Classifications

• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
  • G02B27/0006—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00 with means to keep optical surfaces clean, e.g. by preventing or removing dirt, stains, contamination, condensation
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B08—CLEANING
  • B08B—CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
  • B08B3/00—Cleaning by methods involving the use or presence of liquid or steam
  • B08B3/04—Cleaning involving contact with liquid
  • B08B3/10—Cleaning involving contact with liquid with additional treatment of the liquid or of the object being cleaned, e.g. by heat, by electricity or by vibration
  • B08B3/12—Cleaning involving contact with liquid with additional treatment of the liquid or of the object being cleaned, e.g. by heat, by electricity or by vibration by sonic or ultrasonic vibrations
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60S—SERVICING, CLEANING, REPAIRING, SUPPORTING, LIFTING, OR MANOEUVRING OF VEHICLES, NOT OTHERWISE PROVIDED FOR
  • B60S1/00—Cleaning of vehicles
  • B60S1/02—Cleaning windscreens, windows or optical devices
  • B60S1/56—Cleaning windscreens, windows or optical devices specially adapted for cleaning other parts or devices than front windows or windscreens
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
  • G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
  • G01S17/88—Lidar systems specially adapted for specific applications
  • G01S17/93—Lidar systems specially adapted for specific applications for anti-collision purposes
  • G01S17/931—Lidar systems specially adapted for specific applications for anti-collision purposes of land vehicles
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
  • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
  • G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
  • G01S7/497—Means for monitoring or calibrating
  • G01S2007/4975—Means for monitoring or calibrating of sensor obstruction by, e.g. dirt- or ice-coating, e.g. by reflection measurement on front-screen
  • G01S2007/4977—Means for monitoring or calibrating of sensor obstruction by, e.g. dirt- or ice-coating, e.g. by reflection measurement on front-screen including means to prevent or remove the obstruction
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
  • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
  • G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
  • G01S7/481—Constructional features, e.g. arrangements of optical elements
  • G01S7/4811—Constructional features, e.g. arrangements of optical elements common to transmitter and receiver
  • G01S7/4813—Housing arrangements

Definitions

• the technical context of the present invention is that of sensors and in particular devices for cleaning a surface of such sensors through which surface said sensors operate their measurements. More particularly, the invention relates to a device for cleaning an optical surface, a protection unit comprising such a cleaning device, a protection assembly comprising such a protection unit and a motor vehicle.
• the present invention relates to a cleaning device for cleaning bodies in contact with an optical surface by means of ultrasonic waves.
• cleaning it is understood here that the cleaning device is configured to remove the bodies which were present in contact with the optical surface so that, following the cleaning operation, the optical surface is free of said bodies.
• an objective sought by the present invention is to overcome the effects linked to the accumulation of bodies on an optical surface, such as in particular drops of rain, frost or snow.
• a known disadvantage of this technique is that it does not can be implemented only with particular materials and requires a particularly precise positioning of the electrodes on all the surface where one wants to control the properties of wetting, making complex even expensive its industrialization, its mass production and its integration in products for the automotive industry, for example.
• cleaning methods are known which make it possible to evacuate a liquid if accumulating on an optical surface of the sensor, the latter possibly taking the form of a support attached to the sensor or even of a windshield, via generation and propagation of ultrasonic surface waves in the optical surface.
• document WO 2012/095643 A1 describes a method for evacuating raindrops from a windshield by ultrasonic vaporization. The amplitude and frequency of vibration are chosen so that the raindrops falling on the windshield are vaporized as soon as they enter the zone of vibratory movement of the surface of the windshield.
• the techniques presented above all have drawbacks related to their integration on more compact surfaces.
• the object of the present invention is to provide a new cleaning device in order to respond at least in large part to the above problems and also to lead to other advantages.
• Another object of the invention is to allow integration of such a cleaning device in compact environments, and in particular sensors as used in the automotive field.
• Another object of the invention is to improve the cleaning efficiency of an optical surface by such a cleaning device.
