System for cleaning an optical surface

Abstract

The invention relates to a system (1) for cleaning an optical surface (3) of an optical device (2), this cleaning system comprising: - a wiper blade (10) for wiping the window, this wiper being arranged to wipe a wiping area (6) of the window other than the optical surface, the wiper being provided with a nozzle (11) for spraying fluid, in particular air, towards the optical surface (3); and - in particular an apparatus for moving the fluid, in particular a compressor or a fan, intended to supply the spraying nozzle (11).

Description

Optical surface cleaning system

[0001] The present invention relates to a system for cleaning an optical surface of an optical device, which optical device is assembled with a vehicle window, in particular a windshield.

[0002] The vehicle can be land, sea or air.

[0003] In some vehicles, a camera, for example an infrared camera, is mounted in a hole in the windshield and is located outside the sweeping path of the wiper blade(s). In this case, it is recommended to have specific camera washing systems because, after cleaning, drops often remain on the camera. Drops are also present when it rains.

[0004] The invention aims in particular to remove possible drops on the camera or pollution such as for example dust, snow, leaf debris, organic waste deposited on the optical surface of the camera, which is outside the scanning plane.

[0005] The invention thus relates to a system for cleaning an optical surface of an optical device, this cleaning system comprising: a wiper blade for wiping a window, this blade being arranged to wipe a wiping zone of the window separate from the optical surface, this blade carrying a nozzle for projecting fluid, in particular air, towards the optical surface, in particular a device for setting fluid in motion, in particular a compressor or a fan, intended to supply the projection nozzle.

[0006] The invention makes it possible to clean, using a jet of fluid, in particular an air jet, the optical surface of the optical device so as to ensure that this optical surface is sufficiently clean to allow it to function properly. For example, the air projected by the nozzle according to the invention makes it possible to expel any drops of water present on this optical surface. These drops could disrupt the detection of electromagnetic waves such as infrared or visible waves, by the optical device. The optical surface is in particular the surface through which the waves penetrate the optical device, this surface being for example opposite a lens of the optical device.

[0007] This optical device forms an infrared sensor, for example. This optical device could also be arranged as an electromagnetic wave transmitter, for example an infrared transmitter.

[0008] The invention also makes it possible to take advantage of the wiper blade to add this additional function of cleaning the optical surface of the optical device. The presence of the projection nozzle on the blade thus makes it possible to bring the fluid, in particular air, as close as possible to the optical surface to be cleaned.

[0009] The cleaning permitted by the invention is of the contactless type between the wiper and the optical surface to be cleaned. This is particularly advantageous when the optical device is assembled with the glass, protruding from this glass. The invention makes it possible to clean without having to pass the wiper in contact with the optical surface protruding from the glass, which avoids the risk of damaging the optical device, for example by rubbing the wiper too hard on the optical surface. Thus, cleaning is done using the jet of fluid and not by contact of the wiper on the optical surface.

[0010] According to one aspect of the invention, the optical device is assembled with a vehicle window, in particular a windshield. In particular, the optical device projects from the windshield.

[0011] According to one aspect of the invention, the fluid is air alone, or a liquid alone, or a mixture of liquid and air. This mixture of liquid and air can form a foam projected onto the optical surface to be cleaned.

[0012] According to one aspect of the invention, the projection nozzle is arranged at one end of the wiper blade, in particular one end of the blade, among its two opposite ends, which passes closest to the optical surface during scanning.

[0013] According to one aspect of the invention, the projection nozzle comprises a fluid outlet orifice, in particular in the form of a convergent to accelerate the fluid.

[0014] According to one aspect of the invention, the fluid outlet orifice is configured to direct the projected fluid away from the wiping zone.

[0015] In other words, the fluid that is projected by this projection nozzle is not used for cleaning the wiping area.

[0016] According to one aspect of the invention, the nozzle outlet has a fluid outlet axis which is tangent to the axis of the wiper blade.

[0017] Alternatively, the nozzle outlet has a fluid outlet axis which forms a non-zero angle with the longitudinal axis of the wiper blade, for example an angle of less than 20°, or even less than 5°.

[0018] According to one aspect of the invention, the projection nozzle comprises an internal fluid channel opening onto the fluid outlet.

[0019] According to one aspect of the invention, this internal fluid channel has a fluid inlet configured to allow the connection of a fluid supply pipe to the nozzle.

[0020] According to one aspect of the invention, the projection nozzle is formed by a part separate from the wiper and which is assembled with the wiper, in particular by snap-fastening, screwing or welding.

[0021] According to one aspect of the invention, the projection nozzle can be removably attached to the wiper.

[0022] Alternatively, the nozzle is part of the wiper, being formed on an end cap of the wiper. This end cap is usually called an "Endclip" in English. This end cap may have an aerodynamic profile, and is fixed on a mount which carries the wiper blade of the wiper.

