Light-emitting device with optical guidance element

Abstract

Light-Emitting Device with Optical Guiding Element This description relates to a light-emitting device comprising at least: - an optical guiding element; - a light source at least partially transparent to at least one light intended to be emitted by the light source, and configured to emit the light at least on the side of a first face disposed opposite the optical guiding element and on the side of a second face opposite the first face; - a reflective layer disposed on the side of the second face of the light source; - an optical component disposed between the reflective layer and the optical guiding element and at least partially transparent to the light intended to be emitted by the light source; and in which the reflective layer forms at least one reflective surface conforming to a non-planar surface of the optical component on which the reflective layer is disposed. Figure for the abstract: Fig. 1

Description

Title of the invention: Light-emitting device with optical guidance element. Technical field

[0001] This description relates generally to light-emitting devices with an optical guiding element, or light guiding element. Previous technique

[0002] Photodynamic therapy, or PDT, is a treatment technique that destroys tissues of tumor or non-tumor origin through the combined action of a photosensitive active ingredient injected into the tissues and illumination of the tissues by a light source at an appropriate wavelength (in the visible range) to enable photoactivation of the active ingredient, leading to the destruction of the targeted tissues by cell death. The reaction that occurs is complex and involves the local presence of oxygen, and therefore the presence of local perfusion. One of the main problems with this technique is the short penetration distance of light into the tissues.Indeed, light does not penetrate the skin sufficiently due to the absorption and scattering of photons in the tissues it must traverse, and therefore cannot properly activate the photosensitive molecules injected into the tissues. These molecules are distributed from the surface down to several hundred micrometers below the skin's surface, depending on the injection method used. Consequently, the treatment's effectiveness is significantly reduced, and only pathologies close to the skin's surface can be treated with this technique.

[0003] To circumvent this problem, it is possible to use very high light intensity and / or longer exposure times (within regulatory limits) to deliver the amount of optical energy necessary to activate the photosensitive molecules within the tissues. However, in this case, it is possible to damage the microcirculation of neighboring healthy tissues, or the microcirculation of the overexposed superficial layers, or to fail to achieve the desired treatment depth. Furthermore, under certain lighting conditions, this exposure can cause severe pain (severe photochemical burns).

[0004] Another solution to the problem of light scattering in tissues involves using microneedles that act as light guides. These microneedles are inserted into the skin and tissues to a depth slightly less than their length, for example, several hundred microns. This configuration makes it possible to expose the deeper tissue layers via the light guidance provided by the microneedles, thus reducing the dose. This method irradiates the skin's surface while effectively reaching deeper areas. Light can be introduced into the microneedles via a wide-field illumination system or through microlenses positioned above them. Using microlenses focuses the light directly onto the microneedles. In this solution, the light is directed towards the microneedles for better distribution within the skin. However, surface illumination is either eliminated or significantly reduced.

[0005] Similar optical guidance problems can be encountered in other fields such as optical communications, for example when it comes to optimizing the coupling of light in a waveguide. Summary of the invention

[0006] There is a need to propose a solution that addresses at least some of the disadvantages outlined above.

[0007] One embodiment overcomes all or part of these drawbacks and proposes a light-emitting device comprising at least:

[0008] - an optical guiding element;

[0009] - a light source at least partially transparent to at least one light intended to be emitted by the light source, and configured to emit light at least on the side of a first face arranged opposite the optical guiding element and on the side of a second face opposite the first face;

[0010] - a reflective layer disposed on the side of the second face of the source luminous;

[0011] - an optical component disposed between the reflective layer and the guiding element optical and at least partially transparent to the light intended to be emitted by the light source;

[0012] and wherein the reflective layer forms at least one reflective surface conforming to a non-planar surface of the optical component on which the reflective layer is disposed.

[0013] According to a particular embodiment, the light source comprises at least one organic light-emitting diode.

[0014] According to a particular embodiment, the reflective layer is one of the electrodes of the organic light-emitting diode.

[0015] According to a particular embodiment, the reflective surface comprises at least one concave or convex part.

[0016] According to a particular embodiment, the reflective surface forms at least one spherical or conical or hyperbolic mirror.