• Another object of the invention is to reduce the electrical power required to drive such a cleaning device to clean the optical surface.
• At least one of the aforementioned objectives is achieved with a device for cleaning an optical surface having at least a first region of optical interest and a second region of optical interest , the cleaning device comprising at least one wave transducer intended to be acoustically coupled with the optical surface.
• the at least one wave transducer is configured to be placed in an intermediate zone located between the two regions of optical interest, such that the at least one wave transducer is configured to generate a wave propagating in a first direction in the first region of optical interest and in a second direction in the second region of optical interest.
• the wave generated by each at least one wave transducer is of the type of a surface wave. More particularly, the wave generated by each at least one wave transducer is of the type of an ultrasonic wave and/or of the type of a Lamb wave and/or of the type of a Rayleigh wave.
• each at least one wave transducer is of the type of an electronic chip configured to be able to generate the wave in question.
• each at least one wave transducer is of the type of a single electromechanical comb, an electrical polarization of which makes it possible to generate the wave, so that it propagates in the optical surface in the direction and in one and/or the other of the regions of optical interest.
• each at least one wave transducer comprises a plurality of wave generation devices, such as for example electromechanical combs.
• the cleaning device comprises several wave transducers placed side by side of each other and sharing between them one or more electromechanical combs in order to generate the wave so that it propagates in the optical surface in the direction and in one and/or the other of the regions of optical interest.
• the wave generated by each at least one 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.
• the wave generated by each at least one transducer advantageously has an amplitude of between 1 nanometer and 500 nanometers.
• the amplitude of the wave corresponds to the normal displacement of a face of the optical surface on which the wave propagates.
• the ultrasonic surface wave can be a Rayleigh wave, when the optical surface has a thickness greater than the wavelength of the ultrasonic surface wave.
• a Rayleigh wave is favored because a maximum proportion of the wave's energy is concentrated on the face of the optical surface on which it propagates, and can be transmitted to a body, for example a raindrop, resting on the optical surface.
• the device according to the invention thus makes it possible to effectively clean the optical surface by means of the propagation of the wave in said optical surface, so that a body, such as for example a drop of rain, in contact with the optical surface is set in motion by the wave generated by each at least one wave transducer.
• the optical surface can be of any type and fulfill any function vis-à-vis one or more devices intended to emit or capture radiation passing through said optical surface.
• the optical surface may be an optical lens making up the device(s) through which the radiation passes or even a surface protection positioned opposite the optical lens(es) of the device(s).
• each at least one wave transducer is located in an intermediate position between the first region of optical interest and the second region of optical interest, forming the intermediate zone.
• the intermediate zone is understood in any direction, depending on the relative arrangement of the regions of optical interest.
• each at least one wave transducer is located laterally between the first region of optical interest and the second region of optical interest, and/or each at least one wave transducer is located vertically between the first region of optical interest and the second region of optical interest, and/or each at least one wave transducer is located longitudinally between the first region of optical interest and the second region of optical interest.
• the lateral, vertical and longitudinal directions are taken respectively according to a lateral direction of the motor vehicle extending between two side fenders of said motor vehicle, in a vertical direction of the motor vehicle extending between wheels and a roof liner of said motor vehicle, and in a longitudinal direction of the motor vehicle extending between a rear bumper and a front bumper of said vehicle automobile.
• the first and the second direction are opposed to each other, so that a first guideline characteristic of the first direction extends parallel or substantially parallel to a second guideline characteristic of the second direction.
• the first guideline forms an angle of between 150° and 210° with the second guideline.
• the at least one transducer is configured to be able to generate a wave propagating both in a first half-plane comprising the first region of optical interest and in a second half-plane comprising the second region of optical interest, each half-plane is disjoint from the other half-plane.
• the half-planes are opposite each other and relative to the at least one wave transducer.
• the cleaning device according to the first aspect of the invention advantageously comprises at least one of the improvements below, the technical characteristics forming these improvements being able to be taken alone or in combination:
• the at least one wave transducer comprises exactly one wave transducer, the wave transducer being configured to generate a first wave propagating in the direction of the first region of optical interest and a second wave propagating towards the second region of optical interest.
