Photonic sensor assembly, corresponding means for receiving a light signal, and corresponding optical system

Abstract

The present invention relates to a photonic sensor assembly (1) comprising: - photon receivers together forming a receiving surface (2); - an accommodating device (10) incorporating the photon receivers, comprising an electrically insulating support (7) and electrical connections that electrically connect the photon receivers to electrical connection terminals (5) arranged on the insulating support (7), wherein the electrical connections comprise metal wires (4) extending in a zone (Z) peripheral to the receiving surface (2); and - an electrically insulating covering material (8) embedding the metal wires (4) in the peripheral zone (Z), wherein the photonic sensor assembly (1) is characterised in that it comprises means for protecting the covering material (8), and wherein the protection means are capable of reflecting at least one component of light incident on the covering material (8).

Description

DESCRIPTION Title of the invention: Photonic sensor assembly, means for receiving a light signal and corresponding optical system

[0001] The present invention relates to the fields of electronics and optics, and concerns a photonic sensor assembly finding a particularly advantageous application in the automotive field.

[0002] In recent vehicles, light-emitting diode assemblies are commonly used to create external lighting devices such as signal lights. These diode assemblies allow energy savings while providing vehicles with light signatures specific to each brand, and are expected to be future means of vehicle communication with each other or with road infrastructure, thanks to optical communication technology such as VLC (for "Visible Light Communication") for example.

[0003] Indeed, the bandwidth of a white light-emitting diode with a side of one millimeter is approximately 2 MHz (Megahertz), and can therefore be sufficient to enable light communication between vehicles or between a vehicle and a road infrastructure. However, this bandwidth is not suitable for obstacle detection applications. Such an application is generally carried out optically in certain vehicles using LiDAR (Light Detection And Ranging) technology based on an infrared laser transmitter allowing analysis of the reflected signal over a bandwidth of the order of several tens of Megahertz, or even a few hundred Megahertz. LiDAR systems embedded in vehicles are nevertheless very expensive.

[0004] The inventors have, however, discovered that such an obstacle detection application is possible by using light-emitting diodes, which emit light in the visible spectrum, by increasing their bandwidth, either by equalization techniques or by using diodes smaller than 300 micrometers, or by combining these techniques. This application may require the use of a specific type of LED driver unit such as a high-speed driver or a laser driver. The LEDs used for this application may also be blue-light LEDs adapted to emit white light.

[0005] Thanks to this discovery, the inventors have made it possible to replace the expensive LiDAR technology in a vehicle with specific signaling devices based on light-emitting diodes, which perform, in addition to regulatory signaling functions, an obstacle detection function.

[0006] The inventors discovered that light-emitting diodes that natively emit turquoise light can alternatively be used for this application.

[0007] These signaling and obstacle detection devices include photonic receivers such as photodiodes, which receive light reflected on the obstacle to be detected, a part of this reflected light corresponding to the light emitted by the diodes, and emit output signals which, after processing, make it possible to detect the obstacle.

[0008] They also use optics to focus light from outside the vehicle onto one or more photonic sensors incorporating photonic receivers, in order to optimize their detection field.

[0009] However, in unusual conditions such as driving on a steeply rising slope, the inclination of the vehicle relative to an external light source such as the sun may result in the optics focusing light onto an area of ​​a sensor not intended for this purpose. However, the peripheral areas of the sensor contain materials that can overheat or even burn at 200°C, such as materials used to coat very fine metal electrical connection wires, such materials being, for example, made of silicone.

[0010] The present invention aims to remedy at least in part the aforementioned drawbacks by providing a photonic sensor assembly, reception means comprising this photonic sensor assembly and an optical system comprising these reception means, which do not suffer from alterations due to unusual focusing of light rays on non-receiving areas of the photonic sensor assembly.

[0011] To this end, the invention proposes a photonic sensor assembly comprising: - photonic receivers together forming a receiving surface, - a receiving device integrating the photonic receivers, the receiving device comprising an electrically insulating support and electrical connections electrically connecting at least part of the photonic receivers to electrical connection terminals arranged on the insulating support, the electrical connections comprising metal wires extending in a zone peripheral to the receiving surface, and - an electrically insulating covering material, embedding the metal wires in said peripheral zone, the photonic sensor assembly, also called a photonic sensor device, being characterized in that it comprises means for protecting the covering material, the protection means being at least partly capable of absorbing a blue or turquoise component of light incident on the covering material.

