Protection unit and detection assembly for motor vehicle

Abstract

The invention relates to a protection unit (1) for a device (21) and to a detection assembly (2) associated with a device (21) emitting or capturing radiation (23) passing through a region of interest of an optical surface (10) of the protection unit (1). The protection unit (1) further comprises at least one wave transducer (13) configured to generate acoustic waves on or in the optical surface (10) in order to clean the optical area of interest (12). According to the invention, the protection unit (1) further comprises a perforated surface (30) positioned facing the optical surface (10), the perforated surface (30) comprising a solid portion (31) and at least one aperture (32) through which radiation (23) emitted and / or captured by the device (21) can pass.

Description

[0001] The technical background of the present invention is sensors, in particular devices for cleaning optical surfaces, which sensors perform their measurements through such optical surfaces. More specifically, the present invention relates to a protection unit allowing such cleaning, a detection assembly including such protection unit, and a motor vehicle.

[0002] Generally speaking, the present invention relates to a protection unit employing a wave transducer which allows cleaning off an object in contact with an optical surface by means of ultrasonic waves. Herein, "cleaning" means that the wave transducer is configured to remove the object in contact with the optical surface such that after the cleaning operation, the optical surface is free of said object.

[0003] The present invention has applications in many fields. As a non-limiting example, the present invention aims to eliminate the effects associated with the accumulation of objects (such as in particular raindrops, frost or snow) on an optical surface.

[0004] In order to remove these objects from the surface, when these objects are in a liquid state and present on the optical surface in the form of droplets, it is known to rotate the droplets so as to be able to remove them from the surface. A known drawback of this technique is that it is not suitable for surfaces larger than a few square centimeters.

[0005] It is also known to use an electric field to control the hydrophobicity of a surface, as described for example in KR 2018 0086173A1. This technique is known by the acronym EWOD, meaning "Electro Wetting On Devices", and consists of applying a potential difference between two electrodes so as to electrically bias the surface from which it is desired to remove the droplets and to change its wetting properties. By controlling the position of the bias, the droplets can then be moved. A known drawback of this technique is that it can only be implemented with specific materials and requires the electrodes to be positioned particularly precisely over the entire area where it is desired to control the wetting properties, which makes its industrialization, large-scale production and integration into products intended for the automotive industry, for example, complex or problematic.

[0006] Furthermore, it is of course also known to use a windshield wiper on the windshield of a motor vehicle. However, a drawback of this proven technique is that it blocks the field of vision visible to the driver. In addition, whenever the windshield wiper passes, the windshield wiper spreads the fatty particles deposited on the surface of the windshield. Moreover, the accessories of the windshield wiper must be replaced regularly as they wear out during use. Finally, this technique cannot be used or is hardly applicable for cleaning sensors used on motor vehicles, such as lidar, proximity sensors or cameras.

[0007] For cleaning a windshield or a sensor used on a motor vehicle, such as a lidar, a proximity sensor or a camera, the following cleaning methods are known, which make it possible to remove the liquid accumulated on the optical surface of the sensor by generating ultrasonic waves and making them propagate in or on the optical surface. In particular, document WO 2012 / 095643A1 is known, which describes a method for removing raindrops by means of ultrasonic vaporization. The amplitude and frequency of the vibration are selected such that the raindrops falling on the windshield are vaporized as soon as they enter the vibration zone of the surface of the windshield. However, in order to obtain the vaporization of droplets, pools or films, the vibration zone requires a very high power level of vibration, which limits their practical implementation, especially in the context of the development of autonomous devices. In addition, it is well known that the energy level required for vaporization is greater than the energy level required to move droplets on a medium.

[0008] The techniques presented above all have the disadvantage of being related to their integration into a smaller surface or close to a restricted surface, or even integrated into a surface located behind a perforated surface, which makes them more difficult to access and clean.

[0009] One object of the present invention is to propose a new protection unit in order to solve at least most of the foregoing problems and also provide other advantages.

[0010] Another object of the present invention is to contribute to the cleaning of an optical surface located behind a perforated surface.

[0011] Another object of the present invention is to allow such cleaning while masking the wave transducer and making it less noticeable.