• the at least one wave transducer comprises (i) a first wave transducer configured to generate a first wave so that it propagates through the first region of optical interest, and (ii) a second wave transducer configured to generate a second wave such that it propagates through the second region of optical interest.
• each at least one wave transducer comprises a reflector member configured to reflect the wave generated by one of the wave transducers and extending in the direction of the other of the wave transducers, so that the waves generated by the wave transducers do not propagate in the intermediate zone of the optical surface.
• the first wave generated by the first wave transducer is of the type of a unidirectional wave propagating towards and through the first region of optical interest
• the second wave generated by the second transducer wave is of the type of a unidirectional wave propagating in the direction and through the second region of optical interest
• the first wave transducer extends parallel to the second wave transducer.
• a distance separating the first wave transducer from the second wave transducer is between 5% and 10% of a dimension of a longest edge of the optical surface.
• a distance separating the first wave transducer from the second wave transducer is less than 30 mm, preferably less than 20 mm, preferably less than 10 mm.
• each at least one wave transducer extends along an edge of the corresponding optical region of interest, and along a length between 80 % and 120% of a length of the edge of said optical region of interest.
• each at least one wave transducer extends over a length at least equal to the length of the edge of the optical region of interest against or facing which it is installed.
• the piezoelectric layer of each at least one wave transducer forms at least one strip extending over one face of the optical surface.
• each wave transducer preferably comprises several wave transducers which share the same piezoelectric layer.
• the wave transducers are arranged electrically in series with respect to each other or in parallel with respect to each other, or driven independently of each other;
• the piezoelectric layer has a thickness between 1 ⁇ m and 500 ⁇ m.
• the piezoelectric layer has a thickness of less than 250 ⁇ m, or even less than 10 ⁇ m.
• the thickness of the piezoelectric layer is defined according to the thickness of the optical surface with which the cleaning device according to the first aspect of the invention is intended to collaborate.
• a ratio between the thickness of the optical surface and that of the piezoelectric layer is preferably greater than 2, preferably greater than 10, or even greater than 50.
• the thickness of the piezoelectric layer is taken in a direction perpendicular to the face of said piezoelectric layer intended to be in contact with the optical surface, and the thickness of the optical surface is taken in a direction perpendicular to said optical surface;
• the piezoelectric layer is optionally deposited on the optical surface by a process chosen from physical vapor deposition, chemical vapor deposition, magnetron sputtering and electron cyclotron resonance.
• the piezoelectric layer is firmly attached to the optical surface by bonding. This configuration is particularly preferred in the case of a piezoelectric layer of greater thickness;
• the piezoelectric layer is formed of a material chosen from the group formed by lithium niobate, aluminum nitride, zinc oxide, lead titano-zircanate, and mixtures thereof ;
• the piezoelectric layer is alternatively opaque to visible light or transparent.
• transparent or “opaque” is meant respectively a transparency or an opacity to electromagnetic radiation whose emission spectrum is included in the visible to the human eye and / or in the infrared and / or in the 'ultraviolet.
• the piezoelectric layer or layers of each at least one wave transducer comprise polarity electrodes configured to allow electrical polarization of the piezoelectric layer necessary for its operation.
• the electrodes of polarity are at an opposite electrical potential, that is to say they are intended to be electrically supplied by electrical voltages of opposite signs.
• the polarity electrodes each comprise a comb comprising a branch from which fingers extend, the branch and the fingers together forming said comb.
• the combs of each polarity electrode are interdigitated, that is to say that the fingers of each comb are placed facing each other in an alternating manner.
• each of the fingers of a comb has a width equal to a quarter of the fundamental wavelength of the wave generated by the at least one corresponding wave transducer.
• an interval between two consecutive fingers of the same comb is equal to a quarter of the fundamental wavelength of the wave generated by the at least one corresponding wave transducer.
• the interval between the fingers of a comb forming one of the polarity electrodes determines the resonant frequency of the corresponding wave transducer.
