Lighting module comprising a plurality of flexible guide sheets

Abstract

The invention relates to a lighting module (300) comprising at least two flexible guide sheets (310.1; 310.2), each sheet being suitable for reflecting light rays according to an etched pattern. A first light injection element (320.1) is suitable for distributing light in the first sheet and a second light injection element (320.2) is suitable for distributing light in the second sheet. The first sheet and the second sheet are arranged next to each other in such a way that a second edge (350.1) of the first flexible guide sheet faces a second edge (350.2) of the second flexible guide sheet. A portion of the first sheet along the second edge and a portion of the second sheet along the second edge are folded toward the interior of the lighting module or are covered with a reflective material.

Description

[0001] Description

[0002] Title: Light module with multiple flexible guide sheets

[0003] The present invention relates to the field of light modules, in particular light guide light modules. The invention applies in particular, but not exclusively, to the display of light patterns.

[0004] It is now required to display light patterns in many devices, for information signaling purposes, for aesthetic personalization or to create ambiance.

[0005] To do this, it is known to use screens, such as LCD screens.

[0006] However, such technology is not only expensive but also sensitive to environmental conditions such as temperature, humidity or UV radiation.

[0007] What's more, it is preferable to have a flexible light module to facilitate its integration into any type of equipment.

[0008] There is therefore a need for a light module capable of creating animation, and which is robust, inexpensive and easy to integrate into any type of equipment.

[0009] The international patent application published under number WO2011130715A2 proposes a flexible guide sheet capable of returning the light injected by an injection bar from a light source, according to a given pattern.

[0010] However, the size of such a flexible guide sheet is limited by manufacturing constraints. Thus, obtaining large-sized light modules based on this technology requires the use of at least two flexible guide sheets placed next to each other.

[0011] However, this technology has the disadvantage that the edges of a flexible guide sheet into which the light is injected appear as luminous. Thus, if two flexible guide sheets are placed next to each other to create a larger light module, their junction appears as luminous, which introduces an undesired defect in the projected patterns. In particular, if a shape or symbol is projected from the two complementary patterns of the two guide sheets, a luminous band will degrade the visual appearance of such a shape or symbol.

[0012] The present invention improves the situation.

[0013] For this purpose, a first aspect relates to a light module comprising: a set of at least two flexible guide sheets, comprising a first flexible guide sheet and a second flexible guide sheet, each flexible guide sheet of the set being capable of receiving light rays via at least a first edge of said flexible guide sheet and of returning the light rays in a direction substantially normal to a surface of the flexible guide sheet according to at least one pattern engraved in said flexible guide sheet; at least one first light injection element capable of receiving light and distributing the light in the first flexible guide sheet and a second light injection element capable of receiving light and distributing the light in the second flexible guide sheet;at least one light source capable of injecting light into the first light injection element and into the second light injection element;

[0014] The first flexible guide sheet and the second flexible guide sheet are arranged next to each other such that a second edge of the first flexible guide sheet faces a second edge of the second flexible guide sheet. The first flexible guide sheet and the second flexible guide sheet delimit an outer half-space towards which the light rays are emitted in the direction substantially normal to the surface of the flexible guide sheets, and an inner half-space of the light module, complementary to the outer half-space. A portion of the first flexible guide sheet extending along the second edge and a portion of the second flexible guide sheet extending along the second edge are folded towards the inner half-space or are at least partially covered with a reflective material.Thus, it is possible to produce light modules with a large light-emitting surface, which makes it possible to produce complex and large patterns. The junction between two flexible guide sheets does not illuminate unintentionally due to the folding of the second edges of the flexible guide sheets towards the inside of the module, according to a first embodiment, or by means of a reflective material arranged on the junction, according to a second embodiment.

[0015] According to the first embodiment, the light module further comprises a support arranged in the interior half-space and capable of holding the assembly of at least two flexible guide sheets, the support comprising a cavity capable of receiving the folded part of the first flexible guide sheet and the folded part of the second flexible guide sheet.

[0016] This makes it easier to integrate a module into equipment, such as motor vehicle equipment.