[0012] According to a first aspect of the present invention, at least one of the above objects is achieved by a unit for protecting an optical surface, the protection unit being intended to be associated with a device configured to sense and / or emit radiation passing through a region of interest of the optical surface, the protection unit comprising:

[0013] - the optical surface;

[0014] - a perforated surface, the perforated surface being fixed to the optical surface and placed facing the optical surface, the perforated surface comprising a solid part and at least one hole formed in the solid part;

[0015] - at least one wave transducer, the at least one wave transducer being mechanically coupled to the optical surface and configured to generate waves that propagate through the optical surface and propagate in the direction of and / or into the region of interest of the optical surface, the waves generated by the at least one wave transducer being ultrasonic waves.

[0016] In the context of the present invention, a protection unit allows a device intended to be located behind an optical surface to be protected so as to prevent dust, raindrops or any particles from reaching the device and interfering with its correct operation. In the context of the present invention, the protection unit can be implemented with any device of a motor vehicle and can take any form.

[0017] In the context of the present invention, a perforated surface is a mechanical component placed in front of an optical surface relative to the average propagation direction of waves emitted and / or received by the device with which the protection unit is intended to cooperate. The perforated surface can be formed by one or more parts. The perforated surface is fixed to the protection unit, and thus, there is no mobility between the perforated surface and the optical surface. As a non-limiting example, the perforated surface can be a grid, a radiator grille, a metal sheet with at least one hole, or a bumper component with at least one hole. According to a particularly advantageous embodiment, the perforated surface includes the logo of a motor vehicle, and the protection unit according to the first aspect of the present invention is intended to be mounted on the logo.

[0018] In the context of the present invention, the logo takes the form of a stamped component or a badge, the shape and size of which represent the trademark of the motor vehicle or the model of the motor vehicle. In the context of the present invention, the logo is preferably a logo embedded on the front of the motor vehicle, in particular on the radiator grille of the front.

[0019] Thus, the protection unit according to the first aspect of the present invention enables the logo of the motor vehicle and the presence of the device located behind the logo to be combined in an optimal manner, and thus, the protection unit enables a particularly advantageous configuration to be provided for the at least one wave transducer so as to allow optimal operation.

[0020] In the context of the present invention, the solid parts of the perforated surface form opaque parts, in particular parts opaque to the radiation emitted and / or sensed by the device intended to be located behind. The solid parts are, for example, parts formed of a material, while at least one hole of the perforated surface forms a part without material.

[0021] As a non-limiting example, the perforated surface can be formed of any material, in particular of metal or plastic.

[0022] In the context of the present invention, at least one wave transducer is an electronic chip configured to be able to generate the waves in question. As a non-limiting example, at least one wave transducer (the expressions "transducer of waves" and "wave transducer" are interchangeable in this text) is of the type with an electro-mechanical comb, which when electrically biased allows waves to be generated such that the waves propagate in or on the optical surface, in the direction of the optical region of interest and / or propagate into the optical region of interest.

[0023] The wave generated by at least one wave transducer advantageously has a fundamental frequency between 0.1 MHz and 1000 MHz, preferably between 15 MHz and 30 MHz, for example equal to 20 MHz. Additionally or alternatively, the wave generated by at least one wave transducer advantageously has a surface amplitude or deformation amplitude between 1 nanometer and 500 nanometers.

[0024] In the context of the present invention, the wave generated by at least one wave transducer is an ultrasonic wave. More particularly, the wave thus generated is one of the following types:

[0025] - Surface ultrasonic wave, i.e., Rayleigh wave, at this time the thickness of the optical surface is greater than the wavelength of the surface ultrasonic wave. This surface wave propagates at the surface of the optical surface. Rayleigh wave is preferred because the largest proportion of the wave energy is concentrated on the top of the optical surface where the wave propagates, and can be transmitted to an object placed on the optical surface, such as a raindrop. In this case, the surface wave propagates on the optical surface acoustically coupled to at least one transducer, or even preferably fastened to at least one transducer;

[0026] - Ultrasonic body wave or Lamb wave, at this time the thickness of the optical surface is less than the wavelength of the ultrasonic body wave. This body wave propagates through the optical surface and enables the entire optical surface thus traversed by the body wave to "vibrate", i.e., the two optical surfaces that are positioned relative to each other and form the optical surface.

