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), comprising:-a wiper blade (10) for a window, arranged to wipe a wiping area (6) of the window separate from the optical surface, the blade bearing a nozzle (11) for spraying a fluid, in particular air, in the direction of the optical surface (3),-in particular a nozzle (12) for spraying a fluid, in particular air, in the direction of the optical surface (3), device for moving a fluid, in particular a compressor or blower, intended to supply a spray nozzle (11).

Description

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

[0002] The vehicle may be a land vehicle, a sea vehicle or an air vehicle.

[0003] In some vehicles, a camera, for example of the infrared type, is provided, which is mounted in an aperture in the windshield and outside the sweeping area of ​​one or more wiper blades. In this case, it is advisable to equip the camera with a specific washing system, since droplets often remain on the camera after cleaning. Droplets are also present when it rains.

[0004] The invention aims in particular at removing any drops of liquid on the camera, or contaminants such as dust, snow, leaf fragments, organic waste deposited on the optical surfaces of the camera located outside the cleaning area.

[0005] One subject of the invention is therefore a system for cleaning an optical surface of an optical device, the cleaning system comprising:

[0006] a wiper blade for the window, the blade being arranged to wipe a wiping area of ​​the window separate from the optical surface, the blade carrying a nozzle for ejecting a fluid, in particular air, in the direction of the optical surface,

[0007] In particular, a device for setting a fluid in motion, in particular a compressor or a blower, which device is intended to supply a spray nozzle.

[0008] The invention makes it possible to clean an optical surface of an optical device by means of a fluid jet, in particular an air jet, in order to ensure that the optical surface is sufficiently clean to allow its correct operation. For example, the air ejected by the nozzle according to the invention makes it possible to drive off any water drops present on the optical surface. These droplets may disrupt the detection of electromagnetic waves, such as infrared or visible waves, by the optical device. The optical surface is in particular a surface through which the waves enter the optical device, for example a surface facing a lens of the optical device.

[0009] For example, the optical device forms an infrared sensor.The optical device can also be arranged as a transmitter of electromagnetic waves, for example an infrared transmitter.

[0010] Furthermore, the invention makes it possible to benefit from the wiper blade in order to add the additional function of cleaning the optical surfaces of the optical device.The presence of a spray nozzle on the blade makes it possible to bring a fluid, in particular air, as close as possible to the optical surface to be cleaned.

[0011] The cleaning allowed by the invention is of the type without contact between the blade and the optical surface to be cleaned. This is particularly advantageous when the optical device is attached to a window and thus protrudes from this window. The invention makes it possible to clean without having to bring the blade into contact with the optical surface protruding from the window, and this avoids the risk of damaging the optical device, for example by rubbing the blade too hard on the optical surface. Thus, cleaning is performed by means of a fluid jet and not by contact of the blade on the optical surface.

[0012] According to one of the aspects of the invention, the optical device is attached to a vehicle window, in particular a windshield. In particular, the optical device protrudes from the windshield.

[0013] According to one of the aspects of the present invention, the fluid is only air, or only liquid, or a mixture of liquid and air. This mixture of liquid and air can form foam that is sprayed onto the optical surface to be cleaned.

[0014] According to one of the aspects of the invention, the spray nozzle is arranged at one end of the wiper blade, in particular at the end of the blade, which of its two opposite ends is closest to the optical surface during cleaning.

[0015] According to one of the aspects of the invention, the spray nozzle comprises a fluid outlet orifice which in particular has a converging shape in order to accelerate the fluid.

[0016] According to one of the aspects of the invention, the fluid outlet orifice is configured to direct the ejected fluid outside the wiping area.

[0017] In other words, the fluid sprayed by the spray nozzle is not used to clean the wiping area.

[0018] According to one of the aspects of the invention, the outlet of the nozzle has a fluid outlet axis which is tangential to the axis of the wiper blade.

