each longitudinal position at the edge 114 may correspond to a guideline of the flexible film 111 and is adapted to guide light along the axis X along such a guideline.

[0077] Thus, such a combination of the flexible guide sheet 110, the injection element 120, and the source 130 enables light to be projected in the direction Z according to a given pattern with good surface homogeneity through a flexible transparent or translucent surface.

[0078] In fact, such a light-emitting module can be made to emit a pattern having a light-emitting area with a luminance of 100 candela to 1000 candela per square meter with a light extraction efficiency ranging from 25% to 80%.

[0079] Details regarding the structure and arrangement of these elements 110, 120, and 130 are further described in the international patent application published under the number WO2011130715A2.

[0080] The light-emitting module of the vehicle lighting device according to the invention comprises the following: - A guide sheet, such as the flexible guide sheet 110 shown in FIG. 1, adapted such that the assembly reflects light according to at least one pattern; - At least one light injection element, such as the injection element 120 described with reference to FIGS. 1 and 2; and - At least one light source, such as the light source 130 described above with reference to FIG. 1, adapted to inject light into the at least one injection element.

[0081] The term "pattern" means any predetermined spatial distribution of the light emission intensity emitted by the light emitting module. In particular, here, two-dimensional or one-dimensional patterns are referred to. Thus, the pattern can include two-dimensional shapes or symbols obtained by the contrast between the light emission intensities at different positions in the plane X-Y of the flexible guide sheet 110. The pattern can also include several shapes or symbols. Alternatively, the pattern covers a predetermined or intentional spatial distribution of luminous intensity, such as a distribution that does not result in a general shape, such as a cloud of light emitting dots. In the context of the present invention, the pattern is formed by injecting light into the injection element, and the injection element is arranged relative to the flexible guide sheet so as to form a pattern in the flexible guide sheet. The flexible guide sheet is thus adapted to project light according to at least one pattern, and the pattern can correspond to at least one shape or symbol. Also, when the flexible guide sheet is combined with a plurality of injection elements, the flexible guide sheet can project light according to at least two patterns. The shape or symbol can be created by the contrast between the light emitting area where the light rays are emitted and the dark area where the light rays are not emitted.

[0082] Figure 3 shows a light emitting device 300 according to an embodiment of the invention.

[0083] As described above, the light emitting device 300 according to the invention comprises at least one light emitting module, the embodiments of which are described in Figures 4, 5 and 6 and referred to as 400, 500, 600 in Figure 3. As will become apparent, the light emitting device 300 may comprise a plurality of light emitting modules.

[0084] The light-emitting device 300 further comprises lighting modules 301.1; 301.2 adapted to project light rays towards the outside of the light-emitting device 300 so as to perform at least one lighting function. This lighting function can be, for example, a low beam (LB) function or a high beam (HB) function. Alternatively, the lighting modules 301.1; 301.2 can be controllable, for example by a control element 340, and be controlled to perform two different lighting functions such as the LB function and the HB function. There is no limitation to the technology related to the lighting module. The light source of the lighting modules 301.1; 301.2 is not particularly limited, and it can be a light-emitting element such as one or more LEDs or a light source including a plurality of light-emitting elements. The light source of the lighting module can be an array source including an array of DMD-type micromirrors, an array of LEDs, or any other arbitrary array source.

[0085] Optionally, the light-emitting device 300 may include one or more signal transmission modules 302.1; 302.2 and 302.3 adapted to project light rays towards the outside of the light-emitting device so as to perform a signal transmission function. The signal transmission module may be adapted to perform, for example, a position light PL function or a daytime running light DRL function. Further, the signal transmission module may be adapted to perform both the position light PL function and the daytime running light DRL function, and only the luminous intensity emitted by the signal transmission module is variable between the two functions. Such a change in luminous intensity may be obtained by activating / deactivating the light source of the signal transmission module, or by changing the duty cycle, or by supplying power to the light source by pulse width modulation.

[0086] The light-emitting device 300 for an automotive vehicle is preferably a headlamp for an automotive vehicle, for example a front headlamp for an automotive vehicle.

[0087] There is no limit to the number of lighting modules, light-emitting modules, and signal transmission modules provided in the light-emitting device 300, and there is also no limitation on the respective shapes and arrangements of them that constitute the signature of the light-emitting device 300. As described above, the light-emitting device according to the invention comprises the following: - At least one lighting module; - At least one light-emitting module as described above; - Optionally, at least one signal transmission module.