[0017] According to the first embodiment, the portion of the first flexible guide sheet extending along the second edge and the portion of the second flexible guide sheet extending along the second edge are folded towards the inner half-space and the reflective material at least partially covers a surface of the folded portions facing the inner half-space.

[0018] It is thus made possible to improve the light output of the light module according to the first embodiment, since the light which reaches the surface oriented towards the inner half-space is returned into the flexible guide sheet to be emitted according to the pattern towards the outer half-space. In addition, the reflective material being oriented towards the inner half-space, it does not degrade the light patterns projected by the flexible guide sheets.

[0019] Alternatively, according to the second embodiment, the reflective material at least partially covers a surface facing the outer half-space of the portion of the first flexible guide sheet extending along the second edge and of the portion of the second flexible guide sheet extending along the second edge. It is thus not necessary to bend the portions of flexible guide sheets extending along the second edge, which facilitates the manufacture of the light module, while preventing light from being emitted along the second edge.

[0020] According to embodiments, the reflective material may be a reflective paint.

[0021] Thus, the visual appearance of the projected patterns is improved without adding an additional part, and by inducing minimal additional space.

[0022] According to the first embodiment or the second embodiment, the reflective material may be a strip extending along the second edges of the first and second flexible guide webs.

[0023] Thus, the junction between the flexible guide sheets is completely covered by the reflective material, which improves the visual appearance of the patterns projected by the light module in the second embodiment and improves the light output in the first embodiment.

[0024] According to embodiments, the first flexible guide sheet can be etched so as to project a first pattern when said at least one light source injects light into the first injection element, and the second flexible guide sheet can be etched so as to project a second pattern when said at least one light source injects light into the second injection element, the first and second patterns arranged next to each other can together form at least one light symbol.

[0025] The invention is particularly advantageous in the case where such a luminous symbol is produced from several patterns of several flexible guide sheets. Without the invention, such a symbol would have been interspersed with a luminous strip at the junction between the flexible guide sheets.

[0026] Additionally, the reflective material strip can be interrupted on the light symbol. This optimizes the projection of the patterns that form a light symbol, without being degraded by the junction between several flexible guide sheets. The light output associated with the light module is also improved.

[0027] According to the first embodiment or the second embodiment, at least one of the flexible guide sheets may further comprise a third edge distinct from the first and second edges, wherein at least a portion of the flexible guide sheet extending along the third edge is covered with a reflective material on a surface facing the outer half-space.

[0028] Edge effects are thus avoided on the edge(s) of a flexible guide sheet not forming a junction with another flexible guide sheet.

[0029] According to embodiments, the light source may be capable of selectively injecting light into a first optical fiber connected to the first injection element and into a second optical fiber connected to the second injection element.

[0030] A single light source can thus be offset from the flexible guide sheets and injection elements, which facilitates the integration of the light module, particularly in equipment with significant space constraints.

[0031] According to embodiments, the assembly may include more than two flexible guide webs placed adjacent to each other so as to form a matrix of flexible guide webs.

[0032] This makes it possible to produce large light modules with complex patterns.

[0033] According to embodiments, a dimension of the flexible guide sheets can be between 3 and 25 cm.

[0034] This makes it possible to produce large light modules.

[0035] According to embodiments, each flexible guide sheet of the assembly may have a thickness of between 0.2 and 1 mm. Thus, the guide sheets have significant flexibility, which facilitates their integration.

[0036] According to embodiments, each flexible guide sheet may comprise a film comprising microstructures, each pattern among the first and second patterns may be etched by ultraviolet printing of the microstructures of the film.

[0037] Such microstructures allow maintaining a high level of transparency of the flexible guide sheet while projecting light into the illuminated area when the light source is activated.

[0038] Additionally, for each flexible guide sheet, a surface density of microstructures can decrease with the distance from the edge of the guide sheet into which the light is injected.

[0039] The homogeneity of a pattern projected by the flexible guide sheet is thus improved.

[0040] Other characteristics and advantages of the invention will appear on examining the detailed description below, and the appended drawings in which:

[0041] [Fig 1] illustrates part of a light module according to the invention;

[0042] [Fig 2] illustrates an injection element of a light module according to an embodiment of the invention;

[0043] [Fig 3] illustrates a light module according to the invention;

[0044] [Fig 4] illustrates a light module according to a first embodiment of the invention;

[0045] [Fig 5] illustrates a light module according to a second embodiment of the invention.