[0017] According to a particular embodiment, the reflective layer comprises at least one metallic layer and / or at least one Bragg mirror.

[0018] According to a particular embodiment, the light-emitting device further comprises at least one substrate that is at least partially transparent to the light intended to be emitted by the light source and is disposed between the optical guiding element and the light source.

[0019] According to a particular embodiment, the optical guidance element comprises at least one microneedle at least partially transparent to the light intended to be emitted by the light source, or at least one waveguide.

[0020] According to a particular embodiment, the optical guidance element comprises a base at least partially transparent to the light intended to be emitted by the light source and several microneedles at least partially transparent to the light intended to be emitted by the light source and each comprising a first end integral with the base, the base being disposed between the light source and the microneedles.

[0021] According to a particular embodiment, the optical guidance element comprises several microneedles at least partially transparent to the light intended to be emitted by the light source, and in which the optical component comprises a layer of material at least partially transparent to the light intended to be emitted by the light source, the layer of material comprising hollows aligned with the microneedles.

[0022] According to a particular embodiment, the light source comprises several distinct parts configured to emit lights of different wavelengths, each of said parts being arranged opposite at least one of the microneedles.

[0023] According to a particular embodiment, the light source is configured to emit part of the light between the microneedles.

[0024] According to a particular embodiment, at least a part of the reflective surface is configured to reflect a part of the light emitted from the side of the second face of the light source between the microneedles.

[0025] A method for implementing a light-emitting device is also proposed, comprising at least:

[0026] - realization of at least one optical guidance element;

[0027] - realization of at least one light source that is at least partially transparent to at least one light intended to be emitted by the light source, and configured to emit the light at least on the side of a first face arranged opposite the optical guiding element and on the side of a second face opposite the first face;

[0028] - fabrication of at least one reflective layer disposed on the side of the second face from the light source;

[0029] - realization of at least one optical component disposed between the reflective layer and the optical guiding element is at least partially transparent to the light intended to be emitted by the light source;

[0030] and in which the reflective layer is made such that it forms at least one reflective surface conforming to a non-planar surface of the optical component on which the reflective layer is disposed.

[0031] According to a particular embodiment:

[0032] - the light source and the reflective layer are made on the guiding element optics, or

[0033] - the light source and the reflective layer are made on a substrate at least partially transparent to the light intended to be emitted by the light source, the substrate being then attached to the optical guiding element, or

[0034] - the light source, the reflective layer and the optical component are made on a substrate opaque to the light intended to be emitted by the light source, the optical component is then attached to the optical guiding element. Brief description of the drawings

[0035] These features and advantages, as well as others, will be described in detail in the following description of particular embodiments, given by way of non-limiting example, in relation to the accompanying figures, among which:

[0036] - Figure 1 schematically represents an example of a light-emitting device according to a first embodiment;

[0037] - [Fig. 2] shows examples of light focusing obtained with different forms of reflective surface in a light-emitting device;

[0038] - [Fig.3], [Fig.4], [Fig.5], [Fig.6], [Fig.7], [Fig.8], [Fig.9] and [Fig. 10] represent steps in an example of a process for making a light-emitting device according to the first embodiment;

[0039] - Figure 11 schematically represents an example of a light-emitting device according to a variant of the first embodiment;

[0040] - Figure 12 schematically represents an example of a light-emitting device according to a second embodiment;

[0041] - [Fig. 13] schematically represents an example of a light-emitting device according to a variant of the second embodiment;

[0042] - Fig. 14, Fig. 15, Fig. 16 and Fig. 17 represent stages of a method for making a light-emitting device according to the second embodiment;

[0043] - Fig. 18, Fig. 19, Fig. 20 and Fig. 21 represent stages of a method of making a light-emitting device according to another variant of the second embodiment. Description of the implementation methods

[0044] The same elements have been designated by the same reference numerals in the different figures. In particular, the structural and / or functional elements common to the different embodiments may have the same reference numerals and may have identical structural, dimensional and material properties.

[0045] In the figures, in order to facilitate their reading, the different elements and the different layers of materials are not represented at the same scale relative to each other.

[0046] For the sake of clarity, only the steps and elements useful for understanding the described embodiments have been represented and are detailed.

