U.S. patent application number 16/212928 was filed with the patent office on 2019-04-18 for integrated automotive system, pop-up nozzle assembly and remote control method for cleaning a wide-angle image sensor's exterior surface.
The applicant listed for this patent is DLHBOWLES, INC.. Invention is credited to Adam Bradbury, Zachary Kline, Praveen Pai, Alan Romack, Nicholas Watkins.
Application Number | 20190116296 16/212928 |
Document ID | / |
Family ID | 46969504 |
Filed Date | 2019-04-18 |
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United States Patent
Application |
20190116296 |
Kind Code |
A1 |
Romack; Alan ; et
al. |
April 18, 2019 |
INTEGRATED AUTOMOTIVE SYSTEM, POP-UP NOZZLE ASSEMBLY AND REMOTE
CONTROL METHOD FOR CLEANING A WIDE-ANGLE IMAGE SENSOR'S EXTERIOR
SURFACE
Abstract
A pop-up external lens washing system has an extendable aiming
fixture configured to aim a lens cleaning spray at an external lens
which is exposed to the elements and apt to become soiled with
debris. The extendable nozzle assembly is configured to be aimed
toward the external lens by the extended aiming fixture during the
washing operation only and has at least one laterally offset
washing nozzle projecting from the aiming fixture to a spray
washing fluid toward the external lens surface, spraying at a
shallow, glancing spray aiming angle to impinge upon and wash the
lens external surface.
Inventors: |
Romack; Alan; (Columbia,
MD) ; Watkins; Nicholas; (Baltimore, MD) ;
Bradbury; Adam; (Columbia, MD) ; Pai; Praveen;
(Odenton, MD) ; Kline; Zachary; (Burtonsville,
MD) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
DLHBOWLES, INC. |
CANTON |
OH |
US |
|
|
Family ID: |
46969504 |
Appl. No.: |
16/212928 |
Filed: |
December 7, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15996632 |
Jun 4, 2018 |
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16212928 |
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14086746 |
Nov 21, 2013 |
9992388 |
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15996632 |
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14004269 |
Nov 18, 2013 |
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PCT/US2012/028828 |
Mar 10, 2012 |
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14086746 |
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61451492 |
Mar 10, 2011 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B05B 1/08 20130101; B60S
1/522 20130101; B60R 11/04 20130101; B05B 1/06 20130101; B60S 1/52
20130101; H04N 5/2171 20130101; H04N 5/2257 20130101; B60S 1/0848
20130101; B60S 1/528 20130101; H04N 7/185 20130101; B60S 1/56
20130101; B08B 3/02 20130101; G02B 27/0006 20130101; G03B 17/08
20130101; H04N 5/23203 20130101; B05B 15/70 20180201 |
International
Class: |
H04N 5/217 20060101
H04N005/217; H04N 7/18 20060101 H04N007/18; B60R 11/04 20060101
B60R011/04; G03B 17/08 20060101 G03B017/08; H04N 5/232 20060101
H04N005/232; H04N 5/225 20060101 H04N005/225; B08B 3/02 20060101
B08B003/02; B60S 1/52 20060101 B60S001/52; G02B 27/00 20060101
G02B027/00; B60S 1/08 20060101 B60S001/08; B05B 1/08 20060101
B05B001/08; B05B 1/06 20060101 B05B001/06; B60S 1/56 20060101
B60S001/56 |
Claims
1. A nozzle assembly for a vehicle's external image sensor washing
system, comprising: an extendable aiming fixture having a distal
end and a proximal end and said distal end being configured to
translate between a retracted position and an extended position and
to aim a spray at an external lens for an image sensor in the
extended position; said external lens having a wide field of view
and an external lens surface with a lens perimeter and a lens
central axis projecting aligned distally from said lens surface; a
first laterally offset washing nozzle supported by said extendable
aiming fixture and configured to be aimed toward said external lens
when said aiming fixture is in the extended position; said first
laterally offset washing nozzle in fluid communication with a fluid
inlet, said first laterally offset washing nozzle being configured
to spray washing fluid toward said external lens surface aimed
across said lens central axis when said aiming fixture is in the
extended position; and wherein said first laterally offset washing
nozzle is aimed to spray along a first selected spray azimuth angle
in relation to a fixed datum on said lens perimeter when extended
and to retract said extendable aiming fixture and first laterally
offset washing nozzle to said retracted position out of a field of
view of said external lens.
2. The nozzle assembly of claim 1 wherein said external lens has a
wide angle field of view which comprises a distally projecting
solid angle of more than 120 degrees including said lens central
axis and originating within said lens perimeter.
3. The nozzle assembly of claim 2 wherein said first laterally
offset washing nozzle is configured to spray washing fluid across
said field of view when extended, spraying at a first selected
spray aiming angle in relation to the lens external surface said
first spray aiming angle being within the range bounded by
1.degree. and 20.degree. in relation to the lens external
surface
4. The nozzle assembly of claim 1 further comprising a distal cover
configured to substantially conceal the extendable aiming fixture
in the retracted position.
5. The nozzle assembly of claim 1 further comprising a cylindrical
outer body generally surrounding the extendable aiming fixture, the
cylindrical outer body in communication with the fluid inlet.
6. The nozzle assembly of claim 5 wherein a distal cover is
attached to said distal end of the extendable aiming fixture and is
configured to substantially conceal the extendable aiming fixture
in the retracted position within the cylindrical outer body.
7. The nozzle assembly of claim 5 further comprising a check valve
within the extendable aiming fixture and in communication with the
fluid inlet.
8. The nozzle assembly of claim 1, wherein said laterally offset
washing nozzle includes a fluid path defining at least a first
fluidic oscillator interaction chamber configured to operate on a
selectively actuated flow of pressurized washing fluid flowing
through said first oscillator's chamber to generate a first exhaust
flow of fluid droplets when extended; wherein said fluid inlet
receives pressurized washer fluid and is in fluid communication
with the first interaction chamber which passes the pressurized
washer fluid distally to said first laterally offset outlet nozzle
which is configured to exhaust said washer fluid from the first
interaction chamber and generate a first oscillating spray of fluid
droplets aimed toward said external lens surface and across said
field of view when extended.
9. The nozzle assembly of claim 8, wherein said first fluidic
oscillator interaction chamber includes a stepped mushroom fluidic
oscillator.
10. The nozzle assembly of claim 1, wherein said first laterally
offset washing nozzle is configured as a non-oscillating shear
nozzle configured to generate a substantially flat fan spray having
a selected spray fan angle when extended; and wherein said selected
spray fan angle is a fan angle within the range bounded by
15.degree. and 120.degree..
11. The nozzle assembly of claim 1, wherein said laterally offset
washing nozzle is a non-oscillating bug-eye nozzle configured to
generate at least one substantially solid fluid jet when
extended.
12. The nozzle assembly of claim 1, wherein said first laterally
offset washing nozzle is configured to aim said laterally offset
washing nozzle from a first selected lateral offset distance from
said objective lens' external surface when extended; and wherein
said first selected lateral offset distance from said objective
lenses external surface is within the range bounded by 15 mm and 30
mm.
13. The nozzle assembly of claim 1, wherein said first laterally
offset washing nozzle is spring biased in said retracted position
and, in response to actuation of a washer fluid pump, is
hydraulically driven to said extended position.
14. The nozzle assembly of claim 1, wherein said extendable aiming
fixture includes a projection distance between the retracted
position and the extended position is in the range of 1.5 mm to 150
mm.
15. The nozzle assembly of claim 1, wherein said first laterally
offset washing nozzle is configured to work with operating
pressures in the range of 2 psi to 80 psi for flow rates from 10
mL/minute to 1000 mL/minute.
16. A nozzle assembly for a vehicle's external image sensor washing
system, comprising: an extendable aiming fixture having a distal
end and a proximal end and said distal end being configured to
translate between a retracted position and an extended position and
to aim a spray at an external lens for an image sensor in the
extended position; said external lens having and an external lens
surface with a lens perimeter and a lens central axis projecting
aligned distally from said lens surface; a laterally offset washing
nozzle supported by said extendable aiming fixture and configured
to be aimed toward said external lens when said aiming fixture is
in the extended position; said laterally offset washing nozzle in
fluid communication with a fluid inlet, said laterally offset
washing nozzle being configured to spray washing fluid toward said
external lens surface aimed across said lens central axis when said
aiming fixture is in the extended position; a distal cover
configured to substantially conceal the extendable aiming fixture
in the retracted position; and wherein said laterally offset
washing nozzle is aimed to spray along a first selected spray
azimuth angle in relation to a fixed datum on said lens perimeter
when extended and to retract said extendable aiming fixture and
said laterally offset washing nozzle to said retracted
position.
17. The nozzle assembly of claim 16 wherein said external lens has
a wide angle field of view which comprises a distally projecting
solid angle of more than 120 degrees including said lens central
axis and originating within said lens perimeter.
18. The nozzle assembly of claim 17 wherein said first laterally
offset washing nozzle is configured to spray washing fluid across
said field of view when extended, spraying at a first selected
spray aiming angle in relation to the lens external surface said
first spray aiming angle being within the range bounded by
1.degree. and 20.degree. in relation to the lens external
surface
19. The nozzle assembly of claim 16 further comprising a
cylindrical outer body generally surrounding the extendable aiming
fixture, the cylindrical outer body in communication with the fluid
inlet.
20. The nozzle assembly of claim 19 wherein a distal cover is
attached to said distal end of the extendable aiming fixture and is
configured to substantially conceal the extendable aiming fixture
in the retracted position within the cylindrical outer body.
21. The nozzle assembly of claim 16, wherein said extendable aiming
fixture includes a projection distance between the retracted
position and the extended position is in the range of 1.5 mm to 150
mm.
22. A nozzle assembly for a vehicle's external image sensor washing
system, comprising: an extendable aiming fixture having a distal
end and a proximal end and said distal end being configured to
translate between a retracted position and an extended position and
to aim a spray at an external lens for an image sensor in the
extended position; said external lens having and an external lens
surface with a lens perimeter and a lens central axis projecting
aligned distally from said lens surface; a laterally offset washing
nozzle supported by said extendable aiming fixture and configured
to be aimed toward said external lens when said aiming fixture is
in the extended position; said laterally offset washing nozzle in
fluid communication with a fluid inlet, said laterally offset
washing nozzle being configured to spray washing fluid toward said
external lens surface aimed across said lens central axis when said
aiming fixture is in the extended position; a distal cover
configured to substantially conceal the extendable aiming fixture
in the retracted position; and wherein said laterally offset
washing nozzle is configured to retract to said retracted position
out of a field of view of said external lens.
23. The nozzle assembly of claim 22 wherein said external lens has
a wide angle field of view which comprises a distally projecting
solid angle of more than 120 degrees including said lens central
axis and originating within said lens perimeter.
24. The nozzle assembly of claim 23 wherein said first laterally
offset washing nozzle is configured to spray washing fluid across
said field of view when extended, spraying at a first selected
spray aiming angle in relation to the lens external surface said
first spray aiming angle being within the range bounded by
1.degree. and 20.degree. in relation to the lens external
surface.
25. The nozzle assembly of claim 22 wherein a distal cover is
attached to said distal end of the extendable aiming fixture and is
configured to substantially conceal the extendable aiming fixture
in the retracted position within the cylindrical outer body.
26. The nozzle assembly of claim 22, wherein said laterally offset
washing nozzle includes a fluid path defining at least a first
fluidic oscillator interaction chamber configured to operate on a
selectively actuated flow of pressurized washing fluid flowing
through said first oscillator's chamber to generate a first exhaust
flow of fluid droplets when extended; wherein said fluid inlet
receives pressurized washer fluid and is in fluid communication
with the first interaction chamber which passes the pressurized
washer fluid distally to said first laterally offset outlet nozzle
which is configured to exhaust said washer fluid from the first
interaction chamber and generate a first oscillating spray of fluid
droplets aimed toward said external lens surface and across said
field of view when extended.
27. The nozzle assembly of claim 22, wherein said laterally offset
washing nozzle is configured as a non-oscillating shear nozzle
configured to generate a substantially flat fan spray having a
selected spray fan angle when extended; and wherein said selected
spray fan angle is a fan angle within the range bounded by
15.degree. and 120.degree..
28. The nozzle assembly of claim 22, wherein said laterally offset
washing nozzle is a non-oscillating bug-eye nozzle configured to
generate at least one substantially solid fluid jet when
extended.
29. The nozzle assembly of claim 22 further comprising a
cylindrical outer body generally surrounding the extendable aiming
fixture, the cylindrical outer body in communication with the fluid
inlet.
30. The nozzle assembly of claim 29 wherein said distal cover is
attached to said distal end of the extendable aiming fixture and is
configured to substantially conceal the extendable aiming fixture
in the retracted position.