[0027] Therefore, the protection unit according to the present invention enables the optical surface to be efficiently cleaned by means of the propagation of the wave in the optical surface, such that an object (such as a raindrop) in contact with the optical surface is accelerated by the wave generated by each of at least one wave transducer, with or without the aid of external forces (such as gravity or aerodynamic force).

[0028] In the context of the present invention, the optical surface can be of any type and can perform any function related to one or more devices that are intended to emit or sense radiation passing through said optical surface and are positioned facing said optical surface. As a non-limiting example, the optical surface can be an optical lens that is part of one or more devices (through which the radiation passes) or even a protective surface positioned facing one or more optical lenses of one or more devices. Generally, the optical surface is formed of a material that allows the propagation of ultrasonic waves emitted by the transducer, whether these ultrasonic waves are surface waves or body waves. As a non-limiting example and according to a preferred embodiment of the present invention, the optical surface is formed of glass in order to facilitate the propagation of such waves. Additionally, the optical surface or at least the optically relevant region is formed of a material that is transparent to the radiation that is intended to be emitted or sensed by the devices associated with the protection unit according to the first aspect of the present invention. In particular, the radiation emitted or sensed by the devices propagates in the optical surface or at least in its optically relevant region by transmission and / or refraction and / or scattering in such a way that most of the radiation from the first side of the optical surface (or at least from its optically relevant region) appears on the other side of the optical surface, i.e., on the second side of the optical surface (or at least in its optically relevant region).

[0029] In the context of the present invention, the optically relevant region corresponds to the part of the optical surface that faces the devices that are intended to be positioned in association with the protection unit and said optical surface. The optically relevant region corresponds to a part of the optical surface in which the radiation emitted or sensed by the devices passes through the optical surface.

[0030] In the context of the present invention, the devices that are intended to be associated with the optical surface of the protection unit are configured to sense and / or emit radiation. For this purpose, the device includes a radiation sensor and / or a transmitter. The radiation is, for example, electromagnetic radiation whose spectrum has wavelengths that can be located in the visible spectrum and / or in the invisible spectrum. As a non-limiting example, the device is preferably selected from optical remote sensing devices such as lidar, cameras, radars, infrared sensors, and ultrasonic rangefinders.

[0031] In particular, in the context of the present invention, the integration of such devices behind the logo is subject to particular limitations and constraints. Additionally, the presence of at least one hole in the perforated surface tends to cause the accumulation of particles on the optical surface positioned facing said at least one hole, thereby subsequently making the operation of the devices that are intended to be located behind it more difficult and less desirable.

[0032] Thus, the protection unit according to the first aspect of the present invention enables the correct operation of the device with which it is intended to be associated to be promoted, since the optical region of interest of the optical surface through which the device senses or emits radiation is cleaned by the wave transducer. Thus, this advantageous configuration enables the interference between the objects already present on the optical surface in the optical region of interest and the radiation passing through the optical region of interest to be reduced.

[0033] The protection unit according to the first aspect of the present invention advantageously comprises at least one of the following improvements, the technical features forming these improvements being able to be considered individually or in combination:

[0034] - At least one wave transducer is positioned facing the solid part of the perforated surface. This advantageous configuration enables at least one wave transducer to be masked behind the solid part of the perforated surface. This also enables the parts of the optical surface facing at least one hole of the perforated surface to be kept uncluttered, which parts are preferably reserved for future alignment with the device with which the protection unit is intended to cooperate. More particularly, the alignment between at least one wave transducer and the solid part of the perforated surface is observed with respect to an axis perpendicular to the optical surface located opposite.

[0035] - At least one wave transducer is firmly fastened to the optical surface by any means, in particular by adhesive bonding.

[0036] - At least one wave transducer is intended to be electrically connected to an electrical device by at least one wire connected to the at least one wave transducer, the at least one wire being laid facing the solid part. The electrical device to which at least one wave transducer is intended to be electrically connected is, for example, a power supply or a control unit for controlling at least one transducer. Thus, in the context of the present invention, the at least one wire connecting at least one wave transducer to the electrical device is a power wire for supplying the power for biasing at least one wave transducer and / or a control wire for transmitting the electrical signals for controlling the operation of at least one wave transducer. The at least one wire preferably extends along and against the optical surface. In the context of the present invention, the at least one wire (with respect to the part of it located facing the perforated surface) is always laid facing the solid part of the perforated surface in order to prevent the at least one wire from being seen. More particularly, the alignment between the at least one wire and the solid part of the perforated surface is observed with respect to an axis perpendicular to the optical surface located opposite.