[0047] Unless otherwise specified, when referring to two elements connected together, this means directly connected without intermediate elements other than conductors, and when referring to two elements linked or coupled together, this means that these two elements can be connected or linked through one or more other elements.

[0048] In the following description, when reference is made to absolute positional qualifiers, such as "front," "back," "top," "bottom," "left," "right," etc., or relative positional qualifiers, such as "above," "below," "superior," "inferior," "lateral," etc., or to orientational qualifiers, such as "horizontal," "vertical," etc., unless otherwise specified, reference is made to the orientation of the figures. However, these terms do not imply the actual position and orientation of the device during its use.

[0049] In the figures, in order to facilitate their reading, the different elements and the different layers are not represented at the same scale relative to each other.

[0050] Unless otherwise specified, the expressions "approximately", "roughly", and "in the order of" mean within 10%, preferably within 5%.

[0051] Throughout the document, the expression "at least partially transparent" is used to characterize the fact that an element can be traversed by at least some part (for example at least 40% or at least 50% or at least 70% or at least 90%) of the light received at the input of that element and / or emitted by that element.

[0052] An example of a light-emitting device 100 according to a first embodiment is described below with reference to [Fig. 1]. In this embodiment, the device 100 corresponds to a photodynamic therapy device intended for to produce light emission both on the surface of skin tissues and also deep within the tissues, beneath the outer surface of the skin.

[0053] The device 100 comprises at least one light source 102, at least partially transparent (and preferably transparent) to at least one light intended to be emitted by the light source 102. In the described embodiment, the light source 102 is organic and comprises an organic light-emitting diode, or OLED. This OLED comprises first and second electrodes (one corresponding to the anode of the OLED and the other to the cathode of the OLED) made of at least one electrically conductive material, and at least one emissive layer made of at least one organic semiconductor material and disposed between the first and second electrodes. The thickness (dimension parallel to the Z-axis in [Fig. 1]) of the OLED is, for example, between 50 nm and 500 nm. As an example, OLED electrodes may contain at least one of the following materials: Al, Ag, ITO, SnO2, etc.The OLED's emissive layer can comprise, depending on the desired wavelength, at least one of the following types of materials: Irppy, TADF (thermally activated delayed fluorescent), MR-TADF (multi-resonance thermally activated delayed fluorescent). Furthermore, the light source 102 is configured to emit light from at least two opposite faces.

[0054] A light source 102 comprising at least one OLED used in the device 100 has the advantage, compared to other types of light source, of achieving homogeneous, isotropic light emission over a large surface area. Alternatively, the device 100 may include other types of light source 102 configured to emit from two opposite sides and which is at least partially transparent to the emitted light.

[0055] The device 100 further comprises at least one optical guidance element 104. In the described embodiment, the optical guidance element 104 comprises a base 106 that is at least partially transparent (and preferably transparent) to the light intended to be emitted by the light source 102, as well as several microneedles 108 that are also at least partially transparent (and preferably transparent) to the light intended to be emitted by the light source 102 and intended to be inserted into tissues 110 corresponding to superficial layers of the skin. Each of the microneedles 108 comprises a first end 112 attached to the base 106 and a second pointed end 114. More particularly, in the described embodiment, each microneedle 108 comprises a cylindrical portion extending from the first end 112 and continuing through a conical portion extending to the second end 114. Alternatively, microneedle shapes 108 other than that described above are possible. For example, the cross-section of the microneedles 108 can be of a shape other than a disc. Furthermore, shapes other than a point are conceivable, for example, to orient the optical guiding element 104 or to couple it with a local diffuser arranged at the tip of the microneedles 108.

[0056] In the described embodiment, the microneedles 108 guide the light received at the surface of the base 106, on which the light source 102 is positioned, into the deeper layers of the skin into which the microneedles 108 are inserted. The conical shape of the tips of the microneedles 108 allows them to penetrate the skin effectively and also ensures good diffusion of the guided light in the cylindrical portion of the microneedles 108. By way of example, the height of each of the microneedles 108 (dimension parallel to the Z-axis in [Fig. 1]) can be between 100 µm and 3 mm. The cross-section of the cylindrical part of each of the microneedles 108, in a plane perpendicular to their height (plane parallel to the (X,Y) plane in the example of [Fig.1]) has for example a diameter between 50 pm and 900 pm.The pitch of the 108 microneedles, that is, the distance separating the axes of revolution of two adjacent 108 microneedles, can range from approximately 100 pm to several millimeters. According to one embodiment, the 108 microneedles may be made of a biocompatible material such as polymethyl methacrylate or PMMA, or PLGA (poly(lactic-co-glycolic acid)).