Description
PRIORITY CLAIMS AND REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. Utility
application Ser. No. 15/996,632 filed Jun. 4, 2018, which is a
continuation of U.S. Utility application Ser. No. 14/086,746 filed
on Nov. 21, 2013, which is a continuation in part of U.S. Utility
application Ser. No. 14/004,269 filed on Nov. 18, 2013, which is a
national phase application of PCT application no. PCT/US12/28828
filed Mar. 10, 2012, which claims priority to U.S. provisional
patent application No. 61/451,492 filed Mar. 10, 2011 the entire
disclosure of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
Field of the Invention
[0002] The present invention relates to automated or remotely
controlled methods and apparatus for cleaning soiled objective
lenses on wide angle or "fish-eye" video cameras or sensors when
mounted in a configuration that is exposed to dirty
environments.
Discussion of the Prior Art
[0003] External view (e.g., front bumper, side-view, rear-view or
back-up) cameras have been added to recreational vehicles and
automobiles to enhance the driver's vision and to improve safety.
Increasingly, a wide range of cars and SUVs include integrated
video cameras which generate an image for display to the driver,
operator or other occupants or users within the vehicle's
interior.
[0004] Drivers often find it difficult to move their vehicles from
parked positions when they cannot see or know what is behind the
vehicle. The recent introductions of front-bumper, side-view and
rear-view cameras in cars and SUVs by vehicle manufacturers allow
drivers to see whether obstacles surround their vehicle using a
display screen mounted either on a rear view mirror or in a
navigation system screen.
[0005] The external image sensors such as those known as back-up or
rear view cameras are typically mounted unobtrusively, and
incorporated into existing features such as the vehicle's rear name
plate. These external cameras are exposed to the vehicle's harsh
environmental surroundings and are often soiled by mud, salt spray
or dirt which accumulates on the lens. Accumulating dirt and debris
often distort the image drivers are viewing, thus creating
confusion, dissatisfaction or a safety Issue due to poor judgment
by relying on an unclear picture.
[0006] The advent of low cost, reliable imaging devices using
solid-state sensor technologies (e.g., CMOS pixel sensor
technology), combined with an Improved cost/performance ratio for
video displays capable of meeting automotive specifications, and an
increasing application rate of video monitor displays for
automotive navigation systems and the like, has lead to an
increasing use of cameras or imaging sensors designed to give the
driver a view of those areas around the vehicle which are not in
the normal direct field of view of the driver, typically referred
to as "blind spots". These areas include the region close to the
front of the vehicle, typically obscured by the forward structure
of the vehicle, the region along the passenger side of the vehicle,
the region along the driver's side of the vehicle rearward of the
driver, and the area or region immediately rearward of the vehicle
which cannot be seen directly or indirectly through the rear view
mirror system. The camera or imaging sensor may capture an image of
the rearward (or sideward or other blind spot area) field of view,
and the image may be displayed to the driver of the vehicle to
assist the driver in backing up or reversing or otherwise driving
or maneuvering the vehicle.
[0007] The use of electronic cameras in vehicle imaging systems can
significantly increase a diligent driver's knowledge of the space
immediately surrounding the vehicle prior to and during low speed
maneuvers, and thus contributes to the safe completion of such
maneuvers. It is thus known to provide a camera or imaging sensor
on a vehicle for providing an image of an exterior scene for the
driver. Such a camera may be positioned within a protective
housing, which may be closed about the camera or sensor and secured
together via fasteners or screws or the like. For example, a
metallic protective housing may be provided, such as a die cast
housing of aluminum or zinc or the like. In particular, for camera
sensors mounted on the exterior of a vehicle, protection against
environmental effects, such as rain, snow, road splash and/or the
like, and physical protection, such as against road debris, dirt,
dust, and/or the like, is important. Thus, for example, in known
exterior camera sensor mounts, a butyl seal, such as a hot
dispensed butyl seal, or an O-ring or other sealing member or
material or the like, has been provided between the parts of the
housing to assist in sealing the housing to prevent water or other
contaminants from entering the housing and damaging the camera or
sensor positioned therein. However, such housings typically do not
provide a substantially water tight seal, and water droplets thus
may enter the housing. Furthermore, any excessive vibration of the
camera sensor, due to its placement (such as at the exterior of the
vehicle), may lead to an undesirable instability of the image
displayed to the driver of the vehicle. Also, such cameras or
sensors are costly to manufacture and to implement on the
vehicles.
[0008] Such vehicle vision systems often position a camera or
imaging sensor at an exterior portion of a vehicle to capture an
image of an exterior scene. The cameras, particularly the cameras
for rearward vision systems, are thus typically placed or mounted
in a location that tends to get a high dirt buildup on the camera
and/or lens of the camera, with no easy way of cleaning the camera
and/or lens. In order to reduce the dirt or moisture buildup on the
lenses of such cameras, prior art developers proposed using
hydrophilic or hydrophobic coatings on the lenses. However, the use
of such a hydrophilic or hydrophobic coating on the lens is not
typically effective due to the lack of air flow across the lens,
especially within a sealed housing. It has also been proposed to
use heating devices or elements to reduce moisture on the lenses,
within the sealed housing. However, the use of a heated lens in
such applications, while reducing condensation and misting on the
lens, may promote the forming of a film on the lens due to
contamination that may be present in the moisture or water. Also,
the appearance of such cameras on the rearward portion of vehicles
is often a problem for styling of the vehicle. See, for example,
prior art U.S. Pat. No. 7,965,336 to Bingle, et al. which discloses
a camera module with a plastic housing that houses an image sensor,
which is operable to capture Images of a scene occurring exteriorly
of the vehicle. Bingle's camera housing assembly is welded together
with the image sensor and associated components within enclosed the
plastic housing, and includes a "breathable" ventilation portion
that is at least partially permeable to water vapor to allow
emission of internal water vapor substantially precluding passage
of water droplets and other contaminants, and so Bingle's design
seeks to minimize problems arising from fluid impacting or
accumulating within the housing.
[0009] Bingle also seeks to use coated lenses to keep the objective
lenses' view clear, and Bingle's housing or cover 22 is optionally
be coated with an anti-wetting property such as via a hydrophobic
coating (or stack of coatings), such as is disclosed in U.S. Pat.
No. 5,724,187. Bingle notes that a hydrophobic property on the
outermost surface of the cover can be achieved by a variety of
means, such as by use of organic and inorganic coatings or by
utilizing diamond-like carbon coatings. But Bingle and others do
not propose actually taking any affirmative action to remove road
debris (e.g., accumulated dirt, dust, mud, road salt or other
built-up debris) apart from using such coatings or surface
treatments.
[0010] Based on consumer preference and at least a perceived
improved ability to extract information from the image, it is
desired to present an image to the driver that is representative of
the exterior scene as perceived by normal human vision. It is also
desirable that a vehicle's imaging devices or systems be useful in
all conditions, and particularly in all weather and lighting
conditions. However, it is often difficult to provide an imaging
sensor which is capable of providing a clear image in poor weather,
especially while driving. This is because conventional imaging
systems typically have difficulty resolving scene information when
the camera's objective lens is partially obstructed by accumulated
debris (e.g., accumulated dirt, dust, mud, road salt or other
built-up debris).
[0011] In order to have effective use of the camera-based
visibility systems in all weather conditions, it is desirable to
have an effective method of keeping the camera lens (or the housing
surface protecting the objective lens) clean, but the potentially
deleterious effects of moisture noted in Bingle remain. When
driving or operating a vehicle during bad weather, drivers are
especially reluctant to exit the vehicle to find and inspect the
camera's lens.
[0012] This reluctance likely explains why the inventors of U.S.
Pat. No. 6,834,904 (to Vaitus et al) included a "Nozzle" 92 "in
close proximity to" lens 84 for the vehicle's camera or vision unit
71. The Vaitus '904 patent generally discloses the structure and
method for mounting a "Vehicle Liftgate with Component Module
Applique" wherein applique module 50 is adapted for attachment to
vehicle liftgate 20 and, as shown in Vaitus' FIG. 2, module 50
includes a nozzle 92 which receives fluid from conduit 94, but, as
noted in the description at Col 5, lines 5-25, "cleaning of lens 84
may be implemented in other ways" such as hydrophobic lens
coatings. It appears that the module and nozzle arrangement
described so indifferently in the Vaitus '904 patent was not deemed
to be a practicable or effective solution meriting further
development, and so appears to have been ignored.
[0013] Increasingly on modern vehicles, cameras or other sensors
such as infrared image sensors are incorporated to provide
additional information to the driver. Many of these sensing devices
can become soiled and obstructed by dirt and debris common in the
driving environment, eventually causing deterioration in the
efficacy of the sensing device or possibly rendering it unusable,
or providing an undesirable appearance. It is therefore desirable
to periodically wash these sensing devices to reduce or eliminate
the buildup of these obstructions. However, there are restrictions
which are unique to certain sensor wash applications which limit
use of traditional washer nozzles. Sensors may be located on or
near the vehicle centerline, in close proximity to branding badges
or other cosmetically important features on the vehicle, and it is
undesirable to add a visible washer nozzle in this aesthetically
important area. Another restriction is that sensors may have very
wide fields of view, up to or exceeding 180.degree., so that a
traditional lens washer nozzle configuration would have to be
within the sensor's field of view in order to be able to direct
fluid onto the sensor surface at an angle which would provide
acceptable cleaning.
[0014] Being located within the sensor's field of view may block a
significant portion of area the sensor would otherwise be capable
of monitoring. A third constraint which affects sensor wash
applications is that the sensor may frequently be located on an
area of the vehicle which sees higher levels of contamination than
do typical washer nozzle mounting locations, such as on the front
grill or the rear lift gate. Washer nozzles in these locations may
be at a higher risk of being clogged by the same material which is
obscuring the sensor. There is a need, therefore, for a convenient,
effective and unobtrusive system and method for cleaning an
exterior objective lens or wide-angle sensor's exterior surface,
and preferably by remote control.
OBJECTS AND SUMMARY OF THE INVENTION
[0015] Accordingly, it is an object of the present invention to
overcome the above mentioned difficulties by providing a
convenient, effective and unobtrusive system and method for
cleaning an exterior objective lens or wide-angle sensor's exterior
surface to remove accumulated debris (e.g., accumulated dirt, dust,
mud, road salt or other built-up debris).
[0016] In accordance with an exemplary embodiment of the present
invention, an external lens washing system has a number of
configurations including a pop-up aiming fixture configured to
extend beyond and then spray external lens or sensor surface which
is exposed to the elements and apt to become soiled with debris. A
nozzle assembly is configured to be supported and aimed toward the
external lens by the aiming fixture and has at least one laterally
offset pop-up washing nozzle assembly which is configured to
selectively project from the aiming fixture to a spray washing
fluid toward the external lens or sensor surface, spraying at a
selected shallow, glancing spray aiming angle to impinge upon and
wash the lens external surface.
[0017] Optionally, an integrated image sensor and lens washing
assembly is configured for use with a remote control method for
cleaning an exterior objective lens surface and includes a sealed
image sensor housing assembly including an integral, remotely
controllable lens cleaning system with an optimized configuration
for aiming one or more cleansing sprays from one or more laterally
offset fluidic oscillators.
[0018] The integrated automotive system uses one or more aimed
sprays to clean an exterior objective lens surface and the method
enables the driver to determine when to clean a soiled
external-view camera's objective lens, so the driver can ensure
that the lens is adequately cleaned of accumulated debris (e.g.,
accumulated dirt, dust, mud, road salt or other built-up debris)
before moving.
[0019] The system of the present invention provides an image sensor
housing assembly including an integral, remotely controllable lens
cleaning system with an optimized configuration for aiming one or
more cleaning sprays of selected fluidic oscillators at the
housing's transparent objective lens protective cover to safely and
quickly remove accumulated debris (e.g., accumulated dirt, dust,
mud, road salt or other built-up debris) and minimize the
likelihood that vision obstructing debris or washer fluid droplets
remain in the camera's field of view.
[0020] In a preferred embodiment of the lens cleaning system of the
present invention, low flow rate fluidic circuit nozzles are
configured and aimed in a manner which uses very little washing
fluid. As a result, integrating the system of the present invention
in a vehicle uses less washing fluid from the vehicle's washer
fluid bottle and provides bottle-cleanings savings, conservation of
fluid, and conservation of pressure. Conservation of washer fluid
pressure is especially important when the camera lens cleaning
system is integrated into an existing vehicle design's front wash
system, where the camera lens washing system must function without
detrimentally affecting front glass cleaning, especially under
dynamic driving conditions, where the front glass cleaning system's
performance is highly sensitive to fluid pressure. The system and
method of the present invention is not limited to use with low flow
rate nozzles exclusively, however. Applicants have prototyped a
relatively high flow rate nozzle assembly on an exemplary system
and it works well, although the camera's image is somewhat
compromised when actually spraying fluid and washing. It appears
that the low flow rate is best accomplished thru a selected fluidic
circuit geometry which allows washing fluid, since droplet size
should remain larger when compared to a shear nozzle.