[0037] - In the context of the present invention, the at least one wire can be a cable which comprises one or more wires braided together and / or placed inside an insulating sheath. Alternatively, each wire of the at least one wire can comprise a conductive element housed inside an insulating sheath;

[0038] - At least one electrical wire is firmly fastened to the optical surface. This advantageous configuration makes it possible to prevent at least one electrical wire from moving during the use of the protection unit according to the first aspect of the invention, or even from breaking or being damaged during the use of the protection unit. In the context of the present invention, at least one electrical wire can be firmly fastened to the optical surface by any means;

[0039] - Preferably, at least one electrical wire is adhesively bonded to the optical surface. In the context of the present invention, at least one electrical wire can be adhesively bonded to the optical surface along the entire length of the at least one electrical wire. Alternatively, at least one electrical wire can be adhesively bonded to the optical surface discontinuously or even only at its terminals;

[0040] - According to a first embodiment, at least one wave transducer is located on the first side, called the inner face, of the optical surface, which first face is intended to be on the side of the device with which the protection unit is intended to cooperate, opposite the second face, called the outer face, of the optical surface which is oriented towards the perforated surface. The waves generated by at least one wave transducer are body waves. In other words, at least one device and at least one wave transducer are located on the same side of the optical surface with respect to the propagation direction of the radiation emitted by at least one device. Thus, this advantageous configuration makes it possible to place at least one transducer on the side of at least one device depending on the available space. Thus, at least one wave transducer is advantageously configured to generate body waves or Lamb waves in the direction of the optical region of interest and / or into the optical region of interest and through the optical surface, such that they reach the face of the optical surface on the side of the perforated surface which is splashed by raindrops and / or particles and which must therefore be cleaned;

[0041] In the first embodiment, the wavelength of the waves generated by at least one wave transducer is greater than or equal to twice the thickness of the optical surface measured in the optical region of interest. This advantageous configuration makes it possible to better dimension both the thickness of the optical surface and the wavelength of the waves generated by at least one transducer in order to achieve optimal operation and optimal cleaning of the optical surface oriented towards the perforated surface;

[0042] - According to a second embodiment, at least one wave transducer is located on the outer face of the optical surface which is oriented towards the perforated surface. The waves generated by at least one wave transducer are Rayleigh waves. In other words, the device and at least one wave transducer are located on opposite sides of the optical surface with respect to the propagation direction of the radiation emitted by at least one device. Thus, this advantageous configuration makes it possible to place at least one transducer on the side of the optical surface which is splashed by raindrops and / or particles and which must therefore be cleaned. Thus, in this first configuration, at least one wave transducer is advantageously configured to generate surface waves in the direction of the optical region of interest and / or into the optical region of interest;

[0043] - In this second embodiment, the wavelength of the wave generated by at least one wave transducer is less than or equal to one fifth of the thickness of the optical surface measured in the optical region of interest. This advantageous configuration enables better determination of the dimensions of both the thickness of the optical surface and the wavelength of the wave generated by at least one transducer, in order to achieve optimal operation and optimal cleaning of the optical surface positioned facing the perforated surface;

[0044] - The protection unit has a non-zero gap between the optical surface and the perforated surface, such that at least one wave transducer is not mechanically coupled to the perforated surface. In other words, the perforated surface is located at a distance from at least one wave transducer so as to allow mechanical separation between at least one wave transducer and the perforated surface. This configuration enables avoidance of any interference between at least one transducer and the perforated surface and promotes the propagation of the wave generated by at least one wave transducer in the optical surface;

[0045] - The dimension of the gap measured in a direction perpendicular to the optical surface is greater than 100 μm;

[0046] - Advantageously, the protection unit includes a cover member covering at least one wave transducer. Thus, the cover member enables prevention of water and / or objects from penetrating into at least one wave transducer and preventing premature and undesired failures resulting therefrom. The cover member is firmly fastened to at least one wave transducer or firmly fastened to the optical surface;

[0047] - The optical surface and the perforated surface are fixed to each other. In other words, the optical surface and the perforated surface are held immovably relative to each other;