[0057] When the device 100 is intended for uses other than photodynamic therapy, the optical guidance element 104 may include the base 106 to which are optically coupled one or more elements at least partially transparent (and preferably transparent) to the light intended to be emitted by the light source 102, this or these elements may not be microneedles.

[0058] Thus, the optical guidance element 104 may include, for example, at least one microneedle, or at least one waveguide (example of an application other than photodynamic therapy), and the optical guidance element 104 may or may not include the base 106.

[0059] The light source 102 is configured to emit light at least on the side of a first face 116 arranged opposite the optical guiding element 104 and also on the side of a second face 118 opposite the first face 116. This light emission on the side of each of the faces 116, 118 is due, in this embodiment, to the fact that the light source 102 corresponds to an OLED that emits light on the side of each of its electrodes (first electrode arranged on the side of the first face 116 and second electrode arranged on the side of the second face 118). 118). Alternatively, this light emission from the two faces 116, 118 of the light source 102 can be obtained by using other types of light source 102.

[0060] In the described embodiment, the first face 116 of the light source 102 is disposed directly against the optical guiding element 104, and more particularly against the base 106 of the optical guiding element 104. Alternatively, it is possible that at least one element at least partially transparent, or preferably transparent, to the light intended to be emitted by the light source 102, for example a substrate of glass or of any other transparent or semi-transparent material, is interposed between the light source 102 and the optical guiding element 104, such as conical bases on which the microneedles are disposed, and with a possible base on which the conical bases rest.

[0061] The device 100 further comprises at least one reflective layer 120 disposed on the side of the second face 118 of the light source 102 and forming a reflective surface 122 on the side of the light source 102. This surface 122 is described as reflective because it is configured to reflect at least some, and preferably all or almost all, of the light emitted by the light source 102 on the side of its second face 118. The reflective layer 120 comprises, for example, at least one metal such as silver or aluminum. The thickness of the reflective layer 120 is, for example, between 50 nm and 500 nm.

[0062] Alternatively, the reflective layer 120 may include at least one Bragg mirror configured to reflect the wavelength(s) of interest emitted by the light source 102 to the side of its second face 118, i.e. the light intended to be sent towards the tissues 110.

[0063] In all cases, the properties of the reflective layer 120 (material(s) used, thickness, shape, etc.) can be such that the reflective surface 122 reflects as much light as possible in order to have the lowest possible light loss at the level of this reflective layer 120.

[0064] The device 100 further comprises at least one optical component 124 disposed between the reflective layer 120 and the optical guiding element 104, and more particularly between the light source 102 and the reflective layer 120 in the first embodiment. In the example of [Fig. 1], the device 100 comprises several optical components 124, each disposed opposite one of the microneedles 108. The pitch (distance between the centers of two adjacent optical components 124) with which the optical components 124 are made can be equal to that of the microneedles 108. The optical components 124 are at least partially transparent, and preferably transparent, to the light intended to be emitted by the light source 102 on the side of its second face 118. According to one embodiment, the optical components 124 comprise a resin-type polymer or an oxide such as SiO2 or SiN or any other suitable material. In addition, the thickness of each of the optical components 124 (i.e. their dimension parallel to the Z axis in the example of [Fig.1]) is for example between 50 pm and 2 mm.