[0019] As a variant, the outlet of the nozzle has a fluid outlet axis forming a non-zero angle (for example an angle less than 20°, or even less than 5°) with the longitudinal axis of the wiper blade.

[0020] According to one of the aspects of the present invention, the spray nozzle includes an internal fluid passage leading to a fluid outlet.

[0021] According to one of the aspects of the invention, the internal fluid passage has a fluid inlet configured to allow connection of a conduit for conveying fluid towards the nozzle.

[0022] According to one of the aspects of the invention, the spray nozzle is formed by a part which is separate from the wiper blade and which is connected to the wiper blade, in particular by snap-fastening, screwing or welding.

[0023] According to one of the aspects of the invention, the spray nozzle may be removably fastened to the scraper blade.

[0024] As a variant, the nozzle forms part of the scraper blade, in particular on the end section of the scraper blade. This end section is usually called an "end clip". This end section can have an aerodynamic profile and is fastened to a mounting of a scraper plate supporting the scraper blade.

[0025] According to one of the aspects of the invention, the spray nozzle can be permanently, ie in a non-removable manner, fastened to the wiper blade.

[0026] According to one of the aspects of the invention, the spray nozzles are arranged in the longitudinal extension of the wiper blade.

[0027] According to one of the aspects of the invention, the cleaning system comprises at least one conduit connecting the compressor to the spray nozzle.

[0028] According to one of the aspects of the invention, the wiper blade is arranged to be attached to a wiper arm, and at least one conduit connecting the compressor to the injection nozzle extends at least over a certain length along the wiper arm.

[0029] According to one of the aspects of the invention, the wiper arm is connected to a motor arranged to put the wiper arm into a wiping movement.

[0030] According to one of the aspects of the invention, the motor is coupled to an angular position sensor arranged to determine the angle of the wiper arm relative to a reference position.

[0031] According to one of the aspects of the invention, a compressor, in particular of the electric type, is arranged to compress a fluid, for example air, which is then delivered towards the injection nozzle.

[0032] According to one of the aspects of the invention, the compressor is placed on a fixed support separate from the wiper blade.

[0033] According to one of the aspects of the present invention, the cleaning system comprises a compressed air reservoir which is supplied with compressed air from a compressor, and the spray nozzle is supplied with compressed air from the compressed air reservoir.

[0034] By means of this reservoir acting as a buffer reservoir, the invention makes available immediately compressed air which can be delivered very quickly towards the injection nozzles.

[0035] According to one of the aspects of the invention, the cleaning system comprises a valve, in particular a solenoid valve, arranged to permit circulation of compressed air from the reservoir towards the spray nozzle in an open position and to stop circulation of compressed air from the reservoir towards the spray nozzle in a closed position.

[0036] According to one of the aspects of the invention, the valve can be controlled with a very fast reaction time, so that compressed air can be delivered to the spray nozzle in a very short time.

[0037] According to one of the aspects of the invention, the spray nozzle is connected to a reservoir of additional liquid, in particular windscreen washer fluid, so as to be able to be selectively supplied with only this liquid, or a mixture of this liquid and air, or only air.

[0038] According to one of the aspects of the invention, the cleaning system comprises a pump arranged to deliver liquid from a liquid reservoir towards the spray nozzle.

[0039] According to one of the aspects of the invention, the liquid path from the liquid reservoir and the air path from the air reservoir meet in a common conduit upstream of the spray nozzle, so that the spray nozzle can be selectively supplied with air and / or liquid.

[0040] According to one of the aspects of the present invention, a check valve is placed on the air path to prevent liquid from being discharged into the air reservoir.

[0041] According to one of the aspects of the present invention, a check valve is placed on the liquid path to prevent air from being discharged into the liquid reservoir.

[0042] According to another of the aspects of the invention, the spray nozzle is placed at a distance from the end of the blade, for example at a position on the blade more than 5% or 10% of the total length of the blade away from the end of the blade.

[0043] According to one of the aspects of the invention, the nozzle is made of plastic.