[0048] - According to a first variant embodiment, the perforated surface is firmly fastened to the holder by a fastening tab extending through a window formed in the optical surface. In the context of the present invention, the optical surface is located at an intermediate position between the holder and the perforated surface with respect to the average propagation direction of the radiation emitted and / or sensed by the device intended to cooperate with the protection unit. In other words, the holder is located on one side (referred to as the inner surface) of the first surface of the optical surface, which first surface is on the side of the device with which the protection unit is intended to cooperate, while the perforated surface is then located near the second surface (referred to as the outer surface) of the optical surface facing the perforated surface and opposite to the inner surface. In other words, the holder and the perforated surface are located on both sides of the optical surface with respect to the propagation direction of the radiation emitted by at least one device;

[0049] - According to a second variant embodiment, the perforated surface is firmly fastened to the optical surface by a fastening tab fixed to the optical surface. In this variant embodiment, the perforated surface is directly linked to the optical surface without involving the intermediate member forming the holder in the above first variant embodiment;

[0050] - In any of the variant embodiments, the fastening tabs may take any form and are configured to allow mechanical coupling to the holders or optical surfaces to which they are attached;

[0051] - In any of the variant embodiments, at least one wave transducer is placed in an intermediate position between the fastening tab and the optical region of interest. In other words, in the plane formed by the optical surface, at least one transducer is located between, on the one hand, the region of the optical surface through which or to which the fastening tab passes and, on the other hand, the optical region of interest. Thus, the waves generated by at least one wave transducer reach directly the optical region of interest without passing through the region of the optical surface where the fastening tab is located. This advantageous configuration makes it possible to ensure good operation of at least one wave transducer and ultimately good cleaning in the optical region of interest of the optical surface.

[0052] According to a second aspect of the invention, there is provided a detection assembly comprising:

[0053] - A protection unit according to the first aspect of the invention or according to any of its improvements;

[0054] - At least one device configured to sense and / or emit radiation passing through the optical region of interest of the optical surface and through at least one hole of the perforated surface.

[0055] In the context of the invention, at least one device is positioned facing the optical surface at a distance from or against the optical surface such that the radiation emitted or sensed by said at least one device passes through the optical region of interest of the optical surface. Thus, the optical surface of the protection unit forms a protection surface for at least one device.

[0056] Furthermore, in the context of the invention, at least one device is positioned facing at least one hole of the perforated surface so as to allow the radiation emitted and / or sensed by said at least one device to pass through said at least one hole.

[0057] The detection assembly according to the second aspect of the invention advantageously comprises at least one of the following improvements, the technical features forming these improvements being able to be considered individually or in combination:

[0058] - At least one device is fixed to the optical surface. In this variant embodiment, the at least one device and the optical surface are held stationary relative to each other. According to the first variant embodiment, the at least one device is firmly and directly fastened to the optical surface, and the at least one device includes fastening members that cooperate with the optical surface. As a non-limiting example, the optical surface can be adhesively bonded to the front portion of the at least one device, or the at least one device can be screwed or snap-fastened to the optical surface. According to the second variant embodiment, the at least one device is firmly fastened to a holder, and the optical surface is also firmly fastened to the holder. In this second variant embodiment, the optical surface and the at least one device include fastening members, such as fastening screws or fastening clips, that cooperate with the holder;

[0059] - According to the first embodiment, at least one wave transducer is located on a first side of the optical surface opposite to a second side where the at least one device is located. In other words, the at least one device and the at least one wave transducer are located on opposite sides of the optical surface with respect to the propagation direction of the radiation emitted by the at least one device. Thus, this advantageous configuration enables the at least one transducer to be placed on the side of the optical surface that is splashed by raindrops and / or particles and thus has to be cleaned. Therefore, in this first configuration, the at least one wave transducer is advantageously configured to generate surface waves in the direction of and / or into the optical region of interest;

[0060] - According to the second embodiment, the at least one transducer and the at least one device are located on the same side of the optical surface. In other words, the at least one device and the at least one wave transducer are located on the same side of the optical surface with respect to the propagation direction of the radiation emitted by the at least one device. Thus, this advantageous configuration enables the at least one transducer to be placed on the side of the at least one device depending on the available space. Therefore, in this second configuration, the at least one wave transducer is advantageously configured to generate body waves in the direction of and / or into the optical region of interest and through the optical surface such that they reach the side of the optical surface that is splashed by raindrops and / or particles and thus has to be cleaned.