[0065] The reflective layer 120 is arranged on the optical components 124 such that the reflective surface 122 conforms to a non-planar surface of the optical components 124 and thus achieves light reflection with a desired directivity and / or focus. Therefore, the geometry of the reflective surface 122 opposite each microneedle 108 depends on that of the non-planar surface of each optical component 124. In the described embodiment, each optical component 124 forms a concave surface on which the reflective layer 120 is arranged, this shape corresponding to that of the reflective surface 122. For example, the optical components 124 may be such that the reflective surface 122 forms, opposite each microneedle 108, at least one spherical, conical, or hyperbolic mirror.Alternatively, each optical component 124 may have a convex shape or another non-planar shape suitable for achieving a desired light reflection. For example, the optical components 124 may be such that, combined with the reflective surface 122, they allow the directivity of the light to be locally increased in order to reflect it at a suitable angle into the optical guiding element 104.

[0066] Furthermore, the optical components 124 combined with the reflective surface 122 can be configured to focus the light emitted by the light source 102 on the side of the second face 118 into each of the microneedles 108, as illustrated by the arrows designated by reference numeral 125. The choice of the shape of the non-planar surface of the optical components 124 on which the reflective surface 122 of the reflective layer 120 is disposed can depend on the desired focusing of the light into the optical guiding element 104, and more particularly into the microneedles 108 in the example described. In [Fig. 2], view a) represents the focusing obtained on the surface of an optical guiding element 104 through which the light enters, when the reflective surface 122 forms a spherical mirror, and view b) represents the focusing obtained when the reflective surface 122 forms a conical mirror.These figures show that the focusing achieved is greater when the reflecting surface 122 forms a conical mirror than when it forms a spherical mirror.

[0067] In the first embodiment, the light source 102 is configured to emit, from its first face 116, a portion of the light into the microneedles 108 and another portion of the light between the microneedles 108. The light source 102 is also configured to emit, from its second face 118, a portion of the light into the microneedles 108 after passing through the optical components. 124, having been reflected off the reflective surface 122 and having passed again through the optical components 124 and the light source 102, and another part of the light between the microneedles 108 after being reflected off the parts of the reflective layer 120 arranged between the optical components 124 and having passed through the light source 102. Indeed, the parts of the second face 118 of the light source 102 not covered by the optical components 124 are directly covered by the reflective layer 120. Thus, in the described embodiment, this part of the light sent between the microneedles 108 enters directly into the tissues 110 from the outer surface of the skin, while the part of the light sent into the microneedles 108 is reflected against the walls of the cylindrical part of the microneedles 108 before exiting into the tissues 110 at the conical parts of the microneedles 108.Thus, thanks to device 100, light is sent both to the surface of tissues 110 (corresponding to superficial skin irradiation) and also to different depths of tissues 110. The light sent into tissues 110 by device 100 is therefore not localized only on the surface or only deep within tissues 110. This allows, in the case of using device 100 for photodynamic therapy, to obtain optimal effectiveness of the treatment carried out, at different depths of tissues 110.

[0068] As an alternative to the first embodiment described above, the optical guiding element 104 can be a waveguide. In this case, the reflective layer 120 and the optical component(s) 124 increase the light intensity sent into this waveguide because the light emitted from the second face 118 of the light source 102 can be reflected and focused towards the waveguide. The device 100 according to such an alternative can, for example, be used in the field of optical communications to optimize the coupling of light in the waveguide corresponding to the optical guiding element 104.

[0069] An example of a method for implementing device 100 according to the first embodiment is described below in relation to figures 3 to 10.

[0070] In this example, the light source 102, the reflective layer 120, and the optical components 124 are made on a substrate 126 that is at least partially transparent to the light intended to be emitted by the light source 102. The thickness of the substrate 126 is, for example, a few hundred microns. Alternatively, the light source 102, the reflective layer 120, and the optical components 124 may be made directly on the optical guiding element 104, as is the case in the example in [Fig. 1].

[0071] In the described embodiment, the light source 102 is an OLED. Thus, in this example, a first electrode 128 is transparent or semi-transparent, that is, capable of allowing at least some of the light to pass through. intended to be emitted from the emitting layer(s) of the light source 102, is made on the substrate 126. The first electrode 128 corresponds for example to the anode of the OLED forming the light source 102. A contact pad 130 to which a second electrode of the light source 102 is intended to be electrically coupled is also made on the substrate 126, next to the first electrode 128 (see [Fig.3]).