[0021] Applicants' prototype development work has revealed that a
certain lens washing nozzle configuration and aiming orientation
presents a surprisingly effective and evenly distributed
oscillating spray pattern with the following benefits:
[0022] Allows for nearly flush mounting to the camera's distal or
objective lens surface, which means the camera-plus-washer package
or assembly does not get longer and interfere, or interfere as
much, with camera viewing angles as a directed impact nozzle
configuration would; and
[0023] can be packaged in really close to keep the overall width of
the camera-plus-washer package from growing wider and larger;
(e.g., a wider or larger diameter bug-eye lens would likely need to
have the nozzle spray originate above the lens, angled down, and
pushed away from the center line to avoid sight lines, although
this would result in a wider and longer package).
[0024] The applicants have discovered that directly spraying at a
narrow, glancing angle nearly parallel to the objective lens
assembly's external surface results in less washer fluid or water
remaining on the lens after conclusion of spraying and prevents
water droplets from forming and remaining on the lens and
obstructing the view after washing. In prototype development
experiments, a more nearly on-lens axis or direct impingement spray
method was discovered to leave view-obstructing droplets behind. In
other prototype development work, applicants have also noted that
shear nozzles work surprisingly well.
[0025] Broadly speaking, the integrated automotive system and
nozzle assembly of the present invention is configured for use with
a remote control method for cleaning an exterior objective lens
surface includes a sealed image sensor housing assembly including
an integral, remotely controllable lens cleaning system with an
optimized configuration for aiming one or more cleansing sprays
from selected fluidic oscillators at the housing's transparent
objective lens protective cover.
[0026] For wide angle cameras and sensors, a selectively projecting
embodiment is configured to extend, when washing and retract (out
of the camera's or sensor's field of view) when not washing. The
selectively projecting ("pop-up") embodiment of the present
invention is uniquely well suited to solving these problems. By
locating the washer nozzle on a hydraulic cylinder, the origin of
the wash spray is allowed to be retracted when not in use, reducing
or eliminating field of view issues and allowing the nozzle orifice
to be shielded from contamination which might otherwise clog it.
Additionally the nozzle may be masked by a cap or other feature
which hides the nozzle and allows it to be placed in a cosmetically
important area without negatively affecting aesthetics. When
activated, the nozzle extends such that an acceptable spray angle
of incidence can be achieved to allow efficient and effective
cleaning of the sensor, minimizing the use of washer fluid as well
as minimizing the amount of time that the nozzle is visible to the
sensor or to the end user.
[0027] The selectively projecting ("pop-up") embodiment of the
present invention has a check valve located within the nozzle, so
the waste of pumped washing fluid is minimized. A nozzle without a
check valve would begin spraying while still in the retracted
position, wasting fluid during the time the nozzle is extending as
well as causing fluid to be sprayed at areas where fluid may not be
desirable. By including the check valve within the extending
portion of the device, fluid cannot escape until the device is
partially or fully extended, reducing or eliminating overspray.
Retention of the assembly is controlled by snap tabs which are an
extension of the outer body wall, so overall package size is
minimized. Other embodiments would use bulkier retention features,
taking up valuable packaging space. The nozzle housing is
preferably an integral part of the hydraulic cylinder which has
sliding contact with the inner body, so overall packaging size is
reduced and the number of components is reduced when compared to
another embodiment which has the nozzle housing just on the end of
the hydraulic cylinder.
[0028] By placing the o-ring seal above the plane of the lip seal
in the fully extended position, the overall diameter of the pop-up
washing nozzle assembly is minimized compared to an embodiment
which seals lower down, because the size of the inner diameter
(I.D.) of the o-ring is close to the outer diameter (O.D.)
dimension of the lip seal. If the o-ring were located lower in the
assembly, a larger o-ring and overall package size would be
required to maintain adequate wall thickness of the inner body in
the o-ring seal area and keep the same lip seal outer diameter.
[0029] For any of the washer systems of the present invention, in
use, a driver, user or operator views the image generated by the
external camera or image sensor on an interior video display and
decides whether and when to clean the external camera's objective
lens cover's surface to remove accumulated debris (e.g.,
accumulated dirt, dust, mud, road salt or other built-up debris).
An interior remote actuation control input (e.g., button or
momentary contact switch) is provided within the operator's easy
reach for convenient use in cleaning the lens, and the operator
actuates the system and causes the cleansing spray to begin while
viewing the image sensor's output on the video display, stopping
actuation of the system when the operator deems the image sensor's
view to be satisfactory.
[0030] The above and still further objects, features and advantages
of the present invention will become apparent upon consideration of
the following detailed description of a specific embodiment
thereof, particularly when taken in conjunction with the
accompanying drawings, wherein like reference numerals in the
various figures are utilized to designate like components.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] FIG. 1A, is a rear perspective view of a vehicle having an
imaging system or back-up camera system as disclosed in U.S. Pat.
No. 7,965,336 (to Bingle et al), in accordance with the Prior
Art.
[0032] FIG. 1B is a plan view of the vehicle of FIG. 1A.
[0033] FIG. 1C is an end elevation of a sealed solid-state image
sensor or camera module as disclosed in U.S. Pat. No. 7,965,336, in
accordance with the Prior Art.
[0034] FIG. 1D is a sectional view of the camera module of FIG. 1C,
taken along the line D-D.
[0035] FIG. 2 is a schematic diagram illustrating an automotive
imaging system with a camera housing and integrated nozzle assembly
configured for use with a remote control method for cleaning the
imaging system's exterior objective lens surface, in accordance
with the present invention.
[0036] FIGS. 3A-3D illustrate a configuration of and displayed
performance of the Imaging system, camera housing and an aimed
nozzle assembly, in accordance with the present invention.
[0037] FIG. 4 is a schematic diagram illustrating a fluidic spray
from an embodiment of the camera housing and integrated nozzle
assembly of FIG. 3, in accordance with the present invention.
[0038] FIGS. 5A and 5B are schematic diagrams illustrating a
perspective view and a side view of a fluid sheet sprayed by an
aimed nozzle assembly configured for use with the method for
cleaning an imaging system's exterior objective lens surface, in
accordance with the present invention.
[0039] FIGS. 6A and 6B are schematic diagrams illustrating a top or
plan view and a side view of an embodiment with opposing aimed
washer fluid jets spreading fluid over a convex objective lens
surface when sprayed by a washing system configured in accordance
with the present invention.
[0040] FIG. 7 is a schematic diagram illustrating another
automotive imaging system with a camera washing nozzle assembly
configured for use with the remote control method for cleaning the
imaging system's exterior objective lens surface, in accordance
with the present invention.
[0041] FIG. 8 is a schematic diagram illustrating yet another
automotive imaging system configuration with a camera washing
nozzle assembly configured for use with the remote control method
for cleaning the imaging system's exterior objective lens surface,
in accordance with the present invention.
[0042] FIG. 9 is a perspective view illustrating aimed spray
orientation for another camera nozzle assembly configured for use
with the method for cleaning the imaging system's exterior
objective lens surface, in accordance with the present
invention.
[0043] FIG. 10 is a side view illustrating aimed spray fan angle
and incidence angle for the system and nozzle assembly of FIG. 9,
in accordance with the present invention.
[0044] FIG. 11 is a perspective view illustrating range of fluidic
oscillator nozzle mounting distances for the system and nozzle
assembly of FIGS. 9 and 10, in accordance with the present
invention.
[0045] FIGS. 12A and 12B illustrate the fluidic circuit features of
an exemplary stepped mushroom fluid oscillator for use with an
external camera lens cleaning nozzle assembly of the present
invention.
[0046] FIGS. 13A-13C illustrate another embodiment for the external
lens washing system and nozzle assembly of the present
invention.
[0047] FIGS. 14A-14C are cross sectional views illustrating another
embodiment for the system and nozzle assembly of the present
invention, wherein a pop-up nozzle assembly is configured to wash
the external surface of a wide angle image sensor.
[0048] FIGS. 15A and 15B illustrate an exploded perspective view of
the internal components of pop-up nozzle assembly of FIGS.
14A-14C.
[0049] FIGS. 16A-16C are cross sectional views illustrating the
sequence of operating states for the pop-up nozzle assembly of
FIGS. 14A-14C.
[0050] FIG. 17 is a cross sectional view in elevation illustrating
the pop-up nozzle assembly of FIGS. 14A-16C, configured to wash the
external surface of a wide angle image sensor.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0051] Vehicle Imaging System and Camera Module Nomenclature
[0052] In order to provide an exemplary context and basic
nomenclature, we refer initially to FIGS. 1A-1D, illustrating a
prior art imaging system for a vehicle and a camera module as
disclosed in U.S. Pat. No. 7,965,338 (to Bingle et al). This
overview will be useful for establishing nomenclature and
automotive industry standard terminology, in accordance with the
Prior Art.
[0053] Referring now to FIGS. 1A-1D, an image capture system or
imaging or vision system 7 is positioned at a vehicle 8, such as at
a rearward exterior portion 8a of the vehicle 8, and is operable to
capture an image of a scene occurring interiorly or exteriorly of
the vehicle, such as rearwardly of the vehicle, and to display the
image at a display or display system 9a of the vehicle which is
viewable by a driver or occupant of the vehicle (see, e.g., FIGS.
1A and 1B). Imaging system 7 includes a camera module 10, which is
mountable on, at or in the vehicle to receive an Image of a scene
occurring exteriorly or Interiorly of the vehicle, and a control 9b
that is operable to process images captured by an image sensor 18
of camera module 10. Camera module 10 includes a plastic camera
housing 11 and a metallic protective shield or casing 16 (see FIGS.
1C & 1D).
[0054] Camera housing 11 includes a camera housing portion 12 and a
connector portion 14, which mate or join together and are
preferably laser welded or sonic welded together to substantially
seal the housing 11 to substantially limit or prevent water
intrusion or other contaminants from entering the housing, as
discussed below.
[0055] Housing 11 of camera module 10 substantially encases a
camera or image sensor or sensing device 18 (FIGS. 1C and 1D),
which is operable to capture an image of the scene occurring
exteriorly or interiorly of the vehicle, depending on the
particular application of camera module 10. Housing 11 also
includes a cover portion 20 at an end of camera housing portion 12.
Cover portion 20 provides a transparent cover plate 22 which allows
the image of the scene exteriorly or interiorly of the vehicle to
pass therethrough and into housing 11 to camera image sensor 18.
Camera module 10 may include the protective shield 16, which
substantially encases camera housing portion 12 and a portion of
connector portion 14, thereby substantially limiting or reducing
electronic noise going into or out of the camera module and/or
protecting the plastic housing 11 from damage due to impact or the
like with various items or debris that may be encountered at the
exterior of the vehicle.
[0056] Camera module 10 provides a camera image sensor or image
capture device 18 for capturing an image of a scene occurring
exteriorly or interiorly of a vehicle. The captured image may be
communicated to a display or display system 9a which is operable to
display the image to a driver of the vehicle. The camera or imaging
sensor 18 useful with the present invention may comprise an imaging
array sensor, such as a CMOS sensor or a CCD sensor or the like,
such as disclosed in U.S. Pat. Nos. 5,550,677; 5,670,935;
5,796,094; 6,097,023, and 7,339,149. Camera module 10 and imaging
sensor 18 may be implemented and operated in connection with
various vehicular vision systems, and/or may be operable utilizing
the principles of such other vehicular systems, such as a vehicle
vision system, such as a forwardly, sidewardly or rearwardly
directed vehicle vision system utilizing principles disclosed in
U.S. Pat. Nos. 5,550,677; 5,670,935; 5,760,962; 5,877,897;
5,949,331; 6,222,447; 6,302,545; 6,396,397; 6,498,620; 6,523,964;
6,611,202; and 6,201,642, and/or a trailer hitching aid or tow
check system, such as the type disclosed in U.S. Pat. No.
7,005,974, a reverse or sideward imaging system, such as for a lane
change assistance system or lane departure warning system, such as
the type disclosed in U.S. Pat. No. 7,038,577, a system for
determining a distance to a leading or trailing vehicle or object,
such as a system utilizing the principles disclosed in U.S. Pat.
No. 6,396,397 or the like.
[0057] For example, the camera or sensor may comprise a LM9618
Monochrome CMOS Image Sensor or a LM9628 Color CMOS Image Sensor,
both of which are commercially available from National
Semiconductor. Other suitable cameras or sensors from other vendors
(e.g., Sony.RTM., Panasonic.RTM., Magna.TM. and others) may be
implemented with the camera module.