[0061] According to a third aspect of the present invention, a motor vehicle is proposed, which motor vehicle includes a detection assembly according to any one of the second aspect of the present invention or according to an improvement thereof.

[0062] Various embodiments of the present invention are provided, which combine the various alternative features described herein in all possible combinations.

[0063] On the one hand by the following description, and on the other hand by means of a plurality of exemplary embodiments given non-limitingly and indicatively with reference to the attached schematic drawings, other features and advantages of the present invention will become clearer, in the drawings:

[0064] ​Figure 1 shows a schematic electrical sectional view of a first exemplary embodiment of a detection assembly according to a second aspect of the present invention and including a protection unit according to a first aspect of the present invention;

[0065] Figure 2 shows a schematic electrical sectional view of a second exemplary embodiment of a detection assembly according to a second aspect of the present invention and including a protection unit according to a first aspect of the present invention;

[0066] Figure 3 shows a schematic electrical front view of a third exemplary embodiment of a detection assembly according to a second aspect of the present invention and including a protection unit according to a first aspect of the present invention;

[0067] Figure 4 shows a schematic electrical front view of a fourth exemplary embodiment of a detection assembly according to a second aspect of the present invention and including a protection unit according to a first aspect of the present invention.

[0068] Of course, the features, variations, and various embodiments of the present invention can be combined with each other in various combinations, as long as they are compatible with each other or not mutually exclusive. In particular, it will be possible to conceive of variations of the present invention that include only the features described below in isolation from other features, provided that such a selection of features is sufficient to provide a technical advantage or to distinguish the present invention from the prior art.

[0069] In particular, if nothing from a technical perspective prevents the combination of all the described variations and all the embodiments, they can be combined with each other.

[0070] In the drawings, elements common to multiple drawings retain the same reference numerals.

[0071] Referring Figures 1 to 4 , the present invention relates to a unit 1 for protecting an optical surface 10, the protection unit being intended to be associated with a device 21 configured to sense and / or emit radiation 23 passing through a region of interest 12 of the optical surface 10, the protection unit 1 comprising:

[0072] - an optical surface 10;

[0073] - a perforated surface 30, the perforated surface being fixed to the optical surface 10 and placed facing the optical surface 10, the perforated surface 30 including a solid portion 31 and at least one hole 32 formed in the solid portion 31;

[0074] - at least one wave W transducer 13, the at least one wave W transducer being mechanically coupled to the optical surface 10 and configured to generate a wave W that propagates through the optical surface 10 and propagates in the direction of and / or into the region of interest 12.​​​

[0075] The perforated surface 30 is a mechanical component placed in front of the optical surface 10 with respect to the average propagation direction of the wave W emitted and / or received by the device 21 with which the protection unit 1 is intended to cooperate. The perforated surface 30 can be formed by one or more parts. The perforated surface 30 is fixed to the protection unit 1, so there is no mobility between the perforated surface 30 and the optical surface 10. As can be seen in Figure 3 and Figure 4 the perforated surface 30 includes the logo of a motor vehicle to which the protection unit 1 is mechanically coupled.

[0076] The solid parts 31 of the perforated surface 30 form parts opaque to the radiation 23 emitted and / or sensed by the device 21 intended to be located behind the optical surface 10. The solid parts 31 are, for example, parts formed of a material, while at least one hole 32 of the perforated surface 30 forms a part without material.

[0077] As can be seen in Figure 1 and Figure 2 there is a non-zero gap between the optical surface 10 and the perforated surface 30 such that the wave W transducer 13 is not mechanically coupled to the perforated surface 30. In other words, the perforated surface 30 is located at a certain distance from the wave W transducer 13 to allow for mechanical separation between the wave W transducer 13 and the perforated surface 30.

[0078] In the exemplary embodiment shown in Figure 1 the perforated surface 30 is firmly fastened to the optical surface 10 by a fastening tab 16 fixed to the optical surface 10.