[0088] In a specific example shown in FIG. 3, the light-emitting device 300 comprises the following: - A first lighting module 301.1 and a second lighting module 301.2. For example, the first lighting module 301.1 may perform a low beam LB lighting function, while the second lighting module 301.2 may perform a high beam HB lighting function; - A first signal transmission module 302.1 in two upper and lower parts, a second signal transmission module 302.2 in two upper and lower parts, and a third signal transmission module 302.3 in two upper and lower parts. Each signal transmission module 302.1; 302.2 or 302.3 is adapted to project a light beam outwardly of the light-emitting device so as to perform a signal transmission function. Each signal transmission module may perform its own signal transmission function, or the signal transmission modules 302.1, 302.2, 302.3 may perform the same signal transmission function and thus may be controlled together, for example, by a control element 340; - Depending on the embodiment, a light-emitting module 400, 500, 600 or two light-emitting modules 400, 500, 600.

[0089] The control element 340 may centralize the control of all those modules, in other words, the lighting module, the light-emitting module, and the signal transmission module. The control element 340 may control the activation or deactivation of each module according to a control signal received by a central control module of an automotive vehicle, such as an electronic control unit (ECU).

[0090] The control element 340 may include a memory such as a random access memory (RAM), a read-only memory (ROM), or any other type of memory (such as flash, EEPROM, etc.), and a processor configured to communicate unidirectionally or bidirectionally with the memory via one or more buses or a wired connection. Alternatively, the memory may include a plurality of memories of the aforementioned types. Preferably, the memory is a non-volatile memory. The processor is adapted to execute instructions stored in the memory and control the modules of the light-emitting device 300 in response to control signals. Alternatively, the processor may be replaced by a microcontroller designed and configured to execute control of the modules in response to received control signals.

[0091] Alternatively, each module includes a dedicated control element.

[0092] FIG. 4 shows a light-emitting module 400 of a light-emitting device according to a first embodiment of the invention.

[0093] The light-emitting module 400 includes a flexible guide sheet 410, an injection element 420, and a light source 430 similar to the flexible guide sheet 110, the injection element 120, and the light source 130 described above.

[0094] The flexible guide sheet 410 is etched according to a pattern including a light-emitting area 450 adapted to reflect the light rays injected by the injection element 420 after activation of the light source 430.

[0095] The light-emitting area 450 is arranged facing the optical projection surface of the illumination module. Also, the light-emitting area 450 may be shaped to overlap the optical projection surface of the illumination module. Accordingly, the light-emitting area 450 may have the same shape as the projection of the optical projection surface of the illumination module in the plane of the flexible guide sheet.

[0096] This makes it possible to illuminate the light-emitting area 450 by operating the light source 430 when the lighting module in which the light-emitting module 400 is arranged is deactivated. Therefore, an outside observer does not see a dark area in the area of the lighting module when it is deactivated, as is generally seen during the day. Thus, the invention makes it possible to homogenize the signature of a light-emitting device including the light-emitting module 400 arranged on the lighting module.

[0097] The light-emitting module 400 can be used, for example, in the example of FIG. 3 and is arranged facing the lighting module 301.1 or the lighting module 301.2. Alternatively, the light-emitting device 300 comprises a first light-emitting module identical to the light-emitting module 400 arranged facing the first lighting module 301.1 and a second light-emitting module identical to the light-emitting module 400 arranged facing the second lighting module 301.2.

[0098] Thus, a plurality of light-emitting modules 400 may advantageously be used in a light-emitting device comprising a plurality of lighting modules. When the lighting modules have optical surfaces of different shapes, the light-emitting area 450 of the light-emitting module 400 varies so as to be identical to each of the optical surfaces of the lighting modules that they cover. This makes it possible to homogenize a complex signature between day and night.

[0099] Advantageously, the light source 430 is controlled by the control element 340 described above. Also, the control element 340 may control the lighting module on the opposite side where the light-emitting module 400 is arranged. Thus, the control element 340 is adapted to activate the light source 430 when it deactivates the lighting module.

[0100] In the example of FIG. 3, when the first lighting module 301.1 is deactivated, the control element 340 may activate the first light emitting module 400 disposed facing the first lighting module 301.1, and when the second lighting module 301.1 is deactivated, the control element 340 may activate the second light emitting module 400 disposed facing the second lighting module 301.2.

[0101] Alternatively, referring to FIGS. 5 and 6, two embodiments are shown in which a single light emitting module 500 or 600 may be disposed facing at least two lighting modules of the lighting device.

[0102] FIG. 5 shows the light emitting module 500 of the lighting device according to the second embodiment of the invention.