[0058] Although shown at a rear portion 8a of vehicle 8, camera 18
and camera module 10 may be positioned at any suitable location on
vehicle 8, such as within a rear panel or portion of the vehicle, a
side panel or portion of the vehicle, a license plate mounting area
of the vehicle, an exterior mirror assembly of the vehicle, an
interior rearview mirror assembly of the vehicle or any other
location where the camera may be positioned and oriented to provide
the desired view of the scene occurring exteriorly or interiorly of
the vehicle. The camera module 10 is particularly suited for use as
an exterior camera module. The image captured by the camera may be
displayed at a display screen or the like positioned within the
cabin of the vehicle, such as at an Interior rearview mirror
assembly (such as disclosed in U.S. Pat. No. 6,690,268), or
elsewhere at or within the vehicle cabin, such as by using the
principles disclosed in U.S. Pat. Nos. 5,550,677; 5,670,935;
5,796,094; 6,097,023 and 6,201,642, and/or 6,717,610.
[0059] As best shown in FIGS. 1C and 1D, camera housing portion 12
includes a generally cylindrical portion 12a extending outwardly
from a base portion 12b. Camera housing portion 12 comprises a
molded plastic component and may include a pair of heater terminals
or elements 30a, 30b insert molded within and/or along the walls of
cylindrical portion 12a. Cylindrical portion 12A receives a lens or
optic system 24 therein, which functions to focus the image onto
camera or sensor 18, which is positioned at a circuit board 26
mounted within the base portion 12B of camera housing portion
12.
[0060] Lens system 24 is positioned within cylindrical portion 12a
of camera portion 12 to receive light from the exterior or interior
scene through cover 22 at end 12c of camera portion 12. Lens system
24 is mounted to, such as via threaded engagement with, camera
cover or housing 28, which functions to substantially cover or
encase camera or sensor 18 to substantially prevent or limit
incident light from being received by camera 18 and interfering
with the image received by camera 18 through cover 22 and lens
system 24. The lens system 24 may be any small lens or lens system
which may focus an image of the scene exteriorly of the camera
module onto the camera or image sensor 18, such as, for example,
the types disclosed in U.S. Pat. No. 6,201,642 or 6,757,109. The
lens system 24 may provide a wide-angle field of view, such as
approximately 120 degrees or more (as shown in FIG. 1A).
[0061] Cover portion 20 is mounted at an outer end 12c of camera
housing portion 12 opposite from base portion 12b, as shown in
FIGS. 1C and 1D. Cover portion 20 includes an outer circumferential
ring or cover retainer 20a, which engages an outer surface of
transparent cover 22 and functions to retain transparent cover 22
in position at the end 12c of the cylindrical portion 12a of camera
receiving portion 12. Preferably, circumferential ring 20a is laser
welded or sonic welded or otherwise joined or bonded to outer end
12c of cylindrical portion 12a of camera receiving portion 12 to
substantially seal and secures cover portion 20 onto camera
receiving portion 12, and may limit or substantially preclude any
water intrusion or contaminant intrusion into the camera receiving
portion at the outer end 12c.
[0062] In the illustrated embodiment, base portion 12b is generally
square and defines a generally square mating edge 12e around the
base portion 12b for mating and securing to a corresponding edge
14g of connector portion 14 at joint 13. Base portion 12b receives
circuit board 26 and camera 18 therein, while a camera housing or
shield 28 and lens or lens system 24 extend into cylindrical
portion 12a of camera portion 12 to receive the image through
transparent cover 22.
[0063] Connector portion 14 of housing 11 is a molded plastic
component and includes a connector terminal or connector 14a, such
as a multi-pin snap-on connector or the like, extending from a base
portion 14b. Base portion 14b is formed (such as in a square shape
as shown in the illustrated embodiment) to substantially and
uniformly mate or connect to base portion 12b of camera housing 12,
as can be seen with reference to FIGS. 1C and 1D. The base portions
12b and 14b mate together and define a pocket or space for
receiving and securing circuit board 26 therein. Base portions 14b
and 12b may be laser welded or sonic welded together at their
mating joint or connection 13. Laser or sonic welding of the joint
melts the plastic edges or seams together to substantially
hermetically seal housing 11 to prevent water intrusion or other
contaminant intrusion into housing 11 of camera module 10.
Optionally, and less desirably, the base portions may be otherwise
joined or substantially sealed together (such as via suitable
adhesives and/or sealants). The module may optionally include a
vented portion or semi-permeable membrane to vent the module's
interior. The base portions 12b and 14b may further include
mounting tabs or flanges 12d, which extend outwardly from base
portion 12b. Mounting tabs 12d are generally aligned with one
another when the base portions are secured together and include an
aperture therethrough for mounting the camera module 10 at or to
the vehicle 8 via suitable fasteners or the like (not shown).
Although shown as having generally square-shaped mating portions,
connector portion 14 and camera portion 12 may have other shaped
mating portions or surfaces.
[0064] Multi-pin connector 14a extends from base portion 14b and
includes a plurality of pins or terminals 14c for electrically
connecting camera module 10 with a connector (not shown) connected
with the wiring harness or cables of the vehicle. For example, one
end 14d of terminals 14c may connect to circuit board 26, while the
other end 14e of terminals 14c connects to the corresponding
connector of the vehicle. The corresponding connector may partially
receive the ends 14e of pins or terminals 14c at multi-pin
connector 14a and may snap together with multi-pin connector 14a
via a snap connection or the like. As best shown in FIG. 1D, ends
14d of terminals 14c protrude or extend from connector portion 14,
such that the ends 14d may be received within corresponding
openings or apertures 26c in circuit board 26 when housing portion
11 is assembled.
[0065] As shown in FIG. 1D, connector portion 14 may provide a
generally straight multi-pin connector extending longitudinally
from the base portion of the housing 11. However, other shapes of
connectors, such as angled connectors or bent connectors or the
like, may be implemented, depending on the particular application
of the camera module.
[0066] Optionally, camera module 10 may comprise a substantially
hermetically sealed module, such that water intrusion into the
module is limited or substantially precluded. Base portion 12b of
camera housing portion 12 and base portion 14b of connector portion
14 are correspondingly formed so as to substantially mate or join
together at their mating seam 13, whereby the portions may be laser
welded or sonic welded together or otherwise joined, while cover
portion 20 is also laser welded or sonic welded or otherwise
secured and substantially sealed at the opposite end 12c of camera
portion 12, in order to substantially seal the camera housing.
Laser or sonic welding techniques are preferred so as to join the
materials at a state where they are able to re-flow, either via
heat, vibration or other means, such that the materials re-flow and
cross-link and become a unitary part. Such joining results in a
substantially hermetically sealed camera module. Additionally, the
pores in the plastic as well as any voids around the insert molded
pins and stampings may be sealed with a Loctite.RTM. brand sealing
material or other suitable sealing material, to further limit or
substantially preclude entry of water droplets and/or water vapor
into the housing of the substantially sealed camera module 10.
[0067] Circuit board 26 includes a camera mounting circuit board
26a, which is connected to a connector receiving circuit board 26b
via a multi-wire ribbon wire or the like (not shown). Camera
mounting circuit board 26a is mounted or secured to the base
portion 12b of camera portion 12, while connector circuit board 26b
is mounted or secured to the base portion 14b of connector portion
14. Camera or image sensor 18 is mounted at a surface of camera
circuit board 26a, and is substantially encased at circuit board
26a by camera cover 28 and lens 24 (FIGS. 1C and 1D). Camera
circuit board 26a includes a pair of apertures 26c for receiving
ends 30c of terminals 30a, 30b. Likewise, connector circuit board
26b includes a plurality of openings or apertures 26d for receiving
ends 14d of connector terminals 14c therethrough. The ends of the
pins or terminals may be soldered in place in their respective
openings. After all of the connections are made, the housing may be
folded to its closed position and laser welded or sonic welded
together or otherwise joined or bonded together to substantially
seal the circuit board within the housing.
[0068] Optionally, the exterior surface of cover 22 (which may be
exposed to the atmosphere exterior of the camera module) may be
coated with an anti-wetting property such as via a hydrophilic
coating (or stack of coatings), such as is disclosed in U.S. Pat.
Nos. 6,193,378; 5,854,708; 6,071,606; and 6,013,372. Also, or
otherwise, the exterior or outermost surface of cover 22 may
optionally be coated with an anti-wetting property such as via a
hydrophobic coating (or stack of coatings), such as is disclosed in
U.S. Pat. No. 5,724,187. Such hydrophobic property on the outermost
surface of the cover can be achieved by a variety of means, such as
by use of organic and Inorganic coatings utilizing a silicone
moeity (for example, a urethane incorporating silicone moeities) or
by utilizing diamond-like carbon coatings. For example, long-term
stable water-repellent and oil-repellent ultra-hydrophobic
coatings, such as described in WIPO PCT publication Nos. WO0192179
and WO0162682, can be disposed on the exterior surface of the
cover. Such ultra-hydrophobic layers comprise a nano structured
surface covered with a hydrophobic agent which is supplied by an
underlying replenishment layer (such as is described in Classen et
al., "Towards a True `Non-Clean` Property: Highly Durable
Ultra-Hydrophobic Coating for Optical Applications", ECC 2002
"Smart Coatings" Proceedings, 2002, 181-190). For enablement and
completeness of disclosure, all of the foregoing references are
incorporated herein by reference.
[0069] In FIGS. 1A-1D, camera module 10 is shown to Include a
protective conductive shield or casing 16 which partially encases
the plastic housing 11 and functions to limit or reduce electronic
noise which may enter or exit camera module 10 and may protect the
plastic housing from damage from impact of various items or debris
which the camera module may encounter at the exterior portion of
the vehicle.
[0070] The protective shield or casing 16 includes a pair of casing
portions 16a (one of which is shown in FIGS. 1C and 1D). Each of
the casing portions 16a partially encases about half of the plastic
housing 11 of camera module 10 and partially overlaps the other of
the casing portion 16a, to substantially encase the plastic housing
within protective shield 16. Each of the portions 16a includes a
slot 16b for receiving the mounting tabs 12d therethrough for
mounting the camera module at the desired location at the vehicle.
Each casing portion 16a includes overlapping portions 16c which
overlap an edge of the other casing portion 16a to assemble the
casing 16 around the plastic housing 11. The casing portions 16a
may be welded, crimped, adhered, banded, or otherwise joined or
secured together about the plastic housing 11, in order to encase
the housing 11. Preferably, protective shield 16 comprises a
metallic shield and contacts ground terminal 30b of heating device
30 at the exterior surface of the cylindrical portion 12a of camera
receiving portion 12 and, thus, may be grounded to the heating
device and/or the camera module or unit via the ground terminal
30b. Protective shield 16 may comprise a stamped metal shielding or
may be formed by vacuum metalizing a shield layer over the plastic
housing 11, or may comprise a foil or the like.
[0071] Camera Housing and Integrated Washing System Nozzle
Assembly.
[0072] Referring now to FIGS. 2-13D, an exemplary embodiment of the
present invention has an Integrated camera housing and washing
system nozzle assembly 110 and FIGS. 2-13D illustrate the method
for cleaning a camera's or image sensor's exterior objective lens
surface (e.g., 122), in accordance with the present invention.
Integrated camera housing and nozzle assembly 110 preferably
includes one or more laterally offset nozzles 130, 132 configured
and aimed to generate and an oscillating spray to clean exterior
objective lens surface 122, and allows a vehicle's driver, user or
operator to use interior display 9a to determine whether
external-view camera objective lens surface or cover 122 is
occluded by or covered with accumulated debris (e.g., accumulated
dirt, dust, mud, road salt or other built-up debris, not shown).
The driver will want to ensure that the external objective lens
surface 122 is adequately cleaned before moving the vehicle 8.
Laterally offset nozzles 130, 132 are preferably entirely out of
the image sensor's distal field of view and are configured and
aimed to spray washing fluid onto external objective lens surface
122 at a narrow, glancing angle which is preferably nearly parallel
to the objective lens assembly's external surface 122, as will be
described in more detail below.
[0073] Camera housing and nozzle assembly 110, as illustrated in
FIG. 2 has an external housing 111 with a hollow interior enclosed
within fluid-impermeable sidewalls and a substantially fluid
impermeable sealed camera module 112 is carried within the interior
of housing 111 which defines an enclosure with an interior lumen or
fluid path 140 preferably configured to define least one fluidic
oscillator that operates on a selectively actuated flow of
pressurized fluid flowing through the oscillator's interior 140 to
generate an exhaust flow in the form of an oscillating spray of
fluid droplets (not shown), as will be described below. The
oscillator in fluid path 140 comprises a proximal inlet 142 for
pressurized washer fluid, an interaction chamber defined within the
housing fluid path 140 receives the pressurized washer fluid from
inlet 142 and passes the pressurized fluid distally to outlets or
nozzles 130, 132 so an oscillating washer fluid spray exhausts from
the interaction chamber 140.