[0079] In the exemplary embodiment shown in Figure 2 the perforated surface 30 is firmly fastened to the holder 17 by a fastening tab 16 extending through a window formed in the optical surface 10. Thus, the holder 17 is located on the side of the first face 11A (referred to as the inner face) of the optical surface 10, which is the side facing the device 21 with which the protection unit 1 is intended to cooperate, and the perforated surface 30 is then located near the second face 11B (referred to as the outer face) of the optical surface 10 facing the perforated surface 30 and opposite to the inner face. In other words, the holder 17 and the perforated surface 30 are located on both sides of the optical surface 10 with respect to the propagation direction of the radiation 23 emitted by the device 21.

[0080] In order not to impede the propagation of the wave W on or through the optical surface 10, and as Figures 1 to 3As shown, the wave W transducer 13 is placed at an intermediate position between the fastening piece 16 and the optical region of interest 12. In other words, on the second surface 11B of the optical surface 10, the transducer 13 is located between, on the one hand, the region of the optical surface 10 through which or to which the fastening piece 16 passes or is fastened and, on the other hand, the optical region of interest 12 formed by the region of the optical surface 10 through which the radiation 23 emitted and / or sensed by the device 21 passes through the optical surface 10.

[0081] In Figures 1 to 4 the exemplary embodiment shown, a detection assembly 2 is also shown, which detection assembly includes:

[0082] - a protection unit 1;

[0083] - at least one device 21 configured to sense and / or emit radiation 23 passing through the optical region of interest 12 of the optical surface 10 and through at least one hole 32 of the perforated surface 30.

[0084] Thus, as can be seen in Figure 3 and Figure 4 each device 21 cooperating with the protection unit 1 and its optical surface 10 is positioned facing at least one hole 32 of the perforated surface 30 so as to be able to sense and / or emit radiation 23 passing through the optical surface 10 and the perforated surface 30 efficiently at the same time.

[0085] Each device 21 is positioned facing the optical surface 10 at a distance from or against the optical surface 10 such that the radiation 23 emitted or sensed by the at least one device 21 passes through the optical region of interest 12 of the optical surface 10.

[0086] Each device 21 is fixed to the optical surface 10 such that each device 21 and the optical surface 10 remain stationary relative to each other.

[0087] In Figure 1 the example shown, the device 21 is directly and firmly fastened to the optical surface 10, for example by adhesive bonding, screwing or snap fastening.

[0088] In Figure 2 the example shown, the device 21 is firmly fastened to a holder 17 to which the optical surface 10 is also firmly fastened.

[0089] One or more transducers 13 associated with the optical surface 10 are acoustically coupled to the optical surface 10 (and preferably mechanically coupled to the optical surface) so as to be able to generate a wave W propagating on the second face 11B of the optical surface 10 (in particular when the wave W transducer 13 is located on or on this side of the second face 11B) or a wave propagating through the optical surface 10 (in particular when the wave W transducer 13 is located on or on this side of the first face 11A of the optical surface 10).

[0090] In Figure 4 the example shown, the wave W transducer 13 is positioned facing the solid part 31 of the perforated surface 30 so as to hide the wave transducer behind the solid part 31 of the perforated surface 30. In this exemplary embodiment, the wire 14 connected to each wave W transducer 13 is laid facing the solid part 31 of the perforated surface 30 so that the wire is not visible when looking at the perforated surface 30 from the front, as Figure 4 shown. Thus, the wire 14 extends in the direction of the lateral edge of the optical surface 10, behind and facing the solid part 31 of the perforated surface 30.

[0091] In Figure 3 the example shown, the wave W transducer 13 is misaligned with respect to the perforated surface 30 and / or with respect to its solid part 31. More particularly, in this exemplary embodiment, the wave W transducer 13 is located on top of the perforated surface 30. In this exemplary embodiment, the wire 14 connected to each wave W transducer 13 extends away from the perforated surface 30 and / or in the direction of the lateral edge of the optical surface 10.

[0092] Each wave W transducer 13 is firmly fastened to the optical surface 10 by any means, in particular by adhesive bonding.

[0093] Each wire 14 can be firmly fastened to the optical surface 10 by any means, in particular by adhesive bonding.

[0094] In Figure 1 and Figure 2 the exemplary embodiments shown, the wave W transducer 13 is located on the second face 11B of the optical surface 10, which is opposite the first face 11A of the optical surface 10, and the device 21 is located near this first face. Thus, this configuration enables the second face 11B facing the perforated surface 30 to be cleaned more efficiently.