[0044] According to one of the aspects of the invention, the optical means is a camera, in particular an infrared camera, arranged to detect the presence of water drops on the window in order to trigger the operation of the wiper blade if water drops are detected.

[0045] According to one of the aspects of the invention, the device for setting air in motion may be a blower, rather than a compressor. The blower is in particular a blower with radial blades.

[0046] According to one of the aspects of the invention, the optical device protrudes from the window so that the optical surface to be cleaned extends beyond the window.

[0047] Thus, cleaning the optical surface by means of an air jet does not damage the optical device, for example, unlike the passage of a scraper blade over the optical device, which is susceptible to damage due to wear, since the optical device extends beyond the window. It is also avoided that the scraper blade passes over the optical device extending beyond the window, generating unwanted noise, or premature wear, and rubber material from the scraper blade is deposited on the optical device.

[0048] Another subject of the invention is a nozzle for ejecting air, which nozzle is arranged to be fastened to a wiper blade in order to form a cleaning system as described above.

[0049] Another subject of the invention is a method for cleaning an optical surface (3) of an optical device, the cleaning method comprising the following steps:

[0050] - ejecting a fluid jet in the direction of the optical surface using a nozzle for ejecting the fluid carried by a wiper blade for the window, the blade being arranged to wipe a wiping area of ​​the window separate from the optical surface.

[0051] According to one of the aspects of the present invention, the method involves the following steps:

[0052] - Controlling the ejection of the fluid jet between an ejection start angular position and an ejection end angular position.

[0053] In other words, the fluid jet, in particular air, is not ensured during the entire operating phase of the wiper blade, but only during a limited period of time when the jet nozzle is closest to the optical surface to be cleaned.

[0054] For example, when the wiper blade is at an angular position of A degrees relative to the reference position, the optical surface to be cleaned is closest to the nozzle, and the air jet is triggered between an injection start angular position of (Ad) degrees and an injection end angular position of (A+d) degrees, where angle A is, for example, 75° or 80°, and angle d is, for example, approximately 10° or 5°.

[0055] Therefore, the air jets are triggered intermittently.

[0056] According to one of the aspects of the invention, the angular position of the wiper blade is detected by an angular position detector arranged at the motor of the wiper blade. The detector is for example of the Hall effect type.

[0057] According to another of the aspects of the present invention, fluid is delivered to the nozzle in a continuous manner throughout the entire ascending and descending stroke of the wiper blade.

[0058] Other characteristics and advantages of the invention will become more clearly apparent from a reading of the following description, given by way of illustrative and non-limiting examples, and of the accompanying drawings, in which:

[0059] -[ Figure 1 ] schematically and partially illustrates a cleaning system according to an example of an embodiment of the present invention;

[0060] -[ Figure 2 ] schematically and partially illustrates during operation [ Figure 1 ] in the cleaning system;

[0061] -[ Figure 3 ] schematically and partially in cross-section [ Figure 1 ] an optical device of the system, the optical device protruding from the window;

[0062] -[ Figure 4 ] schematically and partially illustrates a cleaning system according to another embodiment example of the present invention.

[0063] Figure 1 and Figure 2 A system 1 for cleaning an optical surface 3 of an optical device 2 attached to a vehicle windshield 4 is shown.

[0064] As in [ Figure 3 ], the optical device 2 is connected to the windshield 4 so as to protrude from the windshield 4.

[0065] 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.

[0066] The cleaning system 1 comprises a wiper blade 10 which is arranged to wipe a wiping area 6 of the windscreen 4 which is separate from the optical surface 3 .

[0067] The wiper blade 10 carries nozzles 11 for ejecting air in the direction of the optical surface 3 .

[0068] The nozzle 11 thus delivers an air jet 12 towards the optical surface 3 .

[0069] The spray nozzle 11 is arranged at the end 14 of the wiper blade, which of its two opposite ends is closest to the optical surface 3 during cleaning.