• the alternating electrical polarization of the electrodes of opposite polarity induces a mechanical response of the piezoelectric material, the latter expanding and contracting under the effect of the electrical polarization. This results in the generation of the surface wave which then propagates in the optical surface in the direction of the regions of optical interest;
• the polarity electrodes are metallic. They can be in chrome, or aluminum or in the combination of a grip layer such as titanium and a conductive layer such as gold.
• the polarity electrodes can be made of a conductive transparent oxide, for example chosen from indium tin oxide, zinc oxide doped with aluminum and mixtures thereof.
• each at least one wave transducer can be transparent and be formed from such electrodes and from a transparent piezoelectric layer of lithium niobate or zinc oxide.
• the polarity electrodes are for example deposited on the piezoelectric layer by an evaporation or sputtering process and shaped by photolithography.
• the polarity electrodes can also be printed, for example by inkjet printing.
• they can be printed on a flexible thermoplastic material, and be applied by transfer to the piezoelectric layer;
• each at least one wave transducer is electrically connected to a source of bias via electrical connectors which extend between said at least one wave transducer and through the intermediate zone of the surface optical.
• the electrical connectors are electrically connected to the polarity electrodes in order to supply electrical energy necessary for the operation of the at least one wave transducer.
• a protection unit comprising (i) an optical surface having at least a first region of optical interest and a second region of optical interest, and (ii) a cleaning device according to the first aspect of the invention or according to any one of its improvements, the cleaning device being acoustically coupled with the optical surface.
• the protection unit in accordance with the second aspect of the invention advantageously comprises at least one of the improvements below, the technical characteristics forming these improvements being able to be taken alone or in combination:
• the regions of optical interest of the optical surface are not superimposed with the at least one wave transducer of the cleaning device according to the first aspect of the invention.
• the at least one transducer is located at a distance from each region of optical interest of the optical surface.
• the at least one transducer is located on a region of the optical surface, called transduction region, different and separate from the regions of optical interest of said optical surface.
• This advantageous configuration makes it possible not to obscure each region of optical interest and to allow the proper functioning of a device.
• the optical surface is a protective surface for a device, this advantageous configuration makes it possible not to obscure each region of optical interest and to allow the correct operation of the device located opposite and capturing and /or emitting radiation through said optical region of interest;
• the side of the optical surface on which the wave generated by the at least one wave transducer propagates is flat or curved. If the optical surface is curved, then a radius of curvature of the face in question is greater than the wavelength of the wave generated by the at least one wave transducer.
• the face of the optical surface is possibly rough. In this case, roughnesses forming the face of the optical surface are preferably less than the length fundamental wave of the wave generated by the at least one wave transducer, in order to prevent them from significantly affecting their propagation;
• the optical surface is in the form of a plate, preferably flat or having at least one curvature in one direction.
• the optical surface can be a lens.
• the optical surface can take any shape
• the optical surface can be oriented and tilted in any orientation and/or along any inclination.
• the optical surface can be arranged parallel to a horizontal plane, or it can form an angle a greater than 10°, or even greater than 20°, or even greater than 45°, or even greater than 70° relative to the horizontal plane.
• the optical surface can be arranged vertically;
• the optical surface comprises an acoustically conductive portion, preferably made of glass, each at least one wave transducer being acoustically coupled to the acoustically conductive portion, so that the wave generated by the at least one transducer d
• the wave propagates in the acoustically conductive portion of the optical surface.
• the acoustically conductive portion of the optical surface extends over all or part of the optical surface.
• the acoustically conductive portion of the optical surface comprises the regions of optical interest of said optical surface.
• the optical surface comprises a monolayer or multilayer coating which covers one side of the acoustically conductive portion.
• the optical surface comprises a stack formed at least of an acoustically insulating portion and of the acoustically conducting portion stacked on top of each other.
• the acoustically conductive portion is preferably removably mounted on the acoustically insulating portion;
• the optical surface is preferably optically transparent.