[0103] According to the second embodiment, the light emitting module 500 includes a flexible guide sheet 510, an injection element 520, and a light source 530, which are similar to the flexible guide sheet 110, the injection element 120, and the light source 130 described above.

[0104] The flexible guide sheet 510 is etched according to a pattern including a first light emitting area 550.1 and a second light emitting area 550.2, and is adapted to reflect the light rays injected by the injection element 520 following the activation of the light source 530.

[0105] The first light emitting area 550.1 is disposed facing the first optical projection surface of the first lighting module, and the second light emitting area 550.2 is disposed facing the second optical projection surface of the second lighting module. Also, the first and second light emitting areas 550.1 and 550.2 may be shaped to overlap the optical projection surfaces of the first and second lighting modules. Accordingly, the first and second light emitting areas 550.1 and 550.2 may have the same shape as the projection of the optical projection surface of the lighting module in the plane of the flexible guide sheet 510.

[0106] Thus, when the first lighting module and / or the second lighting module in which the light-emitting module 500 is disposed is deactivated, by activating the source 530, it becomes possible to illuminate the light-emitting areas 550.1 and 550.2. Therefore, as is generally seen during the day, when at least one of the lighting modules is deactivated, an external observer will not see a dark area in the area of the lighting module. Thus, the invention makes it possible to homogenize the signature of a lighting device including the light-emitting module 500 disposed in a plurality of lighting modules using a single flexible guide sheet 510, a single injection element 520, and a single light source 530. This reduces the bulk and cost.

[0107] The light-emitting module 500 may be used, for example, in the example of FIG. 3 and is disposed facing the lighting modules 301.1 and 301.2.

[0108] In this way, a single light-emitting module 500 may advantageously be used in a lighting device including a plurality of lighting modules. When the lighting modules have optical surfaces of different shapes, the light-emitting areas 550.1 and 550.2 have different shapes so as to be the same as the respective optical surfaces of the lighting modules they cover. This makes it possible to homogenize a complex signature between day and night.

[0109] Advantageously, the light source 530 is controlled by the control element 340 described above. Also, the control element 340 may control the lighting module in which the light-emitting module 500 is disposed on the opposite side. In this way, the control element 340 is adapted to activate the light source 530 when it deactivates at least one of the lighting modules of the lighting device.

[0110] In the example of FIG. 3, the control element 340 may activate the light emitting module 500 disposed facing the first lighting module 301.1 and the second lighting module 301.2 when the first lighting module 301.1 is deactivated, when the second lighting module 301.2 is deactivated, or when both the first and second lighting modules 301.1 and 301.2 are deactivated.

[0111] FIG. 6 shows the light emitting module 600 of the lighting device according to the third embodiment of the invention.

[0112] According to the third embodiment, the light emitting module 600 includes a flexible guide sheet 610, a first injection element 620.1, a second injection element 620.2, a first light source 630.1, and a second light source 630.2, which are similar to the flexible guide sheet 110, the injection element 120, and the light source 130 described above.

[0113] The flexible guide sheet 610 is etched according to a pattern including a first light emitting area 650.1 located in a first portion of the flexible guide sheet 610 and a second light emitting area 650.2 located in a second portion of the flexible guide sheet 610. Alternatively, it is conceivable that a first pattern is etched in the first portion of the flexible guide sheet 610 including the first light emitting area 650.1, and a second pattern is etched in the second portion of the flexible guide sheet 610 including the second light emitting area 650.2.

[0114] The first light source 630.1 is adapted to inject light into the first injection element 620.1, and the injection element 620.1 itself is adapted to inject or distribute light into the first portion of the flexible guide sheet so as to illuminate the first light emitting area 650.1. For this purpose, the first injection element 620.1 is disposed facing a first section of the edge 114 of the flexible guide sheet 610.

[0115] The second light source 630.2 is adapted to inject light into the second injection element 620.2, which in turn is adapted to inject or distribute light into a second portion of the flexible guide sheet 610 so as to illuminate a second light emitting area 650.2. For this purpose, the second injection element 620.2 is arranged facing a second section of the edge of the flexible guide sheet 610 that is different from the first section.

[0116] The first light emitting area 650.1 is arranged facing the first optical projection surface of the first illumination module, and the second light emitting area 650.2 is arranged facing the second optical projection surface of the second illumination module. Also, the first and second light emitting areas 650.1 and 650.2 may be shaped to overlap the optical projection surfaces of the first and second illumination modules. Accordingly, the first and second light emitting areas 650.1 and 650.2 may have the same shape as the projection of the optical projection surface of the illumination module in the plane of the flexible guide sheet 610.