[0074] Fluidic oscillators can provide a wide range of liquid spray
patterns by cyclically deflecting a fluid jet. The operation of
most fluidic oscillators is characterized by the cyclic deflection
of a fluid jet without the use of mechanical moving parts.
Consequently, an advantage of fluidic oscillators is that they
provide an oscillating spray of fluid droplets but don't require
moving parts and so are not subject to the wear and tear which
adversely affects the reliability and operation of other
oscillating spray devices. Alternatively, camera housing and nozzle
assembly 110 may have a featureless hollow interior lumen defining
a cylindrical or annular fluid path from proximal fluid inlet 142
to an open distal shear nozzle adapted to spray external objective
lens surface 122 with washer fluid at a narrow, glancing angle
nearly parallel to the objective lens assembly's external surface
122.
[0075] Camera housing and nozzle assembly 110 preferably includes
at least one "stepped mushroom" fluidic oscillator of the type
described in commonly owned U.S. Pat. No. 7,267,290 (Gopalan et
al), the entire disclosure of which is incorporated herein by
reference. As shown in FIGS. 12A and 12B (and described more fully
in the incorporated '290 patent's description) the stepped mushroom
fluidic oscillator is defined by inwardly projecting features (not
shown in FIG. 2) acting on the fluid flowing distally in fluid path
140 which defines the interaction chamber within the housing fluid
path 140. Washing fluid passes from proximal fluid inlet 142
distally into the interaction chamber 140 and the pressurized
oscillating fluid jets pass to outlets or nozzles 130, 132 from
which an oscillating washer fluid spray projects laterally onto
objective lens surface 122. The preferred spray flow rate is
approximately 200 ml/min per nozzle at 18 psi, and the spray
thickness (i.e., which is seen in the plane transverse to the
spray's fan angle plane as shown in FIG. 5B) is approximately 2
degrees.
[0076] As illustrated in FIG. 2, external lens washing system with
housing and nozzle assembly 110 provides a substantially rigid
aiming fixture (i.e., housing 111) having a distal side and a
proximal side and being configured to support and constrain
external lens 122 which is exposed toward the distal side. External
lens 122 has an external lens surface with a lens perimeter and a
lens central axis 150 projecting distally from the lens surface,
wherein a lens field of view is defined as a distally projecting
solid angle (e.g., a truncated cone or pyramid, not shown)
including the lens central axis 150 and originating within the lens
perimeter. The washing system includes at least a first nozzle
assembly 110 which is configured to be supported and aimed toward
external lens 122 by the aiming fixture defined by housing 111, and
the first nozzle assembly includes a barbed fitting for fluid inlet
142 which is in fluid communication with a first laterally offset
washing nozzle 132 which projects from the aiming fixture's distal
side. The first nozzle assembly 110 is configured and aimed to
spray washing fluid toward the external lens surface and across the
field of view, spraying at a first selected spray aiming angle
(e.g., between 1.degree. and 20.degree.) relative to the plane of
the lens external surface. The first nozzle assembly is oriented to
spray from a selected side, meaning that it is aimed to spray along
a first selected spray azimuth angle in relation to a selected
fixed reference point or datum on the lens perimeter.
[0077] Optionally, the first laterally offset washing nozzle 130 is
configured as a non-oscillating shear nozzle configured to generate
a substantially flat fan spray having a selected spray fan angle
(e.g., 45.degree. or another angled selected in the range of
15.degree. to 120.degree.). Alternatively, first laterally offset
washing nozzle 130 may be configured as a non-oscillating bug-eye
nozzle configured to generate at least one substantially solid
fluid jet (i.e., a substantially solid fluid stream having no fan
angle).
[0078] Preferably, the first laterally offset washing nozzle 130 is
configured to aim the laterally offset washing nozzle from a first
selected lateral offset distance from the center of the objective
lens' external surface (e.g., the first selected lateral offset
distance is preferably within the range bounded by 10 mm and 30 mm)
for a spray having a fan angle in the range of 15.degree. to
120.degree..
[0079] Turning now to FIGS. 3A-3D and FIG. 4, FIGS. 3A-3D are
photographs illustrating a configuration of and displayed "before
and after" performance of an imaging system with a sealed camera
housing 212 and an aimed nozzle assembly 210 with laterally offset
nozzle 230, in accordance with the present invention. FIG. 4 is a
schematic diagram illustrating a fluidic spray 236 from camera
housing 212 nozzle assembly 210 with laterally offset nozzle 230,
and FIGS. 5A and 5B are schematic diagrams illustrating a
perspective view and a side view of a fluid sheet 236 sprayed by an
aimed nozzle 230 configured for the method for cleaning the imaging
system's exterior objective lens surface 222, in accordance with
the present invention.
[0080] Returning to FIG. 3A, a soiled or dirty objective lens
surface 222 has been coated with a representative distribution of
"SAE mud", which serves as a standard exemplar of a coating of road
grime or debris 223. FIG. 3B is a photograph of the image generated
by camera 212 while coated with debris 223 and the debris 223 is
clearly obstructing the displayed view 209A as displayed to the
user or driver. FIGS. 3C and 3D are photographs illustrating the
washing or debris removal effect of the system of the present
Invention, and illustrate (in FIG. 3C) that debris 223 has been
entirely removed from the distal surface of camera housing 212 and
lens surface 222 by spray 236. In addition, the user operating the
washer system 210 has been able to actuate the system to spray from
aimed nozzle 230 while viewing displayed view 209A and so knows
when to stop the washing, since debris 223 has been entirely
removed from the distal surface of camera housing 212 and is seen
to no longer obstruct lens surface 222.
[0081] As illustrated in FIGS. 3A-5B, external lens washing system
210 includes a substantially rigid aiming fixture having a distal
side and a proximal side and being configured to support and
constrain an external lens 222 exposed toward the distal side; the
external lens has an external lens surface with a lens perimeter
and a lens central axis 250 projecting distally from the lens
surface 222, wherein a lens field of view is defined as a distally
projecting solid angle (e.g., a truncated pyramid, encompassing the
view in display 209A) including the lens central axis 250 and
originating within the lens perimeter. Washing system 210 includes
at least a first nozzle assembly configured to be supported and
aimed toward the external lens 222 by the aiming fixture, and the
first nozzle assembly includes a fluid inlet (not shown) in fluid
communication with a first laterally offset washing nozzle 230
which projects from the aiming fixture's distal side. The nozzle
230 is configured and aimed to spray washing fluid in a
substantially planar sheet 236 having a selected thickness 255
toward the external lens surface 222 and across the field of view,
spraying at a first selected spray aiming angle (i.e., preferably
spraying in a plane inclined proximally at an angle) of about
1.degree.. The selected aiming angle can be in a range between
1.degree. and 20.degree. (as seen in FIGS. 4 and 5B) relative to a
plane tangent to the lens external surface 222. Nozzle 230 is
oriented to spray from a selected side, meaning that it is aimed to
spray along a first selected spray azimuth angle in relation to a
selected fixed reference point or datum 251 on the lens
perimeter.
[0082] Preferably, lens washing nozzle 230 includes a first fluidic
oscillator interaction chamber configured to operate on a
selectively actuated flow of pressurized washing fluid flowing
through the first oscillator's chamber to generate a first exhaust
flow of fluid droplets 236, and the first nozzle assembly's fluid
inlet receives pressurized washer fluid and is in fluid
communication with the first interaction chamber which passes the
pressurized washer fluid distally to the first laterally offset
outlet nozzle 230 which is configured to exhaust the washer fluid
from the first interaction chamber and generate a first oscillating
spray of fluid droplets 236 aimed toward the external lens surface
222 and across the field of view. Preferably that fluidic
oscillator is configured as a stepped mushroom fluidic oscillator
(as illustrated in FIGS. 12A and 12B). The preferred spray flow
rate is approximately 200 ml/min per nozzle at 18 psi, and the
spray thickness 255 (i.e., which is seen as thickness in the spray
plane transverse to the spray's fan angle plane, as shown in FIG.
5B) is preferably approximately 2 degrees. The oscillating action
and large drops generated by the fluidic oscillator aimed by nozzle
230 in this manner were discovered to wet lens surface 222 very
rapidly and provided a kinetic impact effect which was found to
impact, flood and drive debris 223 as part of a flowing effluent
238 laterally off lens surface 222.
[0083] Optionally, laterally offset washing nozzle 230 is
configured as a non-oscillating shear nozzle configured to generate
a substantially flat fan spray having a selected spray fan angle
(e.g., 45.degree. or another angled selected in the range of
15.degree. to 120.degree.). Alternatively, first laterally offset
washing nozzle may be configured as a non-oscillating bug-eye
nozzle configured to generate at least one substantially solid
fluid jet (i.e., a substantially solid fluid stream having no fan
angle).
[0084] Preferably, the first laterally offset washing nozzle 230 is
configured to aim the spray 236 from a first selected lateral
offset distance (from the nozzle's throat or outlet to the center
of objective lens' external surface 222) of about 15 mm. The
selected lateral offset distance is preferably within the range
bounded by 10 mm and 30 mm, in order to keep the entire package as
compact as possible.
[0085] Some external camera systems include convex or dome-shaped
lens surfaces, which can be more difficult to clean. As shown in
FIGS. 6A and 6B, the system of the present invention can be
configured with plural nozzle assemblies to effectively clean
different image sensor housing configurations and different
external lens surface shapes. Optionally, as shown in FIGS. 6A and
6B, an external lens washing system 210 of FIG. 3A-5B can Include a
second nozzle 232 configured to be supported and aimed by the
aiming fixture, where the second nozzle 232 is configured and aimed
direct a second spray 237 along a second selected spray azimuth
angle being radially spaced at a selected inter-spray angle (e.g.,
180.degree.) from the first nozzle assembly's spray azimuth angle,
aiming second spray 237 to oppose first spray 236.
[0086] For the external lens washing system illustrated in FIGS. 6A
and 6B, the second nozzle assembly 232 preferably has a second
fluidic oscillator interaction chamber configured to operate on a
selectively actuated flow of pressurized washing fluid flowing
through the second oscillator's chamber to generate the second
exhaust flow of fluid droplets 237. Second nozzle assembly 232
receives pressurized washer fluid and is in fluid communication
with the second interaction chamber which passes the pressurized
washer fluid distally to the second laterally offset nozzle's
outlet or throat which is configured to exhaust the washer fluid
from the second interaction chamber and generate the second
oscillating spray of fluid droplets 237 which is also aimed toward
the external lens surface 222 and across the field of view. The
second fluidic oscillator is also preferably configured as a
stepped mushroom fluidic oscillator.
[0087] Impinging fluid jets 236, 237 are aimed to create a specific
hydraulic effect and cooperate to distribute fluid across the lens
surface in very little time. As the colliding and impinging fluid
jets 236, 237 impact debris 223 (not shown) and the lens surface
the provided a kinetic impact effect which was found to dislodge,
dissolve and drive debris as a turbulent flowing effluent 238
laterally off lens surface 222. The preferred spray flow rate for
each nozzle 230, 232 is approximately 200 ml/min per nozzle at 18
psi, and the spray thickness 255 (i.e., which is seen as thickness
in the spray plane transverse to the spray's fan angle plane, as
shown in FIGS. 5B and 6B) is preferably approximately 2
degrees.
[0088] Optionally, second laterally offset washing nozzle 232 is
configured as a non-oscillating shear nozzle configured to generate
a substantially flat fan spray having a selected spray fan angle
(e.g., 45.degree. or another angled selected in the range of
15.degree. to 120.degree.). Alternatively, second laterally offset
washing nozzle 232 may be configured as a non-oscillating bug-eye
nozzle configured to generate at least one substantially solid
fluid jet (i.e., a substantially solid fluid stream having no fan
angle).
[0089] Preferably, the second laterally offset washing nozzle 232
is configured to aim the spray 237 from a first selected lateral
offset distance (from the nozzle's throat or outlet to the center
of objective lens' external surface 222) of about 15 mm. The
selected lateral offset distance is preferably within the range
bounded by 10 mm and 30 mm, in order to keep the entire washing
system's package as compact as possible.