• transparent is meant a transparency to electromagnetic radiation whose emission spectrum is included in the visible range for the human eye and/or in the infrared and/or in the ultraviolet.
• a detection assembly comprising (i) a protection unit according to the second aspect of the invention or according to any one of its improvements, and (ii) at least two devices, each device being configured to pick up and/or emit radiation through one of the regions of optical interest of the optical surface.
• each device is configured to capture and/or emit radiation. To this end, it comprises a sensor and/or a radiation emitter.
• each device is preferably chosen from an optical remote sensing device, such as for example a lidar, a photographic device, a camera, a radar, an infrared sensor and an ultrasonic rangefinder.
• the protection unit makes it possible to facilitate the correct operation of each device, since the optical region of interest of the optical surface through which the radiation captured or emitted by said device is cleaned by the compliant cleaning device to the first aspect of the invention and collaborating with the optical surface.
• This advantageous configuration thus makes it possible to reduce the interference between bodies which would have been present on the optical surface, at the level of the optical regions of interest, and the radiation passing through said optical regions of interest.
• the protective assembly in accordance with the third aspect of the invention advantageously comprises at least one of the improvements below, the technical characteristics forming these improvements being able to be taken alone or in combination: [55] - the optical surface is located opposite the devices of the protection unit in order to protect said devices. Preferably, the optical surface is located at a distance from the devices, so that it is not in contact with them, in a direction substantially parallel to the radiation emitted or picked up by said devices. Alternatively, the optical surface is directly in contact with the devices, and is for example in contact with the sensor and/or the transmitter of said devices;
• the optical surface is of the type of a lens intended to transform and/or deflect the radiation generated or captured by the devices located opposite.
• the optical surface is an optical protection member which does not transform and/or deflect the radiation passing through the optical surface, for example to protect the sensor and/or the transmitter.
• one and/or the other of the devices comprises the optical surface which is then a lens, or the optical surface is a member for protecting one and/or the other of the devices;
• the detection assembly includes a processing unit configured to analyze, preferably only, the radiation captured by the devices through the corresponding optical regions of interest.
• a processing unit configured to analyze, preferably only, the radiation captured by the devices through the corresponding optical regions of interest.
• an analysis unit is adapted in a variant according to which all or part of the transducer is contained in an optical field of the device.
• the at least one wave transducer of the cleaning device is arranged outside an optical field of each device.
• This advantageous configuration thus makes it possible to limit any shading effects on said devices, thus optimizing the capture and/or the emission of radiation through the optical surface.
• the “optical field” is the portion of space towards which one of the devices is capable of emitting radiation and/or from which it is capable of capturing radiation;
• the radiation emitted or captured by the devices has an electromagnetic spectrum that extends into the visible to the human eye and/or into the infrared and/or into the ultraviolet;
• each at least one wave transducer is acoustically coupled to the optical surface in order to be able to generate the wave through the corresponding optical region of interest; [61] - according to a first variant embodiment, each at least one wave transducer is firmly fixed in contact with the optical surface.
• each wave transducer is firmly attached to the optical surface by any means, such as for example by bonding using a polymeric adhesive which acoustically couples each wave transducer to the optical surface, or by molecular adhesion, or by means of a thin metallic layer providing adhesion between the optical surface and the piezoelectric layer of each wave transducer, or by means of a method comprising a step of melting a portion of the piezoelectric layer and/or of a portion of the optical surface followed by a step consisting in compressing together the piezoelectric layer and the optical surface, the respective molten portions of the optical surface and of the piezoelectric layer being in contact with one another.
• each at least one wave transducer is arranged in an intermediate position between the optical surface and the device, relative to the radiation captured and/or emitted by the devices.
• each at least one transducer is protected by the optical surface from bad weather and/or projections, the optical surface acting as a protective surface for the at least one wave transducer.
• each at least one wave transducer is then configured to generate the wave - preferably of the type of a Lamb wave - so that it reaches the face of the optical surface opposite to to the devices and in contact with which a body, for example a drop of rain, is possibly present;
• the optical surface is arranged in an intermediate position between the at least one wave transducer and the devices, relative to the radiation captured and/or emitted by the devices.