[0117] This enables the light emitting areas 650.1 and 650.2 to be illuminated by selective activation of the sources 630.1 and 630.2. When the first illumination module is deactivated, the first light source 630.1 can be activated. When the second illumination module is deactivated, the second light source 630.2 can be activated. Thus, the sources 630.1 and 630.2 may be controlled separately, for example by the control element 340.

[0118] Alternatively, the control element 340 can activate the sources 630.1 and 630.2 simultaneously, and when at least one of the first and second illumination modules is deactivated, the first and second light emitting areas 650.1 and 650.2 are illuminated in this way.

[0119] Therefore, an external observer will generally not see a dark area in the area of the lighting module when at least one of the lighting modules is deactivated, as is generally the case during the day. Thus, the invention makes it possible to homogenize the signature of a lighting device including a light emitting module 600 arranged in a plurality of lighting modules using a single flexible guide sheet 610 by selectively lighting the first and second light emitting areas 650.1 and 650.2.

[0120] The light emitting module 600 may be used, for example, in the example of FIG. 3 and is arranged facing the lighting modules 301.1 and 301.2.

[0121] Thus, a single light emitting module 600 may advantageously be used in a lighting device comprising a plurality of lighting modules. If the lighting modules have different shaped optical projection surfaces, the light emitting areas 650.1 and 650.2 have different shapes so as to be identical to the respective optical surfaces of the lighting modules they cover. This makes it possible to homogenize a complex signature between day and night.

[0122] Advantageously, the light sources 630.1 and 630.2 are controlled by the control element 340 described above. Also, the control element 340 may control the lighting module on the opposite side where the light emitting module 600 is arranged. Thus, the control element 340 is adapted to selectively activate the light sources 630.1 and 630.2 when it deactivates at least one of the lighting modules of the lighting device.

[0123] In the example of FIG. 3, the control element 340 may illuminate the first light emitting area 650.1 arranged facing the first lighting module 301.1 when the first lighting module 301.1 is deactivated, and may illuminate the second light emitting area 650.2 arranged facing the second lighting module 301.2 when the second lighting module 301.2 is deactivated.

[0124] In the above-described embodiment, the light-emitting area may be controlled in response to the activation of one of the signal transmission modules. The control element 340 may control not only the light-emitting module and the lighting module, but also one or more signal transmission modules, as shown in FIG. 3. In particular, the control element 340 may advantageously activate the light sources of the light-emitting modules 400, 500, or 600 when the daytime running light DRL function is activated in at least one of the signal transmission modules responsible for this signal transmission function. Since this function is activated during the day, it is thus ensured that the light sources of the light-emitting modules are activated during the day, which makes it possible to homogenize the signature of the lighting device 300 between the daytime driving and nighttime driving situations.

[0125] The light-emitting area is a portion of a flexible guide sheet pattern adapted to reflect light rays guided to the flexible guide sheet to the outside of the flexible guide sheet. The luminous intensity within the light-emitting area can vary. Thus, the light-emitting area and the dark area can be distinguished by a pattern. Advantageously, according to the invention, the light-emitting area is arranged facing the optical surface of the lighting module and may have the same shape as these optical surfaces.

[0126] The present invention is not limited to the embodiments described above by way of example, but extends to other variations.

Claims

1. A lighting device (300) for a motor vehicle, comprising at least one lighting module (301.1; 301.2) adapted to project light rays so as to perform a lighting function, and further comprising a light emitting module (400; 500; 600), the light emitting module (400; 500; 600) comprising: - a flexible guide sheet (110; 410; 510; 610) adapted to receive light rays via at least one edge (114) of the flexible guide sheet and to reflect the light rays in a direction substantially perpendicular to the surface of the flexible guide sheet; - at least one light injection element (120; 420; 520; 620.1; 620.2) adapted to receive light and to distribute the light in the flexible guide sheet; - at least one light source (130; 430; 530; 630.1; 630.2) adapted to inject light into the at least one light injection element; wherein: - the flexible guide sheet is transparent, the light emitting module is arranged such that the flexible guide sheet allows the light rays from the lighting module to pass through it, and the light source is activated when the lighting module is deactivated. A lighting device (300).

2. The flexible guide sheet is adapted to reflect the light rays based on at least one pattern etched in the flexible guide sheet (110; 410; 510; 610), and the light emitting area (450; 550.1; 550.2; 650.1; 650.2) of the pattern is arranged facing the optical projection surface of the lighting module (301.1; 301.2). The lighting device according to claim 1.