[0090] Turning now to system diagrams 7 and 8, The lens washing
system of the present invention is readily integrated into standard
equipment already specified for inclusion in many automobiles and
other vehicles (e.g., 8). As best seen in FIG. 7, vehicles (e.g.,
8) configured with an existing windshield washing system ("front
wash") or rear window washing system ("rear wash") require use of a
washing fluid reservoir and pumping system to provide a supply of
pressurized washing fluid. Washer tank or reservoir 290 typically
includes an internal pump 292 which is activated to draw washing
fluid from the reservoir 290 and supply pressurized fluid to a
conduit network 294 (e.g., comprising lumens, tubes or hoses) which
supply the windshield washing nozzles 296 and rear window washing
nozzle(s) 298. In accordance with one embodiment of the present
invention, the system of the present invention (e.g., 110 or 210)
actuates lens washing in response to driver control input or
automatically. In automatic operation, lens washing is initiated or
triggered in response to the driver's use of the windshield washing
system or "front wash" (e.g., where lens washing happens every time
the windshield is sprayed with front wash nozzle 296 or
alternatively, lens wash may be selectively actuated periodically,
with one momentary lens wash cycle for every 3-5 front wash
events). Similarly, rear window or liftgate/backlight cleaning can
be linked to the lens washing for a back-up camera system wherein
backup camera lens washing happens every time the rear window is
sprayed with rear wash nozzle 298 or alternatively, a backup camera
lens wash may be selectively actuated periodically, with one
momentary lens wash cycle for every 3-5 rear wash events.
[0091] Alternatively, camera lens washing may be user-controlled
using an interior display (e.g., 9a) wherein remotely controllable
system 310 includes at least one nozzle assembly 210 and configured
to clean the external image sensor's objective lens surface and
washing off accumulated image distorting debris 223 uses the
display mounted within the vehicle's interior 9A connected to the
vehicle's data communication network to receive image signals for
display to the driver. The external image sensor is configured to
generate an external image display the sensor's external objective
lens surface 222 is aimed toward the vehicle's exterior (e.g.,
rear, front or to the sides of vehicle 8) and the sensor or camera
has a selected field of view. The image sensor being substantially
exposed to the ambient environment and accumulated image distorting
debris when the vehicle is in use. The image sensor lens washing
system is configured with laterally offset washing nozzle 230 to
selectively spray washing fluid onto the image sensor's objective
lens surface at a narrow, glancing angle, the spray being aimed
across the field of view along an aiming angle which is aimed at a
selected aiming angle that within the range bounded by 1.degree.
and 20.degree. in relation to the external objective lens surface,
and the spray being actuated in response to a momentary wash
control signal of a few seconds duration. The washing system
actuation switch mounted within the Interior of vehicle 8 and is
configured to selectively and momentarily generate the wash control
signal when actuation of the lens washing system 210 is desired by
the driver, while viewing the display 9A.
[0092] Turning now to FIG. 8, The lens washing system of the
present invention is readily integrated into standard equipment
already specified for Inclusion in many automobiles and other
vehicles (e.g., 8). A vehicles (e.g., 8) configured with a front
wash system also requires use of a washing fluid reservoir and
pumping system to provide a supply of pressurized washing fluid.
Washer tank or reservoir 290 has an internal dual outlet pump 293
which is activated to draw washing fluid from the reservoir 290 and
supply pressurized fluid to a conduit network 294 (e.g., comprising
lumens, tubes or hoses) which supply the windshield washing nozzles
296 and via a rear or secondary outlet conduit, supplies camera
washing system 210. Pressurized fluid transmission to camera system
210 may be controlled either by selective actuation of pump 293 or
by control of one or more valves (not shown) placed to either allow
or stop washer fluid flow to lens washing assembly 210.
[0093] In accordance with another embodiment of the system of the
present invention, lens washing system 311 is actuated in response
to driver control input or automatically. In automatic operation,
lens washing is Initiated or triggered in response to the driver's
use of the windshield washing system or "front wash" (e.g., where
lens washing happens every time the windshield is sprayed with
front wash nozzle 296 or alternatively, lens wash may be
selectively actuated periodically, with one momentary lens wash
cycle for every 3-5 front wash events).
[0094] Alternatively, for system 311, as illustrated in FIG. 8,
camera lens washing may be user-controlled using an interior
display (e.g., 9a) wherein remotely controllable system 311
includes at least one nozzle assembly 210 and configured to clean
the external image sensor's objective lens surface and washing off
accumulated image distorting debris 223 uses the display mounted
within the vehicle's interior 9A connected to the vehicle's data
communication network to receive image signals for display to the
driver. The external image sensor is configured to generate an
external image display the sensor's external objective lens surface
222 is aimed toward the vehicle's exterior (e.g., rear, front or to
the sides of vehicle 8) and the sensor or camera has a selected
field of view. The image sensor being substantially exposed to the
ambient environment and accumulated image distorting debris when
the vehicle is in use. The image sensor lens washing system is
configured with laterally offset washing nozzle 230 to selectively
spray washing fluid onto the Image sensor's objective lens surface
at a narrow, glancing angle, the spray being aimed across the field
of view along an aiming angle which is aimed at a selected aiming
angle that within the range bounded by 1.degree. and 20.degree. in
relation to the external objective lens surface, and the spray
being actuated in response to a momentary wash control signal of a
few seconds duration. The washing system actuation switch mounted
within the interior of vehicle 8 and is configured to selectively
and momentarily generate the wash control signal when actuation of
the lens washing system 210 is desired by the driver, while viewing
the display 9A.
[0095] Turning now to FIGS. 9-11, a bracket indexed external lens
washing system 310 is illustrated. As illustrated in FIG. 9,
external lens washing system 310 includes a substantially rigid
aiming bracket or fixture 311 having a distal side 311D and a
proximal side 311P (best seen in the cross section view of FIG.
10). Fixture or bracket 311 is a rigid durable support fabricated
and configured to support camera module 312 and thus orients and
constrains the camera's external lens which is exposed toward the
distal side of assembly 310. The camera's lens has an external lens
surface 322 with a lens perimeter and a lens central axis 350
projecting distally from the lens surface 322, and the lens field
of view is defined as a distally projecting solid angle (e.g., a
truncated cone or pyramid, generating an image signal having, for
example, the view in display 209A). The Field of View ("FOV")
typically has an angular width of 90.degree. to 170.degree.. The
camera or image sensor 312 has a lens central axis 350 centered
within the lens perimeter and the lens FOV is typically symmetrical
about lens central axis 350.
[0096] Washing system 310 includes at least a first nozzle assembly
330 configured to be supported and aimed toward the external lens
322 by the aiming fixture 311, and the first nozzle assembly
includes a fluid inlet 342 in fluid communication with first
laterally offset washing nozzle 330 which projects above or
distally from the aiming fixture's distal side 311D. Laterally
offset nozzle 330 is configured and aimed to spray washing fluid in
a substantially planar sheet 336 having a selected thickness (e.g.,
255) toward external lens surface 322 and across the field of view,
spraying at a first selected spray aiming angle (i.e., preferably
spraying in a plane inclined proximally at an angle) of about
1.degree.. The selected aiming angle can be in a range between
1.degree. and 20.degree. (as best seen in FIG. 10) relative to a
plane tangent to the lens external surface 322. Nozzle 330 is
oriented to spray from a selected side, meaning that it is aimed to
spray along a first selected spray azimuth angle in relation to a
selected fixed reference point or datum 351 on the lens
perimeter.
[0097] Preferably, lens washing nozzle 330 includes a first fluidic
oscillator interaction chamber 331 configured to operate on a
selectively actuated flow of pressurized washing fluid flowing
through the first oscillator's chamber 331 to generate a first
exhaust flow of fluid droplets 336, and the first nozzle assembly's
fluid inlet 342 receives pressurized washer fluid (e.g., from
reservoir 290) and is in fluid communication via fluid path 340
which passes the pressurized washer fluid distally to the first
laterally offset outlet nozzle 330 which is configured to exhaust
the washer fluid from the first interaction chamber 331 and
generate a first oscillating spray of fluid droplets 336 aimed
toward the external lens surface 322 and across the field of view.
Preferably the fluidic oscillator including interaction chamber 331
is configured as a stepped mushroom fluidic oscillator (as
illustrated in FIGS. 12A and 12B). The preferred flow rate in
oscillating spray 336 is preferably approximately 200 ml/min per
nozzle at 18 psi, and the spray thickness (i.e., which is seen as
thickness in the spray plane transverse to the spray's fan angle
plane, as shown in FIGS. 10 and 5B) is preferably approximately 2
degrees. The oscillating action and large drops generated by the
fluidic oscillator aimed by nozzle 330 in this manner was
discovered to wet lens surface 322 very rapidly and provided a
kinetic impact effect which was found to impact, dissolve and drive
debris (not shown, but like debris 223) as part of a flowing
effluent laterally off lens surface 222.
[0098] Optionally, laterally offset washing nozzle 330 may be
configured as a non-oscillating shear nozzle configured to generate
a substantially flat fan spray having a selected spray fan angle
(e.g., 45.degree. or another angled selected in the range of
15.degree. to 120.degree.). Alternatively, first laterally offset
washing nozzle 33 may be configured as a non-oscillating bug-eye
nozzle configured to generate at least one substantially solid
fluid jet (i.e., a substantially solid fluid stream having no fan
angle).
[0099] Preferably, the laterally offset washing nozzle 330 is
configured to aim the spray 336 from a first selected lateral
offset distance (from the nozzle's throat or outlet to the center
of objective lens' external surface 222, see FIG. 11) of about 15
mm. The selected lateral offset distance is preferably within the
range bounded by 10 mm and 30 mm, in order to keep the entire
package as compact as possible.
[0100] In the embodiment illustrated in FIGS. 9-11 has camera 312
with lens 322, a nozzle 330 mounted distally and aiming spray 336
nearly parallel to the lens 322 and associated bracketing (i.e.,
fixture 311) that is necessary to hold nozzle 330 in a fixed
location relative to the lens both (in lateral offset and azimuth)
from the center line of the lens and distally or above the lens.
There are several variables to consider when designing for this
camera cleaning system and package, including: mounting methods,
packaging space, Field of View (FOV) considerations and Adverse
System Effect Mitigation. Taking each in turn:
[0101] Mounting Methods
[0102] One preferred mounting or attachment method for the nozzle
330 with the camera 312 is on the camera module housing or body,
directly. This mounting location assures that no matter where the
camera moves, fluid sprayed from the nozzle is always aimed at the
right location toward the center of the lens surface. A nozzle
mounted separately from the camera could be subject to extra
tolerance stackups and become mis-aimed. It is of course,
understood that there will be some camera designs that do not allow
for direct attachment and will require separate mounting schemes.
The basics of good nozzle placement discussed above are the same
regardless of attachment method.
[0103] Packaging Space
[0104] In general, the location of cameras (e.g., 312) in vehicles
(e.g., 8) is limited to certain specific regions, due to packaging
and line-of-sight objectives. Unfortunately for camera wash nozzle
packaging, prime vehicle panel exterior locations also tend to be
good for other components like; liftgate handles or lighting
components. As a result, these vehicle panel exterior locations
have very tight packaging constraints, driving the need for very
small nozzles and tight camera-to-nozzle envelopes.
[0105] Field of View Considerations
[0106] It should be understood that many existing cameras have
Field of View Angles from 120 to 170 degrees (e.g., as indicated by
radial lines in FIGS. 9-11). A major constraint to system
functionality is to have nothing Intrude into the displayed field
of view of the camera, (e.g., 209A) so that the user is not
distracted by the appearance of the lens washing nozzle 330. Thus
the nozzle (e.g., 230 or 330) should be laterally positioned such
that it is not in the camera FOV. In the illustrated embodiments of
the present invention, the nozzle (e.g., 230 or 330) is oriented
and aimed from a fixed nearly parallel-to-lens location, to be away
from and behind the FOV of the camera. As the camera FOV's
approaches and exceeds 180 degrees this will become impossible.
However, it will be noted that with these large angles other
components in the vehicle will become visible to the camera. It
will then be necessary to place the nozzle (e.g., 230 or 330) such
that it aligned with the vehicle's other features and is thereby
not silhouetted beyond (and so is "hidden" in the clutter of) the
vehicle's exterior surface features, minimizing intrusion into
"clear" view of the camera. In the embodiment of FIGS. 9-11, nozzle
330 creates a fluid distribution such that the entirety, or as much
as possible, of the lens is covered by fluid and Impacts the lens
at -1 degrees to -20 degrees or so before the nozzle head becomes
visible to the camera, ("aim angle"). Another significant advantage
to nearly parallel impact of the spray 336 to the lens 322 is that
the fluid is fully engaged in pushing the debris off or laterally
across the lens, and not in obliquely impact or bouncing off the
lens as would be experienced in higher aim angles, with a more
direct impingement. As the aim angle increases, the nozzle must be
moved distally further and up into the FOV, and farther from the
camera, making cosmetically attractive packaging difficult.
Therefore, the nozzle should be kept within 10 degrees (aim angle
down to the lens) to keep cosmetic packaging reasonable.