[0012] Thanks to the invention, the covering material is protected from possible deterioration due to light rays which would be focused on it, without using expensive means, such as the use of a covering material resistant to very high temperatures, and without giving up mechanical protection of the very fine metal wires of electrical connection. One could indeed consider leaving these metal wires in the open air, but they could be damaged by handling the sensor when mounting it on a vehicle.

[0013] According to the invention, the protection means are at least partly, preferably entirely, capable of absorbing a blue or turquoise component of the incident light. This characteristic is advantageous in the case where the optical sensor assembly according to the invention is used to receive a blue or turquoise component of incident light, respectively, such as, for example, in the obstacle detection application designed by the inventors and using blue light-emitting diodes, in particular adapted to emit white light, or in an application using native turquoise light-emitting diodes.

[0014] Indeed, in this case, the absorption of the blue component arriving at the means of protection prevents the reflection of this blue component on the means of protection. The reflected rays corresponding to such a reflection could otherwise reach the reception surface, and interfere, by optical crosstalk, with a blue light component of other rays arriving more directly on the reception surface. It is indeed important to receive on the reception surface a blue component of light arriving as directly as possible through reception means on the reception surface, after having been reflected on an obstacle outside the vehicle. Any blue component having undergone more reflections causes a time lag compared to this more direct reception, which distorts a subsequent calculation of the distance to the obstacle. The same technical effect is observed when the turquoise component is absorbed.

[0015] In one embodiment of the invention, the receiving surface is covered with a filter capable of allowing only a blue or turquoise component of light arriving on the receiving surface to pass through. This embodiment allows the receiving surface to receive only a blue component of the incident light. However, depending on the positioning of the optical filters, the covering material can receive all the components of an incident light, in particular non-blue components (respectively non-turquoise components).

[0016] According to an optional feature of the invention, the protection means are at least partly capable of reflecting a component of the incident light onto the covering material. This is particularly advantageous when the covering material can receive non-blue components of incident light, respectively non-turquoise components.

[0017] The protection means are preferably at least partly capable of absorbing a blue, respectively turquoise, component of the incident light and of reflecting the other components of the incident light. Thus, heating at the level of the covering material is limited to that caused by the blue component, which makes it possible to protect the covering material while avoiding parasitic reflections on the receiving surface. The part of the light other than the blue component can be reflected without risk of penalizing the signal detection within the light since even if the other components than the blue component are reflected directly or indirectly in the direction of the receiving surface, the latter is equipped with means for filtering this part of light other than the blue component.

[0018] The blue component has wavelengths between at least 420 and 460 nanometers. In other words, the covering material absorbs wavelengths between at least 420 and 460 nanometers.

[0019] In one embodiment of the invention, the protective means comprise the covering material, the latter being made of a material capable of absorbing the blue component of the incident light and reflecting the other components of the incident light. The covering material is for example made of silicone, tinted in the mass so as to absorb the blue component of light, the covering material then taking on a yellow color. Alternatively, the covering material is covered with a material having this property.

[0020] This embodiment makes it possible to avoid generating additional bulk due, for example, to a protective mask projecting a shadow on the covering material, and which would be added to the receiving means.

[0021] In another embodiment of the invention, the protection means further comprise at least one part reflecting all the components of the incident light, the part being arranged so as to reflect said components in directions oriented towards the outside of the photonic sensor assembly. In other words, the part is inclined so that the rays which are reflected on the part do not intersect the receiving surface of the photonic sensor assembly, and do not bounce off it. Since the light rays arrive on the covering material from the outside of the vehicle, it is sufficient, for example, for the part to be inclined from the receiving surface towards the inside of the vehicle. Thus, the covering material can be made of a material absorbing only blue light, and protected on inclined parts of the material by an aluminum part reflecting all the components of light incident on this part.This limits the heating of the covering material even more effectively, since only a part of the blue component of the light hitting the covering material is absorbed.