[0023] According to one aspect of the invention, the projection nozzle can be permanently fixed, i.e. in a non-removable manner, to the broom.

[0024] According to one aspect of the invention, the spray nozzle is arranged in the longitudinal extension of the wiper blade.

[0025] According to one aspect of the invention, the cleaning system comprises at least one pipe connecting a compressor to the projection nozzle.

[0026] According to one aspect of the invention, the wiper blade is arranged to be attached to a wiper arm, and at least one pipe which connects the compressor to the spray nozzle runs along, at least over a certain length, the wiper arm.

[0027] According to one aspect of the invention, the wiper arm is connected to an electric motor arranged to set it in wiping motion.

[0028] According to one aspect of the invention, the electric motor is coupled to an angular position sensor arranged to determine the angle that the sweeper arm makes relative to a reference position.

[0029] According to one aspect of the invention, the compressor, in particular of the electric type, is arranged to compress fluid, for example air, which is then brought to the projection nozzle.

[0030] According to one aspect of the invention, the compressor is placed on a fixed support separate from the wiper blade.

[0031] According to one aspect of the invention, the cleaning system comprises a compressed air tank supplied with compressed air from the compressor, and the spray nozzle is supplied with compressed air from this compressed air tank.

[0032] Thanks to this tank which serves as a buffer tank, the invention makes it possible to have immediately available compressed air which can be brought very quickly to the projection nozzle.

[0033] According to one aspect of the invention, the cleaning system comprises a valve, in particular a solenoid valve, arranged to, in the open position, allow compressed air to flow from the tank to the projection nozzle, and in the closed position, stop the flow of compressed air from the tank to the projection nozzle.

[0034] According to one aspect of the invention, this valve can be controlled with a very rapid reaction time, making it possible to deliver compressed air to the spray nozzle in a very short time.

[0035] According to one aspect of the invention, the projection nozzle is connected to a reservoir of additional liquid, in particular a windshield washer fluid, so as to be able to be supplied, selectively, by this liquid alone, or by a mixture of this liquid and air, or by air alone.

[0036] According to one aspect of the invention, the cleaning system comprises a pump arranged to deliver liquid from the liquid reservoir to the spray nozzle.

[0037] According to one aspect of the invention, a liquid path from the liquid reservoir and an air path from the air reservoir join within a common pipe, upstream of the projection nozzle so that this projection nozzle can be selectively supplied with air and / or liquid.

[0038] According to one aspect of the invention, a check valve is placed in the air path to prevent liquid from being forced back into the air reservoir.

[0039] According to one aspect of the invention, a check valve is placed in the liquid path to prevent air from being forced back into the liquid reservoir.

[0040] According to another aspect of the invention, the projection nozzle is placed at a distance from the ends of the brush, for example at a location on the brush which is distant from its ends by more than 5% or more than 10% of the total length of the brush.

[0041] According to one aspect of the invention, the nozzle is made of plastic.

[0042] According to one aspect of the invention, the optical device is a camera, in particular an infrared camera, arranged to detect the presence of drops of water on the window, so as to trigger the operation of the wiper blade in the event of detection of drops of water.

[0043] According to one aspect of the invention, the air movement device may be a fan, instead of the compressor. This fan is in particular with radial blades.

[0044] According to one aspect of the invention, the optical device protrudes from the glass so that the optical surface to be cleaned extends beyond the glass.

[0045] Thus, cleaning this optical surface with an air jet does not damage the optical device, unlike, for example, the passage of a brush over the optical device, which passage is likely to damage the optical device by abrasion because it protrudes beyond the glass. The generation of unwanted noise by the passage of the brush over the optical device protruding from the glass, or premature wear and the deposition of rubber material from the blade on the optical device, is also avoided.

[0046] The invention also relates to an air projection nozzle arranged to be fixed to a wiper blade in order to form a cleaning system as described above.

[0047] The invention also relates to a method for cleaning an optical surface (3) of an optical device, this cleaning method comprising the following step: projecting a jet of fluid towards the optical surface using a fluid projection nozzle carried by a window wiping blade, this blade being arranged to wipe a wiping zone of the window separate from the optical surface.

[0048] According to one aspect of the invention, the method comprises the following step: controlling the projection of the fluid jet between a projection start angular position and a projection end angular position.

[0049] In other words, the jet of fluid, particularly air, is not ensured during the entire operating phase of the wiper blade, but only during a limited period of time during which the projection nozzle is as close as possible to the optical surface to be cleaned.

[0050] For example, the optical surface to be cleaned is located closest to the nozzle when the wiper is in an angular position of A degrees relative to a reference position, and the air jet is triggered between a projection start angular position of (A- d) degrees and a projection end angular position of (A+d) degrees, the angle A being for example 75° or 80° and the angle d being for example of the order of 10° or 5°.