[0046] The description focuses on the features that distinguish the light module from those known in the state of the art.

[0047] Figure 1 shows a part of a light module 100 according to the invention.

[0048] The light module 100 comprises a flexible guide sheet 110 capable of receiving light rays via a first edge 114 and of returning the light rays in a direction Z substantially normal to a surface of the flexible guide sheet which thus extends in an XY plane in FIG. 1.

[0049] A guide sheet is understood to mean an optical guide element one of whose dimensions is much smaller than the other two dimensions in space, for example one or more orders of magnitude smaller. As illustrated in FIG. 1, a flexible guide sheet is considered here whose thickness along the Z axis is at least two orders of magnitude smaller than its dimensions along the XY plane in which the flexible guide sheet 110 extends.

[0050] The flexible guide sheet 110 may comprise a flexible film 111 at its core comprising at least one first edge 114 capable of guiding the light rays in a global direction X, and comprising a set of microstructures 113 capable of returning the light rays guided in the flexible film 111 outside the flexible guide sheet 110, in particular in one or more directions substantially along the Z axis.

[0051] The flexible film 111 may be a substrate film made of polycarbonate, PC, polymethyl methacrylate, PMMA, thermoplastic polyurethane, TUP, or polyethylene terephthalate, PET. The flexible film 111 may have a thickness, i.e. a dimension along the Z axis, of between 12 and 1000 micrometers. More specifically, the thickness of the flexible film 111 may be between 50 and 1000 micrometers, for example between 200 and 500 micrometers. Alternatively, it is the flexible guide sheet 110 which has a thickness of between 200 and 1000 micrometers.

[0052] The aforementioned materials, combined with a low thickness as described above, make it possible to obtain a flexible film 111. Other materials may be provided for the composition of the flexible film 111. However, it is preferable according to the invention to provide deformable and transparent materials.

[0053] A thin coating of microstructures 113 may be applied to one of the faces of the flexible film 111, or may be integrated into the flexible film 111. The coating of microstructures 113 may in particular have a thickness along the Z axis of less than 20 micrometers. Such microstructures 113 may have a general bump shape, on which the light rays are reflected in a direction substantially along the Z axis. Such microstructures 113 may be capable of causing the light rays emerging from the flexible film 111 to form a pattern. For this purpose, the microstructures 113 may be etched by ultraviolet printing, according to the desired pattern.

[0054] Microstructures 113 are structures or irregularities of the flexible film, the dimensions of which are less than a few micrometers. The microstructures thus also cover nanometric structures. Such sizes of microstructures 113 make it possible to ensure high transparency of the flexible film 111. In particular, a transparency of the order of 97% can be obtained in practice by the use of microstructures 113. Alternatively, the flexible guide sheet can be semi-transparent or opaque.

[0055] Advantageously, the microstructures 113 can be distributed along the X axis so that a linear density of microstructures 113 is proportional to the distance from the first edge 114 by which the light rays injected by the injection element 120 are received. In other words, the further the microstructures 113 are from the first edge 114, the more densely they are grouped. Such a distribution advantageously makes it possible to ensure a homogeneous distribution along the X axis of the light intensity of the pattern emitted by the flexible guide sheet 110.

[0056] The flexible guide sheet 110 may further comprise one or two optional protective layers 112.1 and 112.2, which make it possible to mechanically protect the flexible film 111. In addition, at least one of the protective layers 112.1 and 112.2 may comprise an anti-UV treatment, making it possible to protect the flexible film against UV rays, once the microstructures 113 have been etched. Without such UV protection, the pattern projected by the flexible guide sheet 110 is likely to degrade over time, in particular when exposed to sunlight.

[0057] The flexible film 111 and the protective layers 112.1 and 112.2 are shown spaced apart in FIG. 1, for illustrative purposes only. It will be understood, however, that the protective layers 112.1 and 112.2 may be joined to the flexible film, in particular by lamination. Since the guide sheet 110 is flexible, it is not necessarily included in a plane but may be curved, depending on the position in which it is placed and the mechanical stresses applied to it.