[0070] The spray nozzle 11 comprises an air outlet orifice 15 having a converging shape in order to accelerate the fluid.

[0071] The fluid outlet orifice 15 is configured to direct the ejected fluid outside the wiping area 6 .

[0072] In other words, the fluid sprayed by the spray nozzle 11 is not used to clean the wiping area 6 .

[0073] The outlet 15 of the nozzle 11 has a fluid outlet axis FS which is tangential to the longitudinal axis WL of the wiper blade 10 .

[0074] Spray nozzle 11 may include an internal fluid passage leading to a fluid outlet 15 .

[0075] The spray nozzle 11 is formed by a part which is separate from the blade 10 and which is joined to the blade 10 , in particular by snap-fastening, screwing or welding.

[0076] The spray nozzle 11 can be removably fastened to the wiper blade 10 and is arranged in the longitudinal extension of the wiper blade 10 .

[0077] The nozzle 11 is connected to a conduit 16 for conveying fluid towards the nozzle 11 .

[0078] This pipe 16 connects the electric compressor 17 to the spray nozzle 11 .

[0079] The wiper blade 10 is attached to a wiper arm 18 , and a conduit 16 connecting the compressor 17 to the spray nozzle 11 extends a certain length along the wiper arm 18 .

[0080] The compressor 17 is arranged to compress air which is then delivered towards the spray nozzles 11. The compressor 17 is placed on a fixed support separate from the wiper blade.

[0081] The wiper arm 18 is connected to a motor 19 which is arranged to put the wiper arm into a wiping movement.

[0082] The motor 19 is coupled to an angular position sensor 20 which is arranged to determine the angle of the wiper arm 18 relative to a reference position.

[0083] In the example described, the cleaning system 1 further comprises a compressed air reservoir 22 which is supplied with compressed air from a compressor 17 placed upstream, and the spray nozzles 11 are supplied with compressed air from this compressed air reservoir 22 .

[0084] By means of this reservoir 22 acting as a buffer reservoir, the invention makes available immediately compressed air which can be conveyed very quickly towards the injection nozzles 11 .

[0085] The cleaning system 1 further comprises a solenoid valve 23 arranged to permit compressed air to circulate from the reservoir 22 towards the spray nozzle 11 in an open position and to stop compressed air from circulating from the reservoir 22 towards the spray nozzle 11 in a closed position.

[0086] This valve 23 can be controlled with a very fast reaction time, so that compressed air can be delivered to the spray nozzle 11 in a very short time. This makes it possible in particular to have a pulsed air jet.

[0087] 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 as a variant, multiple 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, which allows, for example, cycles with a cycle time of less than 20 ms, and by the fact that the pulses have a very short lifetime.

[0088] If a blower is used, it is necessary to provide that the nozzle is activated sufficiently upstream of the optical surface to be cleaned, since its start-up time may take several seconds, and that the blower remains switched on for the time required for cleaning.

[0089] The nozzle 11 is made of plastic.

[0090] The optical device 2 is an infrared camera designed to participate in an autonomous driving assistance system of a vehicle.

[0091] The device for setting the air in motion may be a blower, instead of the compressor 17. The blower is in particular a blower with radial blades.

[0092] According to one of the aspects of the present invention, the optical device protrudes from the window.

[0093] Cleaning using system 1 is carried out in the following manner:

[0094] - Using the ejection nozzle 11 , an air jet 12 is ejected in the direction of the optical surface 3 , so that the ejection of the jet 12 is controlled between an ejection start angular position (Ad) and an ejection end angular position (A+d).

[0095] In other words, the air jet 12 is not ensured during the entire operating phase of the wiper blade, but only during a limited period of time when the jet nozzle 11 is closest to the optical surface 3 to be cleaned.

[0096] For example, when the wiper blade is at an angular position of A degrees relative to the reference position, the optical surface 3 to be cleaned is closest to the nozzle, and the air jet 12 is triggered between the injection start angular position of (Ad) degrees and the injection end angular position of (A+d) degrees, where angle A is, for example, 75° or 80°, and angle d is, for example, approximately 10° or 5°.