[0022] The invention also relates to means for receiving a high-frequency coded light signal, included at least in a predefined range of wavelengths between 420 and 460 nanometers, comprising a photonic sensor assembly according to the invention, and in which the protection means are capable of reflecting the components of the incident light of wavelengths greater than 460nm (nanometers).

[0023] The predefined wavelength range is a useful range in which the light signal is received for demodulation and corresponds, for example, to wavelengths for which the signal-to-noise ratio is most favorable, the light signal being able to be present also outside the predefined wavelength range. Optionally, the protective means are configured to reflect only light components with wavelengths greater than 460nm.

[0024] Preferably, the protection means are capable of reflecting the components of the incident light of wavelengths less than 420nm.

[0025] Alternatively, the receiving means further comprise a high-pass filter having a cut-off wavelength less than or equal to 420 nm, capable of filtering incident light arriving at the photonic sensor assembly. The high-pass filter allows only very little of the light components whose wavelengths are less than its cut-off wavelength to pass through. In particular, it makes it possible to prevent ultraviolet rays from passing through the receiving means and damaging the covering material.

[0026] Alternatively, the invention relates to means for receiving a high-frequency coded light signal, comprised at least in a predefined range of wavelengths comprised between 460 and 500 nanometers, preferably between 480 and 490 nanometers, comprising a photonic sensor assembly according to the invention, and in which the protection means are capable of reflecting the components of the incident light of wavelengths greater than 500nm, preferably greater than 490nm (nanometers), and / or the components of the incident light of wavelengths less than 460nm, preferably less than 480nm.

[0027] The invention finally relates to an optical system comprising: - light emission means comprising at least one photonic emitter capable of emitting a high-frequency coded light signal, the light signal being at least within a predefined range of wavelengths within the visible spectrum, preferably between 420 and 460nm, - means for receiving according to the invention a reflected light signal resulting from a reflection on an obstacle, of the light signal emitted by the photonic transmitter, - means for demodulating the light signal reflected received by the means of reception, - obstacle detection means comprising means for calculating a distance to the obstacle as a function of a demodulated signal provided by the demodulation means and the light signal emitted by the photonic transmitter.

[0028] The optical system according to the invention and the reception means according to the invention have advantages similar to those of the photonic sensor assembly according to the invention.

[0029] Other characteristics and advantages of the invention will become apparent from the following description on the one hand, and from several examples of embodiment given for informational and non-limiting purposes with reference to the attached schematic drawings on the other hand, in which:

[0030] [fig 1] represents an optical system according to a first embodiment of the invention, integrating an obstacle detection function,

[0031] [fig 2] represents a photonic sensor assembly of the optical system according to the first embodiment of the invention,

[0032] [fig 3] represents a photonic sensor assembly according to the invention, in a second embodiment of the invention, and

[0033] [fig 4] represents a photonic sensor assembly according to the invention, in a third embodiment of the invention.

[0034] A first embodiment of the invention is now described in relation to FIG. 1, in which an optical system S according to the invention provides obstacle detection and signaling and / or lighting functions. This optical system S is, in this exemplary embodiment of the invention, mounted on the front of a vehicle. The optical system S comprises, on the front of the vehicle, a plurality 120 of photonic emitters, for example in each optical unit of the vehicle, and a plurality of photonic receivers 20, also present in this example in each optical unit of the vehicle. The plurality 120 of photonic emitters comprises, for example, two blue light-emitting diodes 121, 122, adapted to emit white light.

[0035] The light-emitting diodes 121, 122 each comprise, for example, a layer of Galium-Indium nitride (InGaN) on which is deposited a light color conversion layer generally called phosphor in the bibliography. Thus, they are suitable for producing a light beam from a daytime running light.

[0036] The plurality 20 of photonic receivers is integrated into a photonic sensor assembly 1 according to the invention, and forms a matrix of photon avalanche photodiodes or SPAD photodiodes (from the English "Single-Photon Avalanche Diode") for increasing the reception gain. The photonic receivers 20 are therefore, in this exemplary embodiment of the invention, SPAD photodiodes. Of course, Figure 1 only includes two light-emitting diodes and two photodiodes for simplicity. Many more photodiodes are preferably used, and the optical units can use many more diodes to ensure both obstacle detection and produce a traffic light or a regulatory lighting beam.