[0058] The part of the light module 100 illustrated in FIG. 1 also comprises a light injection element 120, also called a light bar, because it extends longitudinally in a Y direction, and is capable of injecting light in a direction normal to its longitudinal direction, for example along the X axis when it is arranged in the manner shown in FIG. 1.

[0059] The light injection element 120 is of rectangular or square cross-section in FIG. 1. However, the light injection element 120 may have a round, oval, or polygonal cross-section.

[0060] Thus, the light injection element 120 comprises an output surface 122 extending in the longitudinal direction and capable of injecting light in a direction substantially normal to the output surface 122. The light injection element 120 further comprises an input surface 121, at one end of the light injection element 120, capable of receiving light rays from a light source 130, and the light injection element 120 is capable of guiding the light longitudinally along the Y axis by distributing it on the output surface 122. The distribution of light by the output surface 122 will be better understood in light of the description of FIG. 2.

[0061] No restrictions are attached to the light source 130. It may for example be an electroluminescent source of the LED type for example, having the advantage of small size, low energy consumption and low heating. The light source 130 may be capable of generating light in a range of wavelengths. Such an interval may be centered around a visible color, in order to generate colored light, for example 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 restricted range of wavelengths may be produced by a laser-type light source 130.Alternatively, the light source 130 is not arranged directly opposite the entry surface 121 of the injection element 120, but the light module 100 further comprises an optical fiber placed between the source 130 and the injection element 120, which makes it possible to offset the source 130 relative to the assembly formed by the injection element 120 and the flexible guide sheet 110.

[0062] Figure 2 shows an injection element 120 of a light module 100 according to one embodiment of the invention.

[0063] The injection element 120 may comprise a plurality of injection guides 123 capable of receiving light from the source 130 via the input surface 121 and of guiding the light to a longitudinal position of the output surface 122, the longitudinal positions of the light guides being distinct so as to distribute the light to at least several longitudinal positions of the output surface 122.

[0064] It is thus made possible to inject light at different longitudinal positions along the Y axis of the first edge 114. Each longitudinal position of the first edge 114 can correspond to a guide line of the flexible film 111, capable of guiding the light along the X axis along such a guide line.

[0065] Such an association of a flexible guide sheet 110, an injection element 120 and a source 130 thus makes it possible to project light in the Z direction via a flexible, transparent, semi-transparent or opaque surface, with good surface homogeneity and according to a given pattern.

[0066] In practice, such a light module can emit a pattern with a brightness of between 100 and 1000 Candelas per square meter, with a light extraction efficiency that can vary between 25% and 80%.

[0067] Details of the structure and arrangement of elements 110, 120 and 130 are further described in the international patent application published under number WO2011130715A2.

[0068] Figure 3 shows a front view of a light module 300 according to the invention.

[0069] The light module 300 according to the invention comprises: - a set of at least two flexible guide sheets, comprising a first flexible guide sheet 310.1 and a second flexible guide sheet 310.2, similar to the flexible guide sheet 110 illustrated in FIG. 1;

[0070] - at least a first light injection element 320.1 and a second light injection element 320.2 respectively associated with the first and second flexible guide sheets 310.1 and 310.2, each light injection element being able to be the injection element 120 described with reference to figures 1 and 2; and

[0071] - at least one light source such as the light source 130 previously described with reference to FIG. 1, capable of injecting light selectively into the first and second injection elements. In FIG. 3, an embodiment with a first light source 330.1 placed opposite the entry surface of the first injection element 320.1, and a second light source 330.2 placed opposite the entry surface of the second injection element 320.2, are shown, for illustration purposes.

[0072] The first injection element 320.1 is capable of injecting light from the first light source 330.1 into a first edge, such as the edge 114 previously described, of the first flexible guide sheet 320.1.

[0073] The second injection element 320.2 is capable of injecting light from the second light source 330.2 into a first edge, such as the edge 114 previously described, of the second flexible guide sheet 320.2.

[0074] In the light module 300 according to the invention, the first flexible guide sheet 310.1 and the second flexible guide sheet 310.2 are arranged next to each other in such a way that a second edge 350.1 of the first flexible guide sheet 310.1 is arranged opposite a second edge 350.2 of the second flexible guide sheet 320.2.