• the optical surface is no longer a protective surface for the at least one wave transducer, but it can remain one for the devices.
• the at least one transducer is in contact with the face of the optical surface opposite the devices.
• the at least one wave transducer is configured to emit a wave—preferably of the type of an ultrasonic surface wave—which propagates on this face.
• the protective assembly advantageously comprises a cover superimposed on each at least one wave transducer and configured to define a protective housing of said at least one wave transducer;
• a motor vehicle comprising a detection assembly in accordance with the third aspect of the invention or according to any of its improvements.
• FIG.1 illustrates a side view of a first embodiment of a cleaning device according to the first aspect of the invention
• FIGURE 1 illustrates a top view of the cleaning device shown in FIGURE 1;
• FIG.3 illustrates a side view of a second embodiment of a cleaning device according to the first aspect of the invention
• FIG.4 shows a top view of the cleaning device shown in FIGURE 3.
• variants and different embodiments of the invention may be associated with each other, in various combinations, insofar as they are not incompatible or exclusive of each other.
• variants of the invention may be imagined comprising only a selection of characteristics described below in isolation from the other characteristics described, if this selection of characteristics is sufficient to confer a technical advantage or to differentiate the invention from to the state of the prior art.
• all the variants and all the embodiments described can be combined with one another if nothing prevents this combination from a technical point of view.
• the invention relates to a cleaning device 5, a protection unit 50 and a detection assembly 500.
• the cleaning device 5 comprises at least one transducer 70, 70A, 70B intended to be able to be coupled acoustically to an optical surface 10 which comprises at least a first region of optical interest 100A and a second region of optical interest 100B.
• the optical surface is not part of the cleaning device 5 according to the first aspect of the invention.
• the protection unit 50 comprises the cleaning device 5 acoustically coupled to the optical surface 10.
• the optical surface 10 is indeed part of the protection unit, associated with the cleaning device 5.
• the transducers 70, 70A, 70B are acoustically coupled to the optical surface 10 in order to generate a wave in or on said optical surface 10 in order to be able to remove bodies 40 therefrom present on its surface, such as for example drops of water;
• the detection assembly 500 includes both the optical surface 10 with which the cleaning device 5 is associated, as well as at least two devices 20A, 20B configured to capture and/or emit radiation R through of one of the regions of optical interest 100A, 100B of the optical surface 10.
• the detection assembly 500 advantageously comprises a housing 52 which defines a chamber 55 housing the at least two devices 20A, 20B.
• the chamber 55 is delimited laterally by a solid wall 60 of the box 52 and, longitudinally by the optical surface 10.
• the surface optic 10 closes the chamber 55 in an airtight and watertight manner.
• the devices 20A, 20B housed in the chamber 55 are protected from the weather.
• Each at least two devices 20A, 20B comprises a sensor 25 configured to pick up R radiation and/or a transmitter configured to emit R radiation.
• each at least two devices 20A, 20B further comprises a lens 30 making it possible to direct the radiation R emitted and/or captured towards the sensor 25.
• one of the at least two devices 20A, 20B is of the type of a lidar which is configured to emitting laser radiation and capturing in return the part reflected by an object of this laser radiation, or one of the at least two devices 20A, 20B is of the type of a camera configured to detect a luminous flux forming the radiation R .
• the longitudinal direction is taken in a direction substantially parallel to the radiation R, and the lateral direction is defined in a direction substantially perpendicular to said radiation R.
• each at least two devices 20A, 20B is characterized by an optical field CO which corresponds to a portion of space from which it is capable of acquiring and/or emitting radiation R. Outside this optical field CO, no R radiation can be emitted and/or picked up by the sensor 25 of one of the at least two devices 20A, 20B.