[0051] Thus the air jet is triggered intermittently.

[0052] According to one aspect of the invention, the detection of the angular position of the brush is ensured by an angular position detector arranged at the level of the electric motor of the brush. This detector is for example of the Hall effect type.

[0053] According to another aspect of the invention, the fluid is delivered to the nozzle continuously over the entire upward and downward stroke of the wiper.

[0054] Other characteristics and advantages of the invention will appear more clearly on reading the following description, given as illustrative and non-limiting examples, and the appended drawings among which:

[0055] - illustrates, schematically and partially, a cleaning system according to an exemplary implementation of the invention;

[0056] - illustrates, schematically and partially, the cleaning system in operation;

[0057] - illustrates, schematically and partially, in section, the optical device of the system of the, projecting from the window;

[0058] - illustrates, schematically and partially, a cleaning system according to another example of implementation of the invention.

[0059] Figures 1 and 2 show a cleaning system 1 for an optical surface 3 of an optical device 2, which optical device 2 is assembled with a vehicle windshield 4.

[0060] As seen in the, the optical device 2 is assembled with the windshield 4, projecting from this windshield 4.

[0061] The optical surface 3 is the surface through which the waves enter the optical device 2, which in the example described forms an infrared sensor.

[0062] The cleaning system 1 comprises a wiping blade 10 arranged to wipe a wiping zone 6 of the windshield 4 separate from the optical surface 3.

[0063] This brush 10 carries a nozzle 11 for projecting air towards the optical surface 3.

[0064] The nozzle 11 thus delivers a jet of air 12 towards the optical surface 3.

[0065] This projection nozzle 11 is arranged at one end 14 of the wiper, among its two opposite ends, which passes closest to the optical surface 3 during scanning.

[0066] The projection nozzle 11 comprises an air outlet orifice 15, in the shape of a convergent to accelerate the fluid.

[0067] This fluid outlet orifice 15 is configured so as to direct the projected fluid outside the wiping zone 6.

[0068] In other words, the fluid which is projected by this projection nozzle 11 is not used for cleaning the wiping zone 6.

[0069] The outlet 15 of the nozzle 11 has a fluid outlet axis FS which is tangent to a longitudinal axis WL of the wiper blade 10.

[0070] The projection nozzle 11 may comprise an internal fluid channel opening onto the fluid outlet 15.

[0071] The projection nozzle 11 is formed by a part separate from the brush 10 and which is assembled with the brush 10, in particular by snap-fastening, screwing or welding.

[0072] The spray nozzle 11 can be removably attached to the wiper blade 10, and is arranged in the longitudinal extension of the wiper blade 10.

[0073] The nozzle 11 is connected to a pipe 16 for supplying fluid to the nozzle 11.

[0074] This pipe 16 connects an electric compressor 17 to the projection nozzle 11.

[0075] The wiper blade 10 is attached to a wiper arm 18, and the pipe 16 which connects the compressor 17 to the spray nozzle 11 runs along the wiper arm 18 for a certain length.

[0076] The compressor 17 is arranged to compress air which is then brought towards the projection nozzle 11. This compressor 17 is placed on a fixed support separate from the wiper blade.

[0077] The broom arm 18 is connected to an electric motor 19 arranged to put it into wiping movement.

[0078] The electric motor 19 is coupled to an angular position sensor 20 arranged to determine the angle that the sweeper arm 18 makes relative to a reference position.

[0079] In the example described, the cleaning system 1 further comprises a compressed air tank 22 supplied with compressed air from the compressor 17 which is placed upstream, and the projection nozzle 11 is supplied with compressed air from this compressed air tank 22.

[0080] Thanks to this reservoir 22 which serves as a buffer reservoir, the invention makes it possible to have immediately available compressed air which can be brought very quickly to the projection nozzle 11.

[0081] The cleaning system 1 further comprises a solenoid valve 23 arranged to, in the open position, allow compressed air to flow from the reservoir 22 to the projection nozzle 11, and in the closed position, stop the flow of compressed air from the reservoir 22 to the projection nozzle 11.

[0082] This valve 23 can be controlled with a very rapid reaction time, allowing compressed air to be delivered to the projection nozzle 11 in a very short time. This allows in particular to have a pulsed jet of air.

[0083] In the case of a pulsed air jet, it is possible to have a single opening / closing sequence of the valve 23 in the optical surface to be cleaned, or, alternatively, to have several opening / closing sequences of the valve 23 in the optical surface to be cleaned. This is made possible by the high reactivity of the solenoid valve allowing, for example, cycles whose cycle duration is less than 20 ms, and by the fact that the pulse has a very short lifetime.