[0072] An insulating portion 132, comprising for example resin, is then formed, for example by deposition, around the periphery of the first electrode 128 (see [Fig. 4]). This insulating portion 132 is intended to electrically isolate the first electrode 128 from the electrical connection that will be made between the second electrode of the light source 102 and the contact pad 130.

[0073] One or more emissive layers 134, comprising here at least one organic material, are then deposited on the first electrode 128 (see [Fig.5]).

[0074] A second transparent or semi-transparent electrode 136 is formed on the emissive layer(s) 134. This second electrode 136 corresponds, for example, to the cathode of the OLED forming the light source 102. A portion of this second electrode 136 is deposited on at least one lateral side of the emissive layer(s) 134, on a portion of the insulating portion 132, and on a portion of the substrate 126 so as to be in contact with the contact pad 130 (see [Fig. 6]). At this stage of the process, the fabrication of the light source 102 is complete.

[0075] Although not visible, a transparent or semi-transparent encapsulation layer can be deposited on the light source 102.

[0076] The optical components 124 are then made on the light source 102. In the described embodiment example, pads 138 of the material intended to form the optical components 124, for example pads of transparent or semi-transparent resin, are made for example by deposition above the second electrode 136, for example on the encapsulation layer (see [Fig.7]).

[0077] A finishing step can then be implemented to give the pads 138 the desired shape and thus form the optical components 124 (see [Fig.8]).

[0078] The reflective layer 120 is then produced, for example by deposition, on the optical components 124 and on the parts of the second electrode 136 not covered by the optical components 124 (see [Fig.9]).

[0079] The device 100 is completed by transferring the structure made onto the guide element 104 comprising, in the described embodiment, the base 106 and the microneedles 108. This transfer corresponds, in the described example, to a securing of the substrate 126 against the base 106 (see [Fig. 10]).

[0080] In one embodiment, the light source 102 can be made such that it comprises several distinct parts configured to emit light of wavelengths different and which are each arranged opposite at least one of the microneedles 108. An example of an embodiment of a device 100 according to such a variant is shown in [Fig. 11]. In this figure, the emitting layer(s) 134 comprise first emitting parts 140 and second emitting parts 142 arranged alternately next to each other on the first electrode 128. According to one embodiment, the first emitting parts 140 can be configured to emit red light (which has the property of penetrating the epidermis well), and the second emitting parts 142 can be configured to emit blue light (which has the property of being well absorbed by the active ingredient used in phototherapy treatments).

[0081] Alternatively, the light source 102 can be configured to emit wavelengths different from the examples described above, and / or a greater number of different wavelengths.

[0082] An example of a light-emitting device 100 according to a second embodiment is described below in relation to [Fig. 12].

[0083] In this second embodiment, the device 100 comprises the optical guidance element 104 formed by the base 106 and the microneedles 108. The optical components 124 are arranged on the base 106 of the optical guidance element 104.

[0084] Unlike the first embodiment in which the light source 102 is arranged between the optical guiding element 104 and the optical components 124, and with the reflective layer 120 formed above the optical components 124, here the optical components 124 are arranged on the optical guiding element 104, with the light source 102 arranged on the optical components 124. In other words, the optical components 124 are arranged here between the optical guiding element 104 and the light source 102. Furthermore, in this second embodiment, the reflective layer 120 corresponds to one of the electrodes of the OLED forming the light source 102 and corresponds to the one forming an outer layer of the light source 102 (i.e., the one that is not arranged directly against the optical components 124).For this electrode to form the reflective layer 120, and therefore the reflective surface 122, this electrode comprises, for example, at least one of the following materials: Ag, Al, Au, Cr, etc., as well as a sufficient thickness for this layer to be opaque and reflective.

[0085] In this second embodiment, the different layers of the light source 102 (electrodes and emitting layer(s)) are conformally deposited on the non-planar surfaces formed by the optical components 124. Compared to a planar light source 102 as previously described in relation to the first embodiment, the emitting surface of the light source 102 according to the second embodiment is larger, for a given footprint on the surface of the optical guiding element 104, which makes it possible to increase the amount of light sent into the optical guiding element 104. On the example of [Fig. 12], by making the optical components 124 so that they are arranged next to each other touching each other, the amount of light emitted can be about six times greater than in the case of a flat light source 102.