[0107] In addition to aim angle considerations, the nozzle distance
from the center of the lens (as illustrated in FIG. 11) is
important. The closer nozzle 330 is to the center of the lens 322,
the wider the fluid distribution (and spray fan angle) must be to
cover the entirety of the lens. Excessive closeness to the lens
center is objectionable for a number of reasons. Firstly, the
nozzle is simply too close to the camera body and may crash with it
physically. Secondly, the wider the distribution angle (or spray
fan angle) needs to be to get good coverage. Wider spray fan angles
spread a relatively small fluid flow rate over a larger lens
cleaning area, which could result in the need for a different
distribution geometry or higher flow rates. Applicants have found
that with one effective distribution geometry, the lateral offset
distance is preferably between 18 mm and 28 mm. This lateral offset
is approximate, as aim angle and nozzle distal height variations
tend to complicate the geometry.
[0108] Adverse System Effect Mitigation
[0109] Addition of cleaning systems (e.g., 310) to vehicle systems
can be accomplished in a number of ways. They can be tied into
existing systems, like rear glass cleaning in an SUV, whereby the
camera is cleaned whenever the rear glass is cleaned and
vice-a-versa. Systems can also be designed such that cleaning in
on-demand, and requires the addition of a pump (e.g. 292) and
controller or control system (e.g., 98) programmed to perform the
method steps described above. However, it is highly preferable to
keep the same number and size of the washer fluid reservoir(s)
(e.g., 290). It is highly unlikely that a second reservoir or fluid
bottle would be added to vehicle 8, thus the camera cleaning nozzle
system (e.g., 310) is likely to be seen as a parasitic system with
regard to overall vehicle performance. Since vehicle packaging
generally does not allow for larger washer reservoirs, any camera
cleaning system must consume as little fluid as possible to have
the least impact on the overall vehicle performance.
[0110] Since minimizing the overall effect of the addition of the
lens washer system (e.g., 310) to the systems of vehicle 8 is
desired, a small flow rate is preferred for the nozzle (e.g., 330).
One embodiment used a fluidic nozzle with a target flow rate of
200+/-40 mL/min @ 18 PSI and this was shown to be very effective in
cleaning the lens 322 with the aforementioned packaging guidelines.
With these flow and packaging considerations in mind, the stepped
mushroom circuit of FIGS. 12A and 12B was chosen for the preferred
fluid delivery geometry embodiment of FIGS. 9-11. This fluidic
circuit (e.g., with stepped mushroom chip 501) is capable of
performing well in cold weather conditions with 0.06 mm step and
allows for very small packaging at 5 mm.times.5 mm for a 200 mL/min
flow rate and 50.degree. spray fan angle for spray 336. Most
importantly, this design can maintain a minimum 0.014'' power
nozzle dimension which is required for good clog resistant
performance. Power nozzles smaller than this risk clogging in
automotive situations. The fluidic circuit has also been provided
with internal filters (e.g., posts 522).
Additionally, this circuit design allows for a small interaction
region 331, approximately 3.3 mm.times.2.5 mm, helping to support
fan angles as high as 50 degrees and still staying within the
target packaging space.
[0111] The lens washer nozzle assemblies (e.g., 110, 210, 310, 610
or 710) preferably a include fluidic oscillators as part of a
nozzle assembly and preferably a stepped mushroom fluidic
oscillator as described in commonly owned U.S. Pat. No. 7,267,290,
the entirety of which is incorporated herein by reference.
Referring again to FIGS. 12A and 12B, the lens washer nozzle
fluidic oscillator is optionally configured as a removable fluidic
chip 501 having an oscillating chamber defined between the fluid
impermeable surfaces of chip 501 and the nozzle assembly's
chip-receiving interior surfaces (as seen in section in FIG. 10).
Referring again to FIGS. 10, 12A and 12B the fluidic oscillator
with interaction chamber 331 as configured in nozzle assembly 310
is suitable for use at colder temperatures for an exhaust flow in
the form of oscillating spray of fluid droplets 336 and has a pair
of power nozzles 514 configured to accelerate the movement of the
pressurized fluid, a fluid pathway that connects and allows for the
flow of pressurized fluid between its inlet 512 and the power
nozzles 514, an interaction chamber 518 which is attached to the
nozzles and receives the flow from the nozzles, a fluid spray
outlet 520 from which the spray exhausts from the interaction
chamber, and a flow instability generating structural feature for
increasing the instability of the fluid's flow from the power
nozzles, with this structural feature being situated in a location
chosen from the group consisting of a location within the fluid
pathway or proximate the power nozzles. The flow instability
generating feature preferably comprises a protrusion that extends
inward from each sidewall 506 of the fluid pathway so as to cause a
flow separation region downstream of the protrusions, but may
comprise a step 524A in the height elevation of the floor of the
power nozzles 514 with respect to that of the interaction chamber,
as best seen in FIG. 12B.
[0112] Turning now to FIGS. 13A-C, another embodiment for the
external lens washing system and nozzle assembly 610 includes a
substantially rigid bezel or aiming fixture 611 having a distal
side 611D and a proximal side 611P. Bezel or fixture 611 is
configured to support an image sensor or camera 612 and constrain
the camera's external lens exposed toward the distal side; the
external lens has an external lens surface 622 with a lens
perimeter and a lens central axis 650 projecting distally from the
lens surface 222, wherein a lens field of view is defined as a
distally projecting solid angle (e.g., a truncated cone or pyramid,
encompassing the view in display 209A) including the lens central
axis 650 and originating within the lens perimeter. Washing system
610 includes at least a first nozzle assembly configured to be
supported and aimed toward the external lens 622 by the bezel or
aiming fixture 611, and the first nozzle assembly includes a fluid
inlet 642 in fluid communication with a first laterally offset
washing nozzle 630 which distally projects from the aiming
fixture's distal side 611D. The nozzle 630 is configured and aimed
to spray washing fluid in a substantially planar sheet 636 having a
selected thickness toward the external lens surface 622 and across
the field of view, spraying at a first selected spray aiming angle
(i.e., preferably spraying in a plane inclined proximally at an
angle) of about 1.degree.. The selected aiming angle can be in a
range between 1.degree. and 20.degree. (as seen in FIGS. 13B, 13C
and 5B) relative to a plane tangent to the lens external surface
622. Nozzle 630 is oriented to spray from a selected side, meaning
that it is aimed to spray along a first selected spray azimuth
angle in relation to a selected fixed reference point or datum 651
on the lens perimeter.
[0113] Preferably, lens washing nozzle 630 includes a first fluidic
oscillator interaction chamber 631 configured to operate on a
selectively actuated flow of pressurized washing fluid flowing
through the first oscillator's chamber to generate a first exhaust
flow of fluid droplets 636, and the first nozzle assembly's fluid
inlet 642 receives pressurized washer fluid and is in fluid
communication with the first interaction chamber 631 which passes
the pressurized washer fluid distally to the first laterally offset
outlet nozzle 630 which is configured to exhaust the washer fluid
from the first interaction chamber and generate a first oscillating
spray of fluid droplets 636 aimed toward the external lens surface
622 and across the field of view. Preferably, as noted above, that
fluidic oscillator is configured as a stepped mushroom fluidic
oscillator (as illustrated in FIGS. 12A and 12B). The preferred
spray flow rate is approximately 200 ml/min per nozzle at 18 psi,
and the spray thickness (i.e., which is seen as thickness in the
spray plane transverse to the spray's fan angle plane, as shown in
FIG. 5B) is preferably approximately 2 degrees. The oscillating
action and large drops generated by the fluidic oscillator aimed by
nozzle 630 in this manner were discovered to wet lens surface 622
very rapidly and provided a kinetic impact effect which was found
to impact, dissolve and drive debris (e.g., like 223, not shown) as
part of a flowing effluent laterally off lens surface 622.
[0114] Optionally, laterally offset washing nozzle 630 is
configured as a non-oscillating shear nozzle configured to generate
a substantially flat fan spray having a selected spray fan angle
(e.g., 45.degree. or another angled selected in the range of
15.degree. to 120.degree.). Alternatively, first laterally offset
washing nozzle may be configured as a non-oscillating bug-eye
nozzle configured to generate at least one substantially solid
fluid jet (i.e., a substantially solid fluid stream having no fan
angle).
[0115] Preferably, the first laterally offset washing nozzle 630 is
configured to aim the spray 636 from a first selected lateral
offset distance (from the nozzle's throat or outlet to the center
of objective lens' external surface 622) of about 15 mm. The
selected lateral offset distance is preferably within the range
bounded by 10 mm and 30 mm, in order to keep the entire package as
compact as possible.
[0116] The camera lens washing assembly 610 illustrated in FIGS.
13A-13C is preferably is configured as an integrated automotive
camera module and nozzle assembly, with 612 camera module and the
aimed nozzle assembly integrally packaged as a one-piece unitary
module configured for assembly into a vehicle 8. Substantially
fluid impermeable camera module 612 is affixed within bezel or
housing 611 and has an interior configured to enclose and aim an
imaging sensor having an objective lens and a pixelated image
sensor array (e.g., like 18), where bezel or housing 611 is
configured to support and aim the camera module 612. Camera module
612 comprises a self-contained and sealed module enclosing the
image sensor array (e.g., like 18) and associated image signal
processing components (e.g., as illustrated in FIG. 1D), and is
substantially sealed to limit or substantially preclude water
intrusion into the camera module's interior volume. Camera module
612 and integral housing 611 are configured to be positioned at or
affixed upon vehicle 8 as a camera lens and lens washer unit 610.
Camera module 612 also includes an electrical connector 670
suitable for electrically conductive connection to a vehicle
electrical connector when the camera module housing is positioned
at the vehicle 8. The camera module's electrical connector extends
to be accessible at a proximal end 672 for connecting to the
vehicle electrical connector (or vehicle controller 9B) when the
camera module is positioned at the vehicle 8 and camera module 612
is responsive to vehicle controller 9B to process video images
captured by the imaging sensor.
[0117] In accordance with the present invention, an integrated
automotive system, fluidic circuit nozzle assembly (e.g., 210, 310,
610 or 710) are useful in the practicing method for aiming an
oscillating spray to clean an exterior objective lens surface and
allows the driver to determine when to clean a soiled external-view
camera's objective lens, so the driver can ensure that the lens is
adequately cleaned before moving.
[0118] In the lens cleaning system of the present invention (e.g.,
110, 210, 310, 610 or 710), low flow rate fluidic circuit nozzles
may be configured to effect bottle cleanings savings, conservation
of fluid, and conservation of pressure. Conservation of pressure is
especially important when the camera lens cleaning system is
integrated into an existing front wash system, where the camera
lens washing system must function without detrimentally affecting
front glass cleaning, especially under dynamic driving conditions,
where the front glass cleaning system's performance is highly
sensitive to fluid pressure. The system and method of the present
invention is not limited to use with low flow rate nozzles
exclusively. Applicants have prototyped a relatively high flow rate
nozzle assembly on an exemplary system and it works well, although
the camera's image is somewhat compromised when washing. It appears
that the low flow rate is best accomplished thru a selected fluidic
circuit geometry which allows washing fluid, since droplet size
should remain larger when compared to a shear nozzle's
non-oscillating spray.
[0119] The optimum lens washing nozzle location of the present
invention presents a very nicely distributed oscillating spray
pattern with the following benefits:
[0120] Allows for nearly flush mounting to the camera lens, means
the package does not get longer and interfere, or interfere as
much, with camera viewing angles as a directed impact nozzle would;
and
[0121] can be packaged in really close to keep the overall width of
the package from growing larger; e.g., a dome-shaped or convex
("bug-eye") lens would likely need to have the nozzle spray
originate above the lens, angled down, and pushed away from the
center line to avoid sight lines, although this would result in a
wider and longer package.
[0122] The applicants have found that directly spraying nearly
parallel to the objective lens assembly's external surface results
in less washing fluid (e.g., water) remaining on the lens after
conclusion of spraying, preventing water droplets from forming on
the lens and obstructing the view, whereas, in prototype
development experiments, a more nearly on-lens axis or direct
impingement spray method is likely to leave view-obstructing
droplets behind.