[0095] In summary, the present invention relates to a unit 1 for protecting a device 21 and a detection component 2 associated with the device 21 that emits or senses radiation 23 in a region of interest that passes through an optical surface 10 of the protection unit 1. The protection unit 1 further includes at least one wave W transducer 13 configured to generate an acoustic wave W on or in the optical surface 10 in order to clean the optical region of interest 12. According to the present invention, the protection unit 1 further includes a perforated surface 30 positioned facing the optical surface 10, the perforated surface 30 including a solid portion 31 and at least one hole 32 through which the radiation 23 emitted and / or sensed by the device 21 can pass.

[0096] Of course, the present invention is not limited to the examples just described, and many modifications can be made to these examples without departing from the scope of the present invention. In particular, the various features, forms, variations, and embodiments of the present invention can be combined with each other in various combinations as long as they are compatible with each other or not mutually exclusive. In particular, all of the above variations and embodiments can be combined with each other.

Claims

1. A unit (1) for protecting an optical surface (10), the protection unit being intended to be associated with a device (21) configured to sense and / or emit radiation (23) passing through a region of interest (12) of the optical surface (10), the protection unit (1) comprising: - the optical surface (10); - a perforated surface (30), the perforated surface being fixed to the optical surface (10) and placed facing the optical surface (10), the perforated surface (30) comprising a solid part (31) and at least one hole (32) formed in the solid part (31); - at least one wave (W) transducer (13), the at least one wave transducer being mechanically coupled to the optical surface (10) and configured to generate a wave (W) that propagates through the optical surface (10) and propagates in the direction of and / or into the region of interest (12) of the optical surface (10), the wave (W) generated by the at least one wave (W) transducer (13) being an ultrasonic wave.

2. The protection unit (1) according to the previous claim, wherein, The perforated surface (30) is a grid, a radiator grille, a metal sheet having at least one hole (32), or a bumper component having at least one hole (32).

3. The protection unit (1) according to claim 1 or 2 as described above, wherein, The at least one wave (W) transducer (13) is positioned facing the solid part (31) of the perforated surface (30).

4. The protection unit (1) according to any one of claims 1 to 3, wherein, The at least one wave (W) transducer (13) is located on the side of a first face (11A) of the optical surface (10) called the inner face, the first face being intended to be on the side of the device (21) with which the protection unit (1) is intended to cooperate and opposite a second face (11B) of the optical surface (10) called the outer face and positioned facing the perforated surface (30), the wave (W) generated by the at least one wave (W) transducer (13) being a bulk wave (W).

5. The protection unit (1) according to the preceding claim, wherein, The wavelength of the wave (W) generated by the at least one wave (W) transducer (13) is greater than or equal to twice the thickness of the optical surface (10) measured in the region of interest (12).

6. The protection unit (1) according to any one of claims 1 to 3, wherein, The at least one wave (W) transducer (13) is located on the side of the outer face of the optical surface (10) positioned facing the perforated surface (30), the wave (W) generated by the at least one wave (W) transducer (13) being a Rayleigh wave (W).

7. The protection unit (1) according to the previous claim, wherein, The wavelength of the wave (W) generated by the at least one wave (W) transducer (13) is less than or equal to one fifth of the thickness of the optical surface (10) measured in the region of interest (12).

8. The protection unit (1) according to any one of claims 1 to 7, wherein, The perforated surface (30) is firmly fastened to a holder (17) by fastening tabs (16) extending through a window formed in the optical surface (10).

9. The protection unit (1) according to any one of claims 1 to 7, wherein, The perforated surface (30) is firmly fastened to the optical surface (10) by fastening tabs (16) fixed to the optical surface (10).

10. The protection unit (1) according to any one of claims 8 or 9, wherein, The at least one wave (W) transducer (13) is placed at an intermediate position between the fastening tab (16) and the region of interest (12).

11. A detection assembly (2), comprising: - The protection unit (1) according to any one of the preceding claims; - At least one device (21), the at least one device being configured to sense and / or emit radiation (23) that passes through the optical region of interest (12) of the optical surface (10) and through at least one aperture (32) of the perforated surface (30).

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