[0037] The plurality 120 of light-emitting diodes is capable of emitting a high-frequency coded light signal s1 towards the exterior of the vehicle, and the plurality 20 of photodiodes is capable of receiving a corresponding reflected light signal s2, arriving from the exterior of the vehicle.

[0038] In order to form the high-frequency coded light signal s1, the optical system S comprises a source 31 of electrical signals in voltage square waves and a control unit 30, connected upstream of the light-emitting diodes 121, 122. To send the light signal s1, the source 31 provides a square wave signal whose width I of the square waves is, in an exemplary embodiment, approximately 10 ns (nanoseconds), the frequency of the signal being 50 MHz. The duty cycle of the signal is, in this example, less than or equal to 50%.

[0039] To enable the transmission of this signal having such a high frequency level, the control unit 30 comprises for example a pre-equalization stage, possibly associated with an amplifier stage. It is therefore an electronic device. Instead of or in addition, the light-emitting diodes 121, 122 are chosen in size less than 300 micrometers so as to naturally have a cut-off frequency greater than 50MHz.

[0040] The light signal s1 sent by the diodes 121, 122 encodes a specific sequence of "slots" or light peaks of width I of 10ns, this sequence repeating cyclically. In other words, the light signal s1 is modulated according to a specific data sequence, called modulating. The sequence of slots is defined so as to easily evaluate a time shift between its transmission and its reception as explained below.

[0041] The reflection of the light signal s1 on an obstacle 15 gives rise to the reflected light signal s2 of sufficient light power to be captured by the photodiodes 20.

[0042] Reception means 100 of the optical system S comprise, in addition to the photodiodes 20, a lens 14 focusing the light coming from outside the vehicle towards the photodiodes 20, and a blue light filter 9 making it possible to filter the incident light so as to allow only the blue component of this light to pass towards the photodiodes 20. The blue light emitted by the diodes 121, 122 generally has a light intensity lower than that of the illumination of the sun, but approaches it for wavelengths close to 460nm (nanometers). The filter 9 therefore makes it possible to transmit the reflected signal s2 to the photodiodes 20 only over a predefined range of wavelengths, for example between 420 and 460nm.

[0043] The modulation of the reflected signal s2 then makes it possible to distinguish it from external light pollution in the process of demodulation of this reflected light signal s2. The demodulation process makes it possible in particular to eliminate, in the reflected light signal s2, parasitic light signals emitted by other vehicles.

[0044] More precisely, the photodiodes 20 capture the blue components of the reflected light signal s2 and of the ambient light, for example sunlight, and provide an electrical signal to an electronic control device 13 which amplifies it and provides it to demodulation means 38. The electronic control device 13 is part of the reception means 100 of the optical system S present in the optical units of the vehicle. The demodulation means 38 are part of the optical system S but are for example remote in a computer of the vehicle.

[0045] The electronic control device 13 optionally comprises, in addition to an amplifier stage, a post-equalization stage. The photodiodes 20 being SPAD photodiodes, the electrical signal that they provide is equivalent to a count Nb of the photons received as a function of time t by each of the photodiodes 20. Thresholding means 34 adjust the detection level of these photodiodes so as to separate in the intensity of the light signal received by the photodiodes 20, the portion of light intensity due to sunlight. This thresholding corresponds to keeping in the count signal Nb as a function of time t, only the values ​​extending beyond a number of photons corresponding to the light intensity of the blue component of sunlight, which gives rise to a thresholded light signal s3. Such thresholding makes it possible to remove in the received electrical signal the component due to sunlight.Of course, what we call a thresholded light signal here is actually an electrical or digital signal corresponding to the thresholding of the received light signal s2.

[0046] The demodulation means 38 comprise the thresholding means 34 which are produced in software or analog manner from a non-thresholded electrical signal from the photodiodes 20.