Telescoping Pop-Up Lens Washers for Wide-Angle Image Sensor
Applications:
[0123] Turning now to FIGS. 14A-17, a pop-up embodiment for the
external lens washing system and nozzle assembly 710 includes a
telescoping, extendable aiming fixture 711 having a cosmetic cover
on distal end 711D and a proximal side 711P. Extendable aiming
fixture 711 is configured to aim a spray at the exterior surface of
image sensor or camera 712 when the camera's external lens or
sensor surface is exposed toward the distal side; the external lens
or sensor has an external surface 722 with a lens perimeter and a
lens central axis 750 projecting distally from the lens surface
222, wherein a wide-angle lens field of view is defined as a
distally projecting solid angle (e.g., a truncated cone or pyramid,
encompassing the view in display 209A) including the lens central
axis 750 and originating within the lens perimeter. Pop-up lens
washing system 710 includes at least a first nozzle assembly
configured to be supported and aimed toward the external lens 722
by the extendable aiming fixture 711, and the first nozzle assembly
includes a fluid inlet 742 in fluid communication with a first
laterally offset washing nozzle 730 which distally projects from
the aiming fixture's distal side. When in the extended or
telescoped state (see FIGS. 14B, 16B and 17), the nozzle 730 is
configured and aimed to spray washing fluid in a substantially
planar sheet 736 having a selected thickness toward the external
lens surface 722 and across the field of view, spraying at a first
selected spray aiming angle (i.e., preferably spraying in a plane
inclined proximally at an angle) of about 1.degree.. The selected
aiming angle can be in a range between 1.degree. and 20.degree. (as
seen in FIGS. 14B, and 17) relative to a plane tangent to the lens
external surface 722. Nozzle 730 is oriented to spray from a
selected side, meaning that it is aimed to spray along a first
selected spray azimuth angle in relation to a selected fixed
reference point or datum 751 on the lens perimeter.
[0124] Preferably, lens washing nozzle 730 includes a first fluidic
oscillator insert 731 with an interaction chamber configured to
operate on a selectively actuated flow of pressurized washing fluid
flowing through the first oscillator's chamber to generate a first
exhaust flow of fluid droplets 736, and the first nozzle assembly's
fluid inlet 742 receives pressurized washer fluid and is in fluid
communication with the first fluidic insert's interaction chamber
which passes the pressurized washer fluid distally to the first
laterally offset outlet of nozzle 730 which is configured to
exhaust the washer fluid from the first interaction chamber and
generate a first oscillating spray of fluid droplets 736 aimed
toward the external lens surface 722 and across the field of view.
Preferably, as noted above, that fluidic oscillator 731 is
configured as a stepped mushroom fluidic oscillator (as illustrated
in FIGS. 12A and 12B). The preferred spray flow rate is
approximately 200 ml/min per nozzle at 18 psi, and the spray
thickness (i.e., which is seen as thickness in the spray plane
transverse to the spray's fan angle plane, as shown in FIG. 5B) is
preferably approximately 2 degrees. The oscillating action and
large drops generated by the fluidic oscillator aimed by nozzle 730
in this manner were discovered to wet lens surface 722 very rapidly
and provided a kinetic impact effect which was found to impact,
dissolve and drive debris (e.g., like 223, not shown) as part of a
flowing effluent laterally off lens surface 722.
[0125] Optionally, laterally offset pop-up washing nozzle 730 may
be configured as a non-oscillating shear nozzle configured to
generate a substantially flat fan spray having a selected spray fan
angle (e.g., 45.degree. or another angled selected in the range of
15.degree. to 120.degree.). Alternatively, first laterally offset
washing nozzle may be configured as a non-oscillating bug-eye
nozzle configured to generate at least one substantially solid
fluid jet (i.e., a substantially solid fluid stream having no fan
angle).
[0126] Preferably, the first laterally offset pop-up washing nozzle
730 is configured to aim the spray 736 from a first selected
lateral offset distance (from the nozzle's throat or outlet to the
center of objective lens' external surface 722) of about 15-20 mm.
The selected lateral offset distance is preferably within the range
bounded by 5 mm and 30 mm, in order to keep the entire package as
compact as possible. In other embodiments, the lateral offset
distance could be as large as 150 mm, which would permit integrated
system configurations having electronics moving off the lens to
allow for more varied packaging options.
[0127] The pop-up camera lens washing assembly 710 illustrated in
FIGS. 14A-17 is preferably is configured as an integrated
automotive camera module and nozzle assembly, with image sensor or
camera module 712 and the aimed nozzle assembly integrally packaged
as a one-piece unitary module configured for assembly into a
vehicle 8. Substantially fluid impermeable image sensor or camera
module 712 is affixed within a vehicle fascia, bezel or housing and
has an interior configured to enclose and aim an imaging sensor
having an objective lens and a pixelated image sensor array (e.g.,
like 18), where the image sensor's bezel or housing is configured
to support and aim the module 712. Image sensor or camera module
712 comprises a self-contained and sealed module enclosing the
image sensor array (e.g., like 18) and associated image signal
processing components (e.g., as illustrated in FIG. 1D), and is
substantially sealed to limit or substantially preclude water
intrusion into the camera module's interior volume. Camera module
712 is configured to be positioned at or affixed upon vehicle 8 and
includes an electrical connector 770 suitable for electrically
conductive connection to a vehicle electrical connector when the
camera module housing is positioned at the vehicle 8. The camera
module's electrical connector extends to be accessible at a
proximal end 772 for connecting to the vehicle electrical connector
(or vehicle controller 9B) when the camera module is positioned at
the vehicle 8 and camera module 712 is responsive to vehicle
controller 9B to process video images captured by the imaging
sensor.
[0128] Extendable aiming fixture 711 is substantially concealed
behind distal cover 711D when not in use, and the user or an
automatic program can selectively enable the telescoping extension
of the nozzle assembly 730, as illustrated in FIGS. 16A-16C, due to
the sequence of operations which follow activation of a vehicles
washer fluid pump 292. Turning first to FIGS. 15A and 15B, exploded
views of the moving parts of nozzle assembly 730 within extendable
aiming fixture 711 are shown. Nozzle assembly 730 has a resilient
polymer cylindrical outer body 780 terminating distally in a
flanged open end and terminating proximally in a circular end wall
which carries a proximally projecting tubular inlet lumen 742 for
fluid flow into the interior of cylindrical body 780. A cylindrical
inner body 784 is coaxially slideably received within the interior
of outer body 780 and has an inwardly projecting distal annular
flange which bears against and carries a distal O-ring seal 786 and
circular lip seal 788 (as best seen in FIG. 15B). The size of the
inner diameter (I.D.) of o-ring 786 is close to the outer diameter
(O.D.) dimension of the lip seal 788, for reasons explained
below.
[0129] Referring now to FIG. 15A (and FIGS. 16A-16C), a
spring-biased flanged piston 790 is coaxially slideably received
within the interior of cylindrical inner body 784 and carries a
main body spring 792. Spring-biased flanged piston 790 has a distal
end which is also coaxially slideably received within the interior
of cylindrical lumen defined within nozzle housing extension 800,
along with coaxially aligned check valve seal 794, check valve seal
carrier 796 and check valve biasing spring 798. These coaxially
aligned nozzle housing components work together to allow nozzle
housing extension to telescope or extend distally when washer fluid
is pumped into cylindrical inner body 784.
[0130] Referring again to FIGS. 16A-16C, the telescoping extension
of the nozzle assembly 730, as illustrated in FIGS. 16A-16C,
involves a sequence of operations which follow the user's
activation of vehicle washer fluid pump 292, where nozzle assembly
730 has defined states, a first non-operating or quiescent state,
as illustrated in FIG. 16A, has the housing nozzle extension 800
retracted and held in place by biasing spring 792. When the pop-up
lens washer system 710 is activated, the second or washing state is
provided, where nozzle extension 800 is extended and biasing spring
792 is compressed by washer fluid pressure, as illustrated in FIGS.
16B-17. In between the non-operating state and the washing state
are transition states, and the washing operation may be
characterized as a sequence of timed stages, from zero (T0) to four
(T4), as follows:
At T0: Nozzle 730 in a retracted state or position, pressure in
system is ambient or minimal gauge pressure (e.g., less than 5
psi); At T1: Pump 292 activates: From T1.about.T2: Pressure rises
in washer system 710, fluid enters nozzle assembly through inlet
742, filling Fluid Volume A within piston 790. Pumped fluid
pressure operates against lip seal 788 and piston 790, driving
nozzle extension 800 distally and compressing main body spring 792
to create Fluid Volume B within the interior of inner body 784; At
T2: At a second, higher pressure than was necessary to start
hydraulic driving of the nozzle extension 800, the check valve 796
is opened, allowing fluid to flow into Fluid Volume C and out
through the nozzle extension 800 (and the fluidic insert 731),
creating a spray or jet of fluid (e.g., 736); From T2.about.T3:
Nozzle assembly 730 sprays and washes camera or sensor's external
surface 722; At T3: Pump deactivates, pressure in system begins to
drop; and From T3.about.T4: Check valve 796 closes, stopping spray
and maintaining priming of the system 710 for rapid future
activation. Fluid Volume C drains to exterior but Fluid Volume A
and the attached hoses (e.g., 294) remain filled. Nozzle assembly
730 retracts to the first state, original position, driven by the
biasing force of the main body spring 792.
[0131] It will be appreciated by persons having skill in the art
that pop-up lens washing system 710 is well suited for use with
wide angle cameras and sensors (e.g. 712), and provides a
selectively projecting extension 800 when washing and retracts (out
of the camera's or sensor's field of view) when not washing. The
selectively projecting ("pop-up") embodiment of the present
invention as illustrated in FIGS. 14A-17 positions the washer
nozzle on a hydraulic cylinder, and the origin of the wash spray
736 is allowed to be retracted when not in use, reducing or
eliminating field of view issues and allowing the nozzle orifice
(e.g., in Fluidic insert 731 to be shielded from contamination
which might otherwise clog it. Additionally the nozzle may be
masked by a cosmetic cover 711D, cap or other feature which hides
the nozzle and allows it to be placed in a cosmetically important
area without negatively affecting aesthetics. When activated, the
pop-up lens washing nozzle extends such that an acceptable spray
angle of incidence can be achieved to allow efficient and effective
cleaning of the sensor, minimizing the use of washer fluid as well
as minimizing the amount of time that the nozzle is visible to the
sensor or to the end user.
[0132] The selectively projecting ("pop-up") embodiment of the
present invention has a check valve (e.g. 796) operating within the
nozzle body, so the waste of pumped washing fluid is minimized. A
nozzle without a check valve would begin spraying while still in
the retracted position, wasting fluid during the time the nozzle is
extending as well as causing fluid to be sprayed at areas where
fluid may not be desirable. By including the check valve components
794, 796, 798) within the extending portion of the nozzle assembly
730, fluid cannot escape until the device is partially or fully
extended, reducing or eliminating overspray. Retention of the
assembly is controlled by snap tabs or flange members which project
laterally from the distal end of outer body wall 780, so overall
package size is minimized. Other embodiments would use bulkier
retention features, taking up valuable packaging space. The nozzle
housing extension 800 is preferably an integral part of the
hydraulic cylinder assembly which has sliding contact with the
inner body 784, so overall packaging size is reduced and the number
of components is reduced when compared to another embodiment which
has the nozzle housing member carrying the fluidic insert on the
distal end of the hydraulic cylinder mechanism of nozzle assembly
730.
[0133] By placing the o-ring seal 786 above the plane of the lip
seal 788 in the fully extended position, the overall diameter of
the pop-up washing nozzle assembly 730 is minimized compared to an
embodiment which seals lower down, because the size of the inner
diameter (I.D.) of o-ring 786 is close to the outer diameter (O.D.)
dimension of the lip seal 788. If the o-ring were located lower in
the assembly, a larger o-ring and overall package size would be
required to maintain adequate wall thickness of the inner body 784
in the o-ring seal area and keep the same lip seal outer
diameter.
[0134] The extendable washer system 730 is readily adapted for a
wide variety of external surface washing applications with a
variety of fluids, and the extension or projection distance between
the retracted state (FIG. 14A) and the extended or washing state
(FIGS. 14B, 14C) can be 1.5 mm to 150 mm. When washing, aperture
sizes and flow rates for pumped fluid can be configured to work
with operating pressures of 2 psi to 80 psi for flow rates from 10
mL/minute to 1000 mL/minute.
[0135] For any of the washer systems of the present invention
(e.g., 110, 210, 310, 610 or 710), in use, a driver, user or
operator views the image generated by the external camera or image
sensor on an interior video display and decides whether and when to
clean the external camera's objective lens cover's surface to
remove accumulated debris (e.g., accumulated dirt, dust, mud, road
salt or other built-up debris). An interior remote actuation
control input (e.g., button or momentary contact switch) is
provided within the operator's easy reach for convenient use in
cleaning the lens, and the operator actuates the system and causes
the cleansing spray to begin while viewing the image sensor's
output on the video display, stopping actuation of the system when
the operator deems the image sensor's view to be satisfactory.
[0136] Having described preferred embodiments of a new and improved
lens cleaning system and method, it is believed that other
modifications, variations and changes will be suggested to those
skilled in the art in view of the teachings set forth herein. It is
therefore to be understood that all such variations, modifications
and changes are believed to fall within the scope of the appended
claims which define the present invention.
* * * * *