[0097] The angular position of the wiper blade 10 is detected by an angular position detector 20 arranged at the wiper blade's motor 19. This detector 20 is, for example, of the Hall Effect type.

[0098] exist[ Figure 4 In another example of embodiment of the invention shown, the injection nozzle 11 is connected to a reservoir of additional liquid 25 (in this case windscreen washer fluid) so as to be able to be selectively supplied with only this liquid, or a mixture of this liquid and air, or only air.

[0099] The cleaning system comprises a pump 26 which is arranged to deliver liquid from a liquid reservoir 25 towards the spray nozzle 11 .

[0100] The liquid path 27 from the liquid reservoir 26 and the air path 28 from the air reservoir 22 meet in a common conduit 29 upstream of the spray nozzle 11 so that the spray nozzle can be selectively supplied with air and / or liquid.

[0101] A check valve 30 is placed on the air path 28 to prevent liquid from discharging into the air reservoir.

[0102] Another check valve 31 is placed on the liquid path 27 in order to prevent air from being discharged into the liquid reservoir 26 .

[0103] In this embodiment, only liquid, or a mixture of the liquid and air, or only air may be dispensed toward the nozzle 11 according to cleaning needs.

[0104] In an exemplary embodiment not shown, the spray nozzle is placed at a distance from the end of the blade, for example at a position on the blade that is more than 5% or 10% of the total length of the blade away from the end of the blade.

Claims

1. A system (1) for cleaning an optical surface (3) of an optical device (2), the cleaning system comprising: a wiper blade (10) for the window, the blade being arranged to wipe a wiping area (6) of the window separate from the optical surface, the blade bearing a nozzle (11) for ejecting a fluid, in particular air, in the direction of the optical surface (3), In particular, a device for setting a fluid in motion, in particular a compressor (17) or a blower, said device being intended to supply said spray nozzle (11).

2. A system as claimed in the preceding claim, wherein: The fluid is air only, or liquid only, or a mixture of liquid and air.

3. A system as claimed in any one of the preceding claims, wherein: The spray nozzle (11) is arranged at one end of the wiper blade, in particular at the end (14) of the two opposite ends of the blade which is closest to the optical surface during cleaning.

4. A system as claimed in any one of the preceding claims, wherein: The outlet (15) of the nozzle (11) has a fluid outlet axis (FS) which is tangential to the axis (WL) of the wiper blade.

5. A system as claimed in any one of the preceding claims, wherein: The cleaning system comprises at least one conduit (16) connecting a compressor (17) to the spray nozzle (11).

6. A system as claimed in any one of the preceding claims, wherein: The wiper arm is connected to a motor (19) arranged to put the wiper arm into a wiping motion, and the motor (19) is coupled to an angular position sensor (20) arranged to determine the angle of the wiper arm relative to a reference position.

7. System according to the preceding claim, wherein: The cleaning system comprises a compressed air reservoir (22) which is supplied with compressed air from the compressor (17), and the spray nozzle is supplied with compressed air from the compressed air reservoir (22).

8. The system of claim 6 or 7, wherein: The cleaning system comprises a valve (23), in particular a solenoid valve, arranged to permit compressed air to circulate from the reservoir towards the spray nozzle (11) in an open position and to stop compressed air from circulating from the reservoir towards the spray nozzle (11) in a closed position.

9. A nozzle (11) for ejecting air, said nozzle being arranged to be fastened to a wiper blade to form a cleaning system as claimed in one of the preceding claims.

10. A method for cleaning an optical surface (3) of an optical device, the cleaning method comprising the following steps: - ejecting a fluid jet (12) in the direction of the optical surface (3) using a nozzle (11) for ejecting fluid supported by a wiper blade for the window, the blade being arranged to wipe a wiping area of ​​the window separate from the optical surface.

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