[0047] The demodulation means 38 also comprise means 36 for correlating the thresholded light signal s3, once demodulated, with the light signal s1 sent by the diodes 121, 122. These correlation means 36 determine a time shift T between the demodulated thresholded light signal s3 and the sent light signal s1, and transmit this time shift T to obstacle detection means 40 of the optical system S, present in a computer of the vehicle. The obstacle detection means 40 convert this time shift T into a distance relative to the obstacle 15, and therefore make it possible to detect this obstacle. Described otherwise, the means demodulation means 38, from the reflected light signal s2 received by the photodiodes 20, are capable of providing the obstacle detection means 40 with at least one value representative of a time shift T between, on the one hand, the reflected light signal s2 and, on the other hand, the light signal emitted s1 by the diodes 121, 122.

[0048] Figure 2 shows in more detail the optical sensor assembly 1 according to the invention, used in the optical system S described previously.

[0049] The photonic sensor assembly 1 comprises an electronic chip 6 made up of different layers of semiconductors and metal deposits, the electronic chip 6 forming on one of its external faces, a receiving surface 2 comprising the receiving surfaces of a matrix of SPAD photodiodes 20 formed in the electronic chip 6.

[0050] The photonic sensor assembly 1 comprises a receiving device 10 for the electronic chip 6, this receiving device 10 comprising on the one hand an electrically insulating support 7, here a printed circuit board also called PCB (for the English “Printed Circuit Board”), for example made of epoxy resin, and on the other hand electrical connections making it possible to connect the cathodes of the photodiodes 20 to electrical connection terminals 5 which supply electrical signals to the electronic control device 13.

[0051] The electronic chip 6 is for example glued to the electrically insulating support 7 on the side opposite the receiving surface 2, which is bordered by cathode connection terminals 3. These cathode connection terminals 3 are each connected, by a gold metal wire 4, and at least one copper track passing through the electrically insulating support 7, to an electrical connection terminal 5, which is here a solder point arranged on a face of the electrically insulating support 7, opposite the face of the electrically insulating support 7 on which the electronic chip 6 is glued.

[0052] Of course, as an alternative, the 4 metal wires and the tracks on the PCB are made of another metal, and other types of connection terminals that solder balls are possible, on either side of the PCB.

[0053] The electrical connections, comprising the cathode connection terminals 3 and the metal wires 4, are arranged all around the receiving surface 2 in a peripheral zone Z of the photonic sensor assembly 1, all around the electronic chip 6.

[0054] The metal wires 4 being very thin and therefore easily tearable, a covering material 8 covers the entire peripheral zone Z on the electrically insulating support 7 or the electronic chip 6, thus covering all the cathode connection terminals 3 and the metal wires 4.

[0055] Since the receiving surface 2 is covered with the blue light filter 9, the covering material 8 is flush with the surface of the blue light filter 9 all around it.

[0056] The covering material 8 is for example made of silicone or epoxy, and colored so as to reflect the incident light with the exception of a blue component of light, in the range 420 to 460 nm, which is absorbed. For this, the covering material 8 is for example doped with a dye having the desired absorption spectrum, for example the dye is of the azo dye type, or the material is covered with a yellow-colored polymer.

[0057] Thus the light rays arriving on the covering material 8 are reflected with the exception of this blue component which is absorbed, and which cannot therefore interfere with the blue components of the same wavelengths of rays arriving directly on the reception surface 2 from the lens 14, through the filter 9. This reflection of the light rays on the covering material 8 is nevertheless sufficient to avoid degradation, by heating, of the covering material 8.

[0058] It should be noted that for simplicity, it is assumed that the filter 9 only lets through the same blue component of light as that absorbed by the covering material 8, hereinafter called “the” blue component.

[0059] A second embodiment of the invention will now be described in relation to Figure 3, in which many elements, being identical to the first embodiment of the invention, are referenced in the same way.

[0060] Unlike the first embodiment of the invention, in this second embodiment of the invention, the optical system according to the invention comprises a photonic sensor assembly 1 b comprising, in addition to the covering material 8, a metal part 11 reflecting all the components of incident light arriving on this metal part 11. The other characteristics of the photonic sensor assembly 1 b and of the corresponding optical system are identical to those of the photonic sensor assembly 1 and of the optical system S.