[0075] The first flexible guide sheet 310.1 is etched according to a first pattern 340.1 and the second flexible guide sheet 340.2 is etched according to a second pattern. As shown in FIG. 1, the first and second patterns 340.1 and 340.2 may together form at least one symbol 341. Alternatively, each pattern of a flexible guide sheet may form a symbol independently of the other flexible guide sheets, or may not form any symbol, which is the case when the pattern is a spatial modulation of the emitted light without any apparent shape or symbol.

[0076] In the following, the example of two patterns together forming a symbol 341 is considered, for illustrative purposes only. The symbol 341 thus corresponds to a luminous zone in the first flexible guide sheet and to a complementary luminous zone in the second flexible guide sheet.

[0077] There is no restriction on the number of flexible guide sheets that the light module according to the invention comprises. The light module may in particular comprise more than three flexible guide sheets, distributed in a row, or in a matrix with at least two rows and at least two columns. In this case, at least one of the flexible guide sheets has two second edges facing second edges of two other flexible guide sheets.

[0078] A “second edge” of a flexible guide web is any edge of the flexible guide web facing, or adjoining, another second edge of another flexible guide web. An example in which each flexible guide web comprises a single second edge is shown in Figure 3, for illustrative purposes only.

[0079] A portion 360.1 of the first flexible guide web 310.1 extends along the second edge 350.1 of the first flexible guide web 310.1.

[0080] A portion 360.2 of the second flexible guide web 310.2 extends along the second edge 350.2 of the second flexible guide web 310.2.

[0081] No restriction is attached to the width of the portion 360.1 which may be a fraction of a dimension of the first flexible guide web 310.1, just as the portion 360.2 may be a fraction of a dimension of the second flexible guide web 310.2. The portion 360.1 may for example be less than one tenth of the width, or dimension along the Y axis, of the first flexible guide web 310.1. The portion 360.2 may also be less than one tenth of the width, or dimension along the Y axis, of the second flexible guide web 310.2. The first and second flexible guide webs 310.1 and 310.2 may have the same shape and the same dimensions.

[0082] For example, the first and second flexible guide webs 310.1 and 310.2 may be rectangular or square in shape. The first and second flexible guide webs 310.1 and 310.2 may have dimensions along the X and Y axes in which they extend, between 3 and 25 cm.

[0083] “Pattern” means any predefined spatial distribution or distribution of the light intensity emitted by the light module. In particular, reference is made here to a two-dimensional or one-dimensional pattern. A pattern may thus be a two-dimensional shape or symbol obtained by contrast between the light intensities of different positions in the XY plane of the flexible guide sheet 110. The pattern may also comprise several shapes or symbols. Alternatively, a pattern covers a predefined, or intentional, spatial distribution of the light intensity not showing a general shape, such as a distribution inducing a cloud of light points. In the context of the present invention, a pattern is formed by injecting light into an injection element which is arranged relative to a flexible guide sheet so as to form the pattern on the flexible guide sheet.

[0084] Each flexible guide sheet may optionally include at least a third edge, which is an edge distinct from the first light-receiving edge and distinct from a second edge adjoining another flexible guide sheet. The first flexible guide sheet

[0085] 310.1 may include such a third edge 370.1 and the second flexible guide sheet

[0086] 310.2 may include such a third edge 370.2.

[0087] The characteristics presented of the light module 300 with reference to FIG. 3 apply to the two embodiments described below.

[0088] Figure 4 shows a sectional view of a light module 400 according to a first embodiment of the invention.

[0089] The section shown is in the YZ plane. The light module 400 delimits an exterior half-space, located above the light module 400, and an interior half-space, located below the light module 400. No limitation is associated with the adjectives “exterior” and “interior” which are relative, and allow the half-spaces to be named.

[0090] In the first embodiment, the portions 360.1 and 360.2 extending along the second edges 350.1 and 350.2 are folded towards the interior half-space defined by the light module 400.

[0091] This avoids projecting a beam of light into the junction area between parts 360.1 and 360.2. This makes it possible to produce a light module with a large emitting surface, as it comprises several flexible guide sheets, without degrading the quality of the projected patterns.