[0086] In the embodiment shown in [Fig. 12], the optical components 124 are concave in shape, which implies that the reflective surface formed by the reflective layer 120 is also concave.

[0087] In a variant shown in [Fig.13], the optical components 124 of the device 100 are formed from a layer of material 144 at least partially transparent to the light intended to be emitted by the light source 102, this layer of material 144 comprising hollows 146 arranged in line with the microneedles 108. Thus, these hollows 146 form convex surfaces such that the reflective surfaces formed by the reflective layer 120 opposite the microneedles 108 are also convex. Furthermore, in this variant, the optical guiding element 104 does not include the base 106 but only the microneedles 108. As in the previously described example, this variant allows for a larger emissive surface of the light source 102, for a given footprint on the surface of the optical guiding element 104, and therefore increases the amount of light sent into the optical guiding element 104.

[0088] The different variants previously described for the first embodiment can be applied to this second embodiment.

[0089] An example of a method for implementing device 100 according to the second embodiment is described below in relation to figures 14 to 17.

[0090] In this example, the optical components 124 are first produced by depositing at least one layer of transparent or semi-transparent material onto the substrate 126. This layer of material comprises, for example, a transparent or semi-transparent resin. Photolithography and development steps can then be carried out to form the material pads 138, for example, similar to those previously described for the first embodiment. The structure obtained at this stage of the process is shown in [Fig. 14].

[0091] A finishing step can then be implemented to form the optical components 124 (see [Fig. 15]).

[0092] The first electrode 128 is then produced, for example by deposition, on the optical components 124 as well as on parts of the substrate 126, between and next to the optical components 124. As in the first embodiment, the insulating portion 132 is then made (see [Fig. 16]).

[0093] The light source 102 is then completed by depositing the emissive layer(s) 134, and then the second electrode 136 (with, in the example described, the formation of the contact pad 130). The assembly is then covered with an encapsulation layer 148 which can be transparent or opaque (see [Fig. 17]).

[0094] The device 100 is then completed by transferring the substrate 126 onto an optical guiding element 104, for example similar to one of the examples previously described.

[0095] According to another embodiment described in connection with Figures 18 to 21, the device 100 can be made from an opaque substrate 150.

[0096] The opaque substrate 150 is first etched on one of its faces by creating grooves 152 forming convex surfaces (see [Fig. 18]). A first electrode is then deposited on the previously etched face of the substrate 150, and also in the grooves 152, so as to form the anode and the reflective surface. One or more emissive layers are then deposited on the first electrode. A second electrode is then deposited on the emissive layer(s), completing the formation of the light source 102. A transparent or semi-transparent encapsulating layer is finally deposited on the second electrode (see [Fig. 19]). The remaining volume of the grooves 152 that is not occupied by the layers deposited to form the light source 102 and by the encapsulating layer is filled with a material forming the optical components 124 (see [Fig. 20]).The assembly produced is then transferred, for example by gluing, onto a substrate comprising the optical guidance element(s) 104 (see [Fig.21]).

[0097] In all embodiments, the device 100 optimizes the injection of light into the optical guiding element 104 through the judicious use of the non-planar reflective surface 122, which, combined with a light source 102 emitting light both on the side of the optical guiding element 104 and on the side of the reflective surface 102, increases the amount of light sent to the optical guiding element 104, since the light emitted on the side of the reflective surface 122 is recovered and reflected towards the optical guiding element 104 thanks to the light reflection and focusing properties of the reflective surface 122.

[0098] Various embodiments and variations have been described. A person skilled in the art will understand that certain features of these various embodiments and variations could be combined, and other variations will become apparent to a person skilled in the art.

[0099] Finally, the practical implementation of the described embodiments and variants is within the reach of a person skilled in the art, based on the functional instructions provided. above. For example, the precise nature of the deposition and engraving steps implemented can be chosen based in particular on the material(s) to be deposited or engraved, as well as the thicknesses of the materials to be deposited or engraved.