• the optical surface 10 completely covers the sensor 25 of at least two devices 20A, 20B, simultaneously. In this way, the optical surface 10 thus forms a protection member 35 for the at least two devices 20A, 20B. Consecutively, when, for example, the protection unit 50 is mounted on a motor vehicle which moves along a direction X, the optical surface 10 forms a barrier against bodies 40, such as for example dust, mud particles or raindrops, which then come into contact with an outer face 45 of the optical surface 10, opposite the devices 20A, 20B.
• bodies 40 such as for example dust, mud particles or raindrops
• the optical surface 10 is transparent to the R radiation received and/or emitted by the sensor 25 of each device 20A, 20B.
• the optical surface 10 is transparent at its regions of interest 100A, 100B.
• the optical surface 10 is in the form of a plate whose thickness e P is for example between 0.5 mm and 5 mm.
• the optical surface 10 can be curved, and for example have the shape of a lens.
• the cleaning device 5 comprises at least one wave transducer 70, 70A, 70B intended to be acoustically coupled with the optical surface 10, the at least one transducer 70, 70A, 70B d the wave being configured to be placed in an intermediate zone 200 of the optical surface 10 located between the two regions of optical interest 100A, 100B.
• the at least one wave transducer 70, 70A, 70B is configured to generate a wave WL, WL1, WL2 which propagates:
• the first direction and the second direction are different.
• they are advantageously located, relative to the at least one wave transducer 70, 70A, 70B in different half-planes.
• the first and second directions are advantageously located opposite one another with respect to the at least one wave transducer 70, 70A, 70B.
• this advantageous configuration results directly from the location of the at least one wave transducer 70, 70A, 70B with respect to the regions of optical interest 100A, 100B of the optical surface 10: the at least one transducer 70 , 70A, 70B wave is located in the spacer zone 200.
• each at least one wave transducer 70, 70A, 70B is arranged between the two regions of optical interest 100A, 100B of the optical surface 10.
• each at least one wave transducer 70, 70A, 70B is configured to generate at least one WL wave in the direction and in at least one, if not both, regions of optical interest 100A, 100B of the surface lens 10:
• the cleaning device 5 comprises a single wave transducer 70 located in the intermediate zone 200 of the optical surface 10, so that the transducer 70 d the wave simultaneously generates (i) a first wave WL1 which propagates in the direction and in the first region of optical interest 100A and (ii) a second wave WL2 which propagates in the direction and in the second region of optical interest 100B;
• the cleaning device 5 comprises two wave transducers 70A, 70B which are all located in the intermediate zone 200 of the optical surface 10.
• the first wave transducer 70A generates a wave WL1 which propagates exclusively in the direction and in the first region of optical interest 100A and (ii) the second wave transducer 70A generates a wave WL2 which propagates exclusively in direction and in the second region of optical interest 100B.
• each wave transducer 70, 70A, 70B comprises a reflector member configured to reflect the WL wave generated by said wave transducer 70, 70A, 70B and extending in the direction of the other transducer 70, 70A, 70B wave.
• the WL wave generated by the wave transducers 70, 70A, 70B does not propagate towards and in the intermediate zone 200 of the optical surface 10.
• the WL wave generated by each transducer 70, 70A, wave 70B propagates only in the direction and in the region of optical interest 100A, 100B located opposite said wave transducer 70, 70A, 70B and opposite the intermediate zone 200 relative to said transducer 70, 70A, 70B wave considered.
• the cleaning device 5 can comprise more than two wave transducers 70, 70A, 70B to generate a WL wave in the direction of one and/or the other of the regions of optical interest 100A, 100B of the optical surface 10.
• the present invention notably addresses all the combinations resulting from the two embodiments mentioned above.
• each at least one wave transducer 70, 70A, 70B extends along an edge of the optical region of interest 100A, 100B, preferably along a length of between 80% and 120 % of a length of the edge of said optical region of interest 100A, 100B.
• the wave transducers 70, 70A, 70B extend parallel to each other, so that a distance between each transducer 70, 70A, 70B of wave is constant between two terminal ends of said transducers 70, 70A, 70B of wave.
• each at least one wave transducer 70, 70A, 70B borders one and/or the other region of optical interest 100A, 100B of the optical surface , so that said regions of optical interest 100A, 100B are finally not superimposed with each at least one wave transducer 70, 70A, 70B.