[0092] Such a first embodiment is particularly advantageous when the patterns produced by the flexible guide sheets together produce a pattern or symbol, as is the case in FIG. 3. The first embodiment thus makes it possible to produce such a pattern without an untimely light line or band degrading the visual appearance of the pattern or symbol 341.

[0093] Optionally, the light module 400 may comprise a support 410 arranged in the interior half-space and capable of holding the first and second flexible guide sheets. The support 410 comprises a cavity 411 shaped so as to receive the folded portion 360.1 of the first flexible guide sheet as well as the folded portion 360.2 of the second flexible guide sheet. It will be understood that the cavity 411 extends on the X axis along the second edges 350.1 and 350.2.

[0094] When the light module 400 comprises a matrix of flexible guide sheets, the cavities 411 can form a grid in the support 410. No restriction is attached to the fixing means between the support 410 and the flexible guide sheets, which can comprise mechanical means by clamping or clipping, or alternatively means of fixing by gluing.

[0095] The support 410 is capable of supporting and shaping the flexible guide sheets 310.1 and 310.2. The support 410 may have a flat surface for contact with the flexible guide sheets, or, on the contrary, may have a non-flat surface, with bumps or angles.

[0096] In addition, optionally, the parts 360.1 and 360.2 may be covered, partially or in part, with a reflective material 420, which covers a surface of the parts 360.1 and 360.2 facing the interior half-space, i.e. downwards in FIG. 4. The reflective material 420 may, for example, be a reflective paint. Such an embodiment is advantageous for returning light rays into the flexible guide sheet so as to illuminate according to the pattern of each flexible guide sheet. The light output of the light module 400 is thus improved. Thus, a strip of material 420 extends over the junction zone between the two parts 360.1 and 360.2 on the surface facing the interior half-space, i.e. opposite the surface onto which the patterns are projected, which makes it possible not to damage the projected patterns.

[0097] Furthermore, optionally, a reflective material 421, identical to the reflective material 420, may at least partially cover a portion of each flexible guide sheet extending along the third edges 370.1 and 370.2. This avoids edge effects on the third edges which are ends of the light module.

[0098] Figure 5 illustrates a sectional view of a light module 500 according to a second embodiment of the invention.

[0099] In the second embodiment, the parts 360.1 and 360.2 of the flexible guide sheets 310.1 and 310.2 are not folded.

[0100] To prevent the light rays guided in the flexible guide sheets from forming a light band along the second edges 350.1 and 350.2, a reflective material 520 at least partially covers the parts 360.1 and 360.2 previously described on a surface oriented towards the outer half-space of the light module, i.e. upwards in FIG. 5.

[0101] No restriction is attached to the reflective material 520, which may for example be a reflective paint. The light module 500 may also comprise a support 510 which, unlike the support 410 previously described, does not have to comprise a cavity 411 which facilitates the manufacture of such a support 510.

[0102] No restriction is attached to the means of attachment between the support 410 and the flexible guide sheets, which may comprise mechanical means by clamping or clipping, or alternatively means of attachment by gluing.

[0103] The 510 support is capable of supporting and shaping the flexible guide webs.

[0104] 310.1 and 310.2. The support 510 may have a flat surface for contact with the flexible guide sheets, or on the contrary, may have a non-flat surface, with bumps or angles.

[0105] The 520 material strip may be interrupted in the bright areas of the patterns

[0106] 340.1 and 340.2, in particular when a symbol, such as symbol 341, is partially in the junction area between the two flexible guide sheets. The strip of material therefore does not hide symbol 341.

[0107] Furthermore, optionally, a reflective material 521, identical to the reflective material 520, may at least partially cover a portion of each flexible guide sheet extending along the third edges 370.1 and 370.2. This avoids edge effects on the third edges which are ends of the light module.

[0108] The present invention is not limited to the embodiments described above as examples; it extends to other variants.