[0061] More specifically, the covering material 8 in the peripheral zone Z has an upper surface flush with the receiving surface 2 and forming a rectangular frame around it. The covering material 8 also has a surface orthogonal to this upper surface, this orthogonal surface flush with a lateral edge of the electrically insulating support 7.

[0062] The upper surface is connected to the orthogonal surface by a chamfer, on which the metal part 11 is arranged, for example made of aluminum. The metal part 11 is therefore inclined relative to the receiving surface 2, towards the outside thereof. It forms for example a rectangular frame of which each face is inclined, as on a truncated pyramid, the light rays arriving on the receiving surface 2 from the side opposite the base of this truncated pyramid.

[0063] In this configuration, only the blue component of an incident ray r1 arriving directly from the lens 14 on the filter 9 can pass through it to reach the receiving surface 2. An incident ray r4 arriving on the metal part 11 gives rise to a reflected ray r5 towards the outside of the photonic sensor assembly 1 b and therefore does not disturb the reception of the incident rays arriving directly on the receiving surface 2, even if the blue component of this incident ray r4 is also reflected.

[0064] An incident ray r2, arriving on the covering material 8 elsewhere than on the metal part 11, gives rise to a reflected ray r3 which can return towards the lens 14 and therefore by ricochet towards the receiving surface 2, but the covering material 8 having absorbed the blue light component of this reflected ray r3, the latter will not pass through the filter 9 and therefore will not disturb the good reception of the reflected light signal s2.

[0065] A third embodiment of the invention will now be described in relation to Figure 4, in which many elements, being identical to the first embodiment of the invention, are referenced in the same way.

[0066] Unlike the first embodiment of the invention, in this third embodiment of the invention, the receiving means 100c of an optical system according to the invention comprise a photonic sensor assembly 1c provided with the blue light filter 9, and a high-pass filter 12 upstream of the photonic sensor assembly 1c, between the lens 14 and the photonic sensor assembly 1c. The high-pass filter 12 has a cut-off wavelength of 420nm, in this exemplary embodiment of the invention.

[0067] Furthermore, in this third embodiment of the invention, a covering material 80 of the electrical connections of the photonic sensor assembly 1 c reflects only the components of the incident light of wavelengths greater than 460 nm. In other words, unlike the first embodiment of the invention, the covering material 80 absorbs not only the blue component of light but also ultraviolet rays. The covering material 80 is for example silicon doped with a dye so as to have a yellow or even orange color.

[0068] The other characteristics of the photonic sensor assembly 1 c are identical to those of the photonic sensor assembly 1 .

[0069] In this third embodiment of the invention, an incident ray r6, arriving on the reception surface 2 through the high-pass filter 12, comprises blue, green, yellow or red components but only the blue component of the incident ray r6 can arrive on the reception surface 2 thanks to the blue light filter 9.

[0070] The high-pass filter 12 also allows only the blue, green, yellow or red components of the incident light arriving on the covering material 80 to pass through. As a result, an incident ray r7 arriving on the covering material 80 gives rise to a reflected ray r8 which can return towards the lens 14 or the high-pass filter 12 and therefore by ricochet towards the reception surface 2, but the covering material 80 having absorbed the blue light component of this reflected ray r8, the latter will not pass through the filter 9 and therefore will not disturb the good reception of the reflected light signal s2.

[0071] Furthermore, in this third embodiment of the invention, the covering material 80 is capable of absorbing ultraviolet components of light, but thanks to the high-pass filter 12, these components do not reach the covering material 80 and therefore do not degrade it.

[0072] Symmetrically, an alternative embodiment consists of replacing the high-pass filter 12 with a low-pass filter, with a cut-off wavelength of 460nm for example, and using a covering material reflecting the light components of wavelengths less than 420nm and absorbing the other light components.

[0073] Of course, the invention is not limited to the examples which have just been described and numerous adjustments can be made to these examples without departing from the scope of the invention. The characteristics of the different embodiments or variants of the invention envisaged in this application can be combined to achieve the invention, to the extent that these embodiments or variants are not incompatible with each other.