3. The at least one lighting module is adapted to perform a low beam lighting function or a high beam lighting function. The lighting device according to claim 1 or 2.

4. The lighting module (301.1; 301.2) is adapted to perform a low beam lighting function and a high beam lighting function. The lighting device according to claim 3.

5. A first lighting module (301.1) adapted to execute a low beam lighting function and a second lighting module (301.2) adapted to execute a high beam lighting function, wherein the light emitting module (400; 500; 600) is arranged such that the flexible guide sheet passes the light rays from the first lighting module or the second lighting module, the light emitting device according to claim 3.

6. The light emitting module, wherein the flexible guide sheet (110; 410; 510; 610) is arranged to pass the light rays from the first lighting module (301.1) and the second lighting module (301.2), the light emitting device according to claim 5.

7. The light emitting module (500) comprises a single flexible guide sheet (510), a first pattern is etched on a first portion of the flexible guide sheet, a second pattern is etched on a second portion of the flexible guide sheet, and a light emitting area (550.1) of the first pattern is arranged facing a first optical projection surface of the first lighting module (301.1), and a light emitting area (550.2) of the second pattern is arranged facing a second optical projection surface of the second lighting module (301.2), the light emitting device according to claim 6.

8. The light emitting module (600) comprises a single flexible guide sheet, a first injection element (620.1), and a second injection element (620.2), the first injection element is arranged to inject light into a first section of the edge of the flexible guide sheet (610), the second injection element is arranged to inject light into a second section of the edge of the flexible guide sheet, a first portion of the flexible guide sheet located facing the first section of the edge is etched based on a first pattern, a second portion of the flexible guide sheet located facing the second section of the edge is etched based on a second pattern, a light emitting area (650.1) of the first pattern is arranged facing a first optical projection surface of the first lighting module (301.1), and a light emitting area (650.2) of the second pattern is arranged facing a second optical projection surface of the second lighting module (301.2), the light emitting device according to claim 6.

9. A light-emitting device comprising a first light-emitting module (301.1) and a second light-emitting module (301.2), wherein the first light-emitting module comprises a first flexible guide sheet (410), a first injection element (420) and a first light source (430), the second light-emitting module comprises a second flexible guide sheet, a second injection element and a second light source, the first light-emitting module is arranged such that the first flexible guide sheet allows the light rays from the first lighting module to pass therethrough, and the second light-emitting module is arranged such that the second flexible guide sheet allows the light rays from the second lighting module to pass therethrough, according to claim 5.

10. The light-emitting device according to one of claims 1 to 9, wherein the light-emitting module (400; 500; 600) is arranged within a lens of an optical system of the lighting module (301.1; 301.2).

11. The light-emitting device according to one of claims 1 to 9, wherein the light-emitting module (400; 500; 600) is arranged on an outer lens of the light-emitting device (300).

12. The light-emitting device according to one of claims 1 to 11, further comprising a signal transmission module (302.1; 302.2; 302.3) adapted to perform a signal transmission function.

13. The light-emitting device according to claim 12, wherein the signal transmission module (302.1; 302.2; 302.3) is adapted to perform a daytime running light function or a position light function.

14. The light-emitting device according to claim 13, wherein the signal transmission module (302.1; 302.2; 302.3) is adapted to perform a daytime running light function and a position light function.

15. The light-emitting device according to one of claims 1 to 14, further comprising a control unit (340) adapted to activate at least one light source (430; 530; 630) when the lighting module (301.1; 301.2) is deactivated.

16. The light-emitting device according to claim 15, wherein the control unit (340) is also adapted to activate and deactivate the lighting module (301.1; 301.2) in response to a control signal.

17. The light emitting device according to claim 15 or 16 and claim 13 or 14, wherein the control unit (340) is also adapted to operate the signal transmission module (302.1; 302.2; 302.3).

18. The control unit (340) is adapted to operate the signal transmission module (302.1; 302.2; 302.3) adapted to execute a daytime running light function, and when the daytime running light function is activated, the control unit is configured to activate the at least one light source (430; 530; 630). The light emitting device according to claim 17.

19. Each flexible guide sheet (110; 410; 510; 610) comprises a film (111) including a microstructure (113), and each pattern is etched by ultraviolet printing of the microstructure of the film. The light emitting device according to one of claims 1 to 18.

20. For each flexible guide sheet (110; 410; 510; 610), the surface density of the microstructure (113) decreases with the distance from the edge of the guide sheet where the light is incident. The light emitting device according to claim 19.

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