Claims

Demands 1. Light module (300; 400; 500) comprising: • an assembly of at least two flexible guide sheets (110; 310.1; 310.2), comprising a first flexible guide sheet and a second flexible guide sheet, each flexible guide sheet of the assembly being capable of receiving light rays through at least a first edge (114) of said flexible guide sheet and of reflecting the light rays in a direction substantially normal to a surface of the flexible guide sheet according to at least one pattern engraved in said flexible guide sheet; • at least one first light injection element (120; 320.1; 320.2) capable of receiving light and distributing light in the first flexible guide sheet and a second light injection element capable of receiving light and distributing light in the second flexible guide sheet; • at least one light source (130; 330.1; 330.22) capable of injecting light into the first light injection element and into the second light injection element; wherein the first flexible guide sheet and the second flexible guide sheet are arranged side by side so that a second edge (350.1) of the first flexible guide sheet is opposite a second edge (350.2) of the second flexible guide sheet; in which the first flexible guide sheet and the second flexible guide sheet delimit an outer half-space towards which the light rays are emitted in the direction substantially normal to the surface of the flexible guide sheets, and an inner half-space of the light module, complementary to the outer half-space; and in which a part of the first flexible guide sheet extends along the second edge and a part of the second flexible guide sheet extends along the. second edge are folded towards the inner half-space or are covered at least partially with a reflective material (420; 520; 421; 521).

2. Light module according to claim 1, further comprising a support (410) arranged in the inner half-space and capable of holding the assembly of at least two flexible guide sheets (110; 310.1; 310.2), said support comprising a cavity (411) capable of receiving the folded part of the first flexible guide sheet and the folded part of the second flexible guide sheet.

3. Light module according to claim 1 or 2, wherein part (360.1) of the first flexible guide sheet (310.1) extending along the second edge (350.1) and part (360.2) of the second flexible guide sheet (310.2) extending along the second edge (350.2) are folded towards the inner half-space and the reflective material (420) covers at least partially a surface of the folded parts oriented towards the inner half-space.

4. Light module according to claim 1, wherein the reflective material (520) covers at least partially a surface oriented towards the outer half-space of the part (360.1) of the first flexible guide sheet (310.1) extending along the second edge (350.1) and of the part (360.2) of the second flexible guide sheet (310.2) extending along the second edge (350.2).

5. Light module according to any one of the preceding claims, wherein the reflective material (420; 520) is a reflective paint.

6. Light module according to any one of the preceding claims, wherein the reflective material (420; 520) is a strip extending along the second edges (350.1; 350.2) of the first and second flexible guide sheets (310.1; 310.2).

7. A light module according to any one of the preceding claims, wherein the first flexible guide web (310.1) is engraved so as to project a first pattern (340.1) when said at least one light source (130; 330.1; 330.22) injects light into the first injection element (320.1), and the second flexible guide web (310.2) is engraved so as to project a second pattern (340.2) when said at least one light source injects light into the second injection element (320.2), wherein the first and second patterns arranged side by side together form at least one light symbol (341).

5. A light module according to claims 4, 6, and 7, wherein the strip of reflective material (420; 520) is interrupted at the light symbol (341).

9. A light module according to any one of the preceding claims, wherein at least one of the flexible guide sheets (110; 310.1; 310.2) further comprises a third edge (370.1; 370.2) distinct from the first and second edges, wherein at least a portion of the flexible guide sheet extending along the third edge is covered with a reflective material (421; 521) on a surface oriented towards the outer half-space.

10. A light module according to any one of the preceding claims, wherein the assembly comprises more than two flexible guide sheets (310.1; 310.2) placed side by side so as to form a matrix of flexible guide sheets.

11. A light module according to any one of the preceding claims, wherein one dimension of the flexible guide sheets (110; 310.1; 310.2) is between 3 and 25 cm.

12. Light module according to any one of the preceding claims, wherein each flexible guide sheet (110; 310.1; 310.2) of the assembly has a thickness between 0.2 and 1 mm. A module according to any one of the preceding claims, wherein each flexible guide sheet (110; 310.1; 310.2) comprises a film (111) including microstructures (113), wherein each pattern (340.1; 340.2) among the first and second patterns is etched by ultraviolet printing of the film's microstructures. A module according to claim 13, wherein, for each flexible guide sheet (110; 310.1; 310.2), the surface density of microstructures (113) decreases with distance from the edge of the guide sheet into which light is injected.

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