[0074] Furthermore, the invention is not limited to the use of light-emitting diodes capable of emitting blue light, the high-frequency coded light signal being able to be decoded in another predefined range of wavelengths. In this case, the protective material is made so as to absorb only the wavelengths of this other predefined range, which may correspond to turquoise light as claimed, or even red for example. Any filtering means used are then adapted to this other predefined range of wavelengths at reception. The other components can then be reflected.

Claims

CLAIMS 1 - Photonic sensor assembly (1, 1b, 1c) comprising: - photonic receivers (20) together forming a receiving surface (2), - a receiving device (10) integrating the photonic receivers (20), the receiving device (10) comprising an electrically insulating support (7) and electrical connections electrically connecting at least a portion of the photonic receivers (20) to electrical connection terminals (5) arranged on the insulating support (7), the electrical connections comprising metal wires (4) extending in a peripheral zone (Z) to the receiving surface (2), and - an electrically insulating covering material (8, 80), embedding the metal wires (4) in said peripheral zone (Z), the photonic sensor assembly (1, 1 b, 1 c) being characterized in that it comprises means for protecting the covering material (8, 80), the protection means are at least partly capable of absorbing a blue or turquoise component of the light incident on the covering material (8, 80). 2- Photonic sensor assembly (1, 1 b, 1 c) according to claim 1, in which the protection means are capable of reflecting at least one component of the incident light onto the covering material (8, 80). 3- Photonic sensor assembly (1, 1 b, 1 c) according to claim 1 or 2, in which the receiving surface (2) is covered with a filter (9) capable of allowing only the blue component, or, respectively, the turquoise component, of light arriving on the receiving surface to pass. 4- Photonic sensor assembly (1, 1 b) according to any one of claims 1 to 3, in which the protection means are at least partly capable of absorbing the blue component, or, respectively, the turquoise component, of the incident light and of reflecting the other components of the incident light. 5- Photonic sensor assembly (1, 1 b, 1 c) according to any one of claims 2 to 4, in which the blue component is of lengths wavelengths of at least 420 to 460 nanometers, or, respectively, wherein the turquoise component is of wavelengths of at least 480 to 500 nanometers. 6- Photonic sensor assembly (1, 1 b) according to claim 5, in which the protection means comprise the covering material (8), the latter being made of a material capable of absorbing the blue component of the incident light, or, respectively, the turquoise component of the incident light, and of reflecting the other components of the incident light. 7- Photonic sensor assembly (1 b) according to any one of claims 1 to 6, in which the protection means further comprise at least one part (11) reflecting all the components of the incident light, the part (11) being arranged so as to reflect said components in directions oriented towards the outside of the photonic sensor assembly (1). 8- Means for receiving (100, 100c) a high-frequency coded light signal, included at least in a predefined range of wavelengths between 420 and 460 nanometers, comprising a photonic sensor assembly (1 c) according to any one of claims 1 to 3, in which the protection means are at least partly capable of absorbing a blue component, and in which the protection means are capable of reflecting the components of the incident light of wavelengths greater than 460 nm. 9- Means for receiving (100, 100c) a high-frequency coded light signal according to claim 8, in which the protection means are capable of reflecting the components of the incident light of wavelengths less than 420nm. 10- Means for receiving (100c) a high-frequency coded light signal according to claim 8, further comprising a high-pass filter (12) having a cut-off wavelength less than or equal to 420nm, capable of filtering incident light arriving at the photonic sensor assembly. 11 - Optical system (S) comprising: - light emitting means comprising at least one photonic emitter (121, 122) capable of emitting a high-frequency coded light signal (s1), the light signal (s1) being at least included in a predefined range of wavelengths included in the visible spectrum - reception means (100, 100c) according to any one of claims 8 to 10, of a reflected light signal (s2) originating from a reflection on an obstacle (15), of the light signal (s1) emitted by the photonic transmitter (121, 122), - demodulation means (39) of the reflected light signal (s2) received by the reception means (100, 100c), and - obstacle detection means (40) comprising means for calculating a distance to the obstacle (15) as a function of a demodulated signal supplied by the demodulation means (39) and of the light signal emitted (s1) by the photonic transmitter (121, 122).

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