Claims

Demands

1. Light-emitting device (100) comprising at least: - an optical guiding element (104); - a light source (102) at least partially transparent to at least one light intended to be emitted by the light source (102), and configured to emit the light at least on the side of a first face (116) disposed opposite the optical guiding element (104) and on the side of a second face (118) opposite the first face (116); - a reflective layer (120) disposed on the side of the second face (118) of the light source (102); - an optical component (124) disposed between the reflective layer (120) and the optical guiding element (104) and at least partially transparent to the light intended to be emitted by the light source (102);and in which the reflective layer (120) forms at least one reflective surface (122) conforming to a non-planar surface of the optical component (124) on which the reflective layer (120) is disposed.;

2. Light-emitting device (100) according to claim 1, wherein the light source (102) comprises at least one organic light-emitting diode.

3. Light-emitting device (100) according to claim 2, wherein the reflective layer (120) is one of the electrodes of the organic light-emitting diode.

4. Light-emitting device (100) according to any one of the preceding claims, wherein the reflective surface (122) comprises at least one concave or convex portion.

5. Light-emitting device (100) according to any one of the preceding claims, wherein the reflective surface (122) forms at least one spherical or conical or hyperbolic mirror.

6. Light-emitting device (100) according to any one of the preceding claims, wherein the reflective layer (120) comprises at least one metallic layer and / or at least one Bragg mirror.

7. Light-emitting device (100) according to any one of the preceding claims, further comprising at least one substrate (126) at least partially transparent to the light intended to be emitted by the light source (102) and disposed between the optical guiding element (104) and the light source (102).

8. Light-emitting device (100) according to any one of the preceding claims, wherein the optical guidance element (104) comprises at least one microneedle (108) at least partially transparent to the light intended to be emitted by the light source (102), or at least one waveguide.

9. Light-emitting device (100) according to claim 8, wherein the optical guidance element (102) comprises a base (106) at least partially transparent to the light intended to be emitted by the light source (102) and several microneedles (108) at least partially transparent to the light intended to be emitted by the light source (102) and each comprising a first end (112) integral with the base (106), the base (106) being disposed between the light source (102) and the microneedles (108).

10. Light-emitting device (100) according to claim 8, wherein the optical guidance element (104) comprises several microneedles (108) at least partially transparent to the light intended to be emitted by the light source (102), and wherein the optical component (124) comprises a layer of material (144) at least partially transparent to the light intended to be emitted by the light source (102), the layer of material (144) comprising hollows (146) aligned with the microneedles (108).

11. Light-emitting device (100) according to any one of claims 9 or 10, wherein the light source (102) comprises several distinct parts (140, 142) configured to emit lights of different wavelengths, each of said parts (140, 142) being arranged opposite at least one of the microneedles (108).

12. Light-emitting device (100) according to any one of claims 9 to 11, wherein the light source (102) is configured to emit a portion of the light between the microneedles (108).

13. Light-emitting device (100) according to any one of claims 9 to 12, wherein at least a portion of the surface reflective (122) is configured to reflect a portion of the light emitted from the side of the second face (118) of the light source (102) between the microneedles (108).

14. A method for making a light-emitting device (100), comprising at least: - making at least one optical guiding element (104); - making at least one light source (102) at least partially transparent to at least one light intended to be emitted by the light source (102), and configured to emit the light at least on the side of a first face (116) disposed opposite the optical guiding element (104) and on the side of a second face (118) opposite the first face (116); - making at least one reflective layer (120) disposed on the side of the second face (118) of the light source (102); - making at least one optical component (124) disposed between the reflective layer (120) and the optical guiding element (104) and at least partially transparent to the light intended to be emitted by the light source (102);and in which the reflective layer (120) is made such that it forms at least one reflective surface (122) conforming to a non-planar surface of the optical component (124) on which the reflective layer (120) is disposed.;

15. A method of embodiment according to claim 14, wherein: - the light source (102) and the reflective layer (120) are made on the optical guiding element (104), or - the light source (102) and the reflective layer (120) are made on a substrate (126) at least partially transparent to the light intended to be emitted by the light source (102), the substrate (126) being subsequently attached to the optical guiding element (104), or - the light source (102), the reflective layer (120) and the optical component (124) are made on a substrate (150) opaque to the light intended to be emitted by the light source (102), the optical component (124) being then attached to the optical guidance element (104).

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