• At least part of - and preferably entirely - each region of optical interest 100A, 100B is contained in the optical field CO of one of the devices 20A, 20B located opposite.
• the at least one wave transducer 70, 70A, 70B is systematically placed outside the optical field CO of all the devices 20A, 20B, such that said at least one wave transducer 70, 70A, 70B d wave does not interfere or substantially does not interfere with the R radiation passing through the regions of optical interest 100A, 100B.
• the at least one wave transducer 70, 70A, 70B can be located on one side and/or the other of the optical surface 10:
• the at least one wave transducer 70, 70A, 70B is located on a face to be cleaned 45 of the optical surface 10.
• the clean face 45 is the face of the optical surface 10 on which the bodies 40 to be evacuated by the cleaning device 5 - or the protection unit 50 - are located.
• the face to be cleaned 45 is the face of the optical surface 10 which is located opposite the devices 20A, 20B;
• the at least one wave transducer 70, 70A, 70B is located on an internal face 90 of the optical surface 10.
• the internal face 90 is formed by the face opposite the face to be cleaned 45 of the optical surface 10.
• the internal face 90 is the face of the surface optical 10 which is located directly opposite the devices 20A, 20B.
• Each at least one wave transducer 70, 70A, 70B comprises a piezoelectric layer 80 and polarity electrodes 85 of polarity configured to allow electrical polarization of the piezoelectric layer necessary for the operation of each at least one transducer 70, 70A, 70B wave.
• each at least one wave transducer 70, 70A, 70B makes it possible to generate a wave WL of the type of a surface ultrasonic wave or of a Lamb wave or of the Rayleigh type, said wave propagating in the optical surface 10, at least at the level of the regions of optical interest 100A, 100B:
• each at least one wave transducer 70, 70A, 70B it is necessary to supply electrical energy which will make it possible to generate, for example, the mechanical oscillation of the piezoelectric layer at the origin of the wave produced by said at least one wave transducer 70, 70A, 70B.
• the electrical energy is conveyed by electrical connectors 86 intended to be electrically connected to a bias source.
• the electrical connectors 86 extend between each at least one wave transducer 70, 70A, 70B and through the intermediate zone 200 of the optical surface 10.
• the electrical connectors 86 are electrically connected to the polarity electrodes 85.
• the electrical connectors 86 can be electrically connected to the polarity electrodes 85 according to any form of electrical architecture, and in particular according to one or more serial and/or parallel links connecting one or more wave transducers 70, 70A, 70B to each other .
• the invention relates to a device 5 for cleaning an optical surface 10 having at least a first region of optical interest 100A and a second region of optical interest 100B separated by an intermediate region 200.
• at least one wave transducer 70, 70A, 70B is acoustically coupled with the optical surface 10 in order to generate a wave propagating (i) towards and in the first region of optical interest 100A and (ii) towards and in the second region of optical interest 100B.
• the cleaning device 5 comprises a single wave transducer 70, 70A, 70B generating the wave simultaneously towards and in the two regions of optical interest 100A, 100B or the cleaning device 5 comprises at least two wave transducers 70, 70A, 70B each generating a wave which propagates towards and in a single region of optical interest 100A, 100B.

Landscapes

• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Investigating Or Analysing Materials By Optical Means (AREA)
• Cleaning In General (AREA)
• Cleaning By Liquid Or Steam (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=80999756

Family Applications (1)

Country Status (4)

Family Cites Families (6)

• 2021
  • 2021-12-23 FR FR2114462A patent/FR3131234A1/fr active Pending
• 2022
  • 2022-12-15 EP EP22836169.7A patent/EP4453633A1/de active Pending
  • 2022-12-15 CN CN202280084958.6A patent/CN118435100A/zh active Pending
  • 2022-12-15 WO PCT/EP2022/086116 patent/WO2023117676A1/fr not_active Ceased

Also Published As

Similar Documents

Legal Events