[0084] If a fan or "blower" is used, it is necessary to activate the nozzle sufficiently upstream of the optical surface to be cleaned because its start-up time can take several seconds, and the fan remains on for the necessary cleaning time.

[0085] The nozzle 11 is made of plastic.

[0086] The optical device 2 is an infrared camera arranged to participate in the vehicle's autonomous driving assistance system.

[0087] The air movement device may be a fan, instead of the compressor 17. This fan has radial blades.

[0088] According to one aspect of the invention, the optical device protrudes from the glass

[0089] Cleaning using the system 1 is carried out as follows: project the air jet 12 towards the optical surface 3 using the projection nozzle 11, controlling the projection of the jet 12 between an angular position (Ad) for the start of projection and an angular position (A+d) for the end of projection.

[0090] In other words, the air jet 12 is not provided during the entire operating phase of the wiper blade, but only during a limited period of time during which the projection nozzle 11 is as close as possible to the optical surface 3 to be cleaned.

[0091] For example, the optical surface 3 to be cleaned is located closest to the nozzle when the wiper is in an angular position of A degrees relative to a reference position, and the air jet 12 is triggered between a projection start angular position of (A- d) degrees and a projection end angular position of (A+d) degrees, the angle A being for example 75° or 80° and the angle d being for example of the order of 10° or 5°.

[0092] The detection of the angular position of the brush 10 is ensured by the angular position detector 20 arranged at the level of the electric motor 19 of the brush. This detector 20 is for example of the Hall effect type.

[0093] In another example of implementation of the invention illustrated in the, the projection nozzle 11 is connected to an additional liquid reservoir 25, here a windshield washer liquid, so as to be able to be supplied, selectively, by this liquid alone, or by a mixture of this liquid and air, or by air alone.

[0094] The cleaning system comprises a pump 26 arranged to deliver liquid from the liquid reservoir 25 to the spray nozzle 11.

[0095] A liquid path 27 from the liquid reservoir 26 and an air path 28 from the air reservoir 22 join within a common pipe 29, upstream of the projection nozzle 11 so that this projection nozzle can be selectively supplied with air and / or liquid.

[0096] A check valve 30 is provided in the air path 28 to prevent liquid from being forced back into the air reservoir.

[0097] Another check valve 31 is placed on the liquid path 27 to prevent air from being forced back into the liquid reservoir 26.

[0098] In this embodiment, it is possible to distribute to the nozzle 11, depending on cleaning needs, liquid alone, or a mixture of this liquid and air, or air alone.

[0099] In an exemplary embodiment not shown, the projection nozzle is placed at a distance from the ends of the brush, for example at a location on the brush which is distant from its ends by more than 5% or more than 10% of the total length of the brush.

Claims

Cleaning system (1) for an optical surface (3) of an optical device (2), this cleaning system comprising: a wiper blade (10) for wiping a window, this blade being arranged to wipe a wiping zone (6) of the window separate from the optical surface, this blade carrying a nozzle (11) for projecting fluid, in particular air, towards the optical surface (3), in particular a device for setting the fluid in motion, in particular a compressor (17) or a fan, intended to supply the projection nozzle (11). System according to the preceding claim, in which the fluid is air alone, or a liquid alone, or a mixture of liquid and air. System according to one of the preceding claims, in which the projection nozzle (11) is arranged at one end of the wiper blade, in particular one end (14) of the blade, among its two opposite ends, which passes closest to the optical surface during scanning. System according to one of the preceding claims, in which the outlet (15) of the nozzle (11) has a fluid outlet axis (FS) which is tangent to the axis (WL) of the wiper blade. System according to one of the preceding claims, wherein the cleaning system comprises at least one pipe (16) connecting a compressor (17) to the projection nozzle (11). System according to one of the preceding claims, in which a wiper arm is connected to an electric motor (19) arranged to put it into wiping movement, and the electric motor (19) is coupled to an angular position sensor (20) arranged to determine the angle that the wiper arm makes relative to a reference position. System according to the preceding claim, in which the cleaning system comprises a compressed air tank (22) supplied with compressed air from the compressor (17), and the projection nozzle is supplied with compressed air from this compressed air tank (22). System according to claim 6 or 7, in which the cleaning system comprises a valve (23), in particular a solenoid valve, arranged to, in the open position, allow compressed air to flow from the tank to the projection nozzle (11), and in the closed position, stop the flow of compressed air from the tank to the projection nozzle (11). Air projection nozzle (11) arranged to be fixed on a wiper blade in order to form a cleaning system according to one of the preceding claims. Method for cleaning an optical surface (3) of an optical device, this cleaning method comprising the following step: projecting a jet of fluid (12) towards the optical surface (3) using a fluid projection nozzle (11) carried by a window wiper blade, this blade being arranged to wipe a wiping zone of the window separate from the optical surface.

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