This application is a 371 of PCT/NO2020/050042 filed on Feb. 18, 2020, published on Sep. 24, 2020 under publication number WO 2020/190144 A1, which claims priority benefits from Norwegian Patent Application No. 20190363 filed Mar. 21, 2019, both of which are incorporated herein in their entirety by reference.
The invention relates to a self-cleaning optical housing arrangement for underwater optical systems that utilizes a mechanical cleaning process in order to avoid biofouling. The housing arrangement comprises a first cylindrical shell, a shaft, a motor, a second cylindrical shell element, a cleaning pad, a shaft magnet and a cylinder magnet.
Biofouling is considered a limiting factor when performing ocean monitoring using permanent or long time installations. Optical structures immersed in seawater will under normal conditions be rapidly covered by biofouling, making them useless until cleaned. Systems used for high resolution or high intensity monitoring is particularly sensitive to any optical disturbances, motivating the search for solutions for how to avoid biofouling.
The most common method for avoiding biofouling on optical systems underwater is to add copper material as close to the optical window as possible. This method limits the biofouling, at least for a limited time. Copper is considered potentially toxic, and is therefore prohibited in many situations.
Another more recently developed technique for avoiding biofouling is the use of a nanostructured surface on optical windows. Tear will however after some time remove the nanostructures, and the effect is reduced. The surface will then have to be recoated, a process that for many optical systems is either expensive or impossible to conduct.
It is the aim of the present invention to provide an improved solution for how to reduce the problem with biofouling on underwater optical installations.
The invention provides a self-cleaning optical housing arrangement comprising a first cylindrical shell, comprising a first transparent portion, a shaft, arranged with a shaft axis of rotation along the first cylindrical shell central axis, a motor, connected to the first cylindrical shell and to the shaft, where the motor is configured to rotate the shaft relative to the first cylindrical shell, a second cylindrical shell element, arranged at least in part around the first cylindrical shell and configured to rotate around the first cylindrical shell, the second cylindrical shell element is provided with a second transparent portion configured to be at least in part aligned with the first transparent portion, a cleaning pad, connected to the second cylindrical shell element, and arranged at least in part between the first cylindrical shell and the second cylindrical shell element so that it physically contacts the first cylindrical shell outer surface, a shaft magnet, connected to the shaft, a cylinder magnet, connected to the second cylindrical shell element, where the shaft magnet and the cylinder magnet are arranged in order to magnetically interact such that a rotation of the shaft causes the shaft magnet to exert a force on the cylinder magnet that further causes the second cylindrical shell element to rotate with the shaft, and where, the cleaning pad, upon rotation of the shaft and the second cylindrical shell element, sweeps across, and thereby cleans, at least a part of the outer surface of the first transparent portion.
The optical housing arrangement comprises according to one embodiment of the invention a first cap arranged on a first end of the first cylindrical shell such that it forms a watertight seal with the first cylindrical shell.
According to another embodiment of the invention the motor is connected with the first cylindrical shell via the first cap.
The optical housing arrangement comprises according to yet another embodiment of the invention a second cap, arranged on a second end of the first cylindrical shell such that it forms a watertight seal with the first cylindrical shell, and a bearing connected to the second cap and to the shaft, configured to secure the shaft to the second cap while allowing the shaft to rotate.
The second transparent portion is according to yet another embodiment of the invention an opening.
According to yet another embodiment of the invention the inner volume of the first cylindrical shell is partitioned by one or more essentially non-transparent walls.
The first cylindrical shell comprises according to yet another embodiment of the invention a plurality of cylindrical shell segments connected with each other, where the plurality of cylindrical shell segments are partitioned by one or more essentially non-transparent walls.
The optical housing arrangement further comprises according to yet another embodiment of the invention an optical sensor, configured to detect light from outside the optical housing arrangement, and a light emitting device, configured to illuminate light out of the optical housing arrangement, where the optical sensor and the light emitting device are connected to the shaft and are arranged in the inner volume of the first cylindrical shell.
The optical housing arrangement further comprises according to yet another embodiment of the invention an optical sensor, configured to detect light from outside the optical housing arrangement, and a light emitting device, configured to illuminate light out of the optical housing arrangement, where the optical sensor and the light emitting device are connected to the shaft, are arranged in the inner volume of the first cylindrical shell and are separated by an essentially non-transparent wall.
The shaft comprises according to yet another embodiment of the invention a plurality of parts connected with each other.
The optical housing arrangement further comprises according to yet another embodiment of the invention a plurality of shaft magnets, each connected to the shaft, and a plurality of a cylinder magnets, each connected to the second cylindrical shell element, where the shaft magnets and the cylinder magnets are arranged in order to magnetically interact such that a rotation of the shaft causes the shaft magnets to exert a force on the cylinder magnets that further causes the second cylindrical shell element to rotate with the shaft.
The first cylindrical shell consists according to yet another embodiment of the invention a transparent material.
The cleaning pad has according to yet another embodiment of the invention an elongated shape and where the second cylindrical shell element has an elongated slot with a shape suitable for receiving the cleaning pad.
The optical housing arrangement further comprises according to yet another embodiment of the invention a first and a second cleaning pad magnet arranged in the cleaning pad, and a first and a second mounting magnet, arranged adjacent to the elongated slot, where the first and second mounting magnets are configured to exert a force on the first and a second cleaning pad magnets respectively such that the cleaning pad is pressed against the outer surface of the first cylindrical shell.
According to yet another embodiment of the invention the first and second cleaning pad magnets are respectively arranged in a first and a second distal end of the cleaning pad, where the first and second mounting magnet are respectively arranged adjacent to a first and second distal end of the elongated slot.
Other advantageous features will be apparent from the accompanying claims.
In order to make the invention more readily understandable, the discussion that follows will refer to the accompanying drawings, in which:
In the following, general embodiments as well as particular exemplary embodiments of the invention will be described. References will be made to the accompanying drawings. It shall be noted, however, that the drawings are exemplary embodiments only, and that other features and embodiments may well be within the scope of the invention as claimed.
The present invention provides an optical housing arrangement suitable for use underwater and for housing various optical equipment, e.g. optical sensors, cameras, detectors, light sources, lenses, polarization filters, etc.
The housing arrangement 100 comprises as schematically illustrated in
As illustrated in
The second cylindrical shell element 170 is as illustrated in
Any cylindrical shell or cylindrical shell element may in the context of the present invention be considered as essentially cylindrical. The structure of the optical housing arrangement will tolerate a deviation from a perfect cylindrical shapes as long as the second cylindrical shell element is shaped such that it may rotate at least in part around the first cylindrical shell. The first cylindrical shell and second cylindrical shell element may thus in the context of the present invention be considered as sufficiently cylindrically shaped so as to allow for the second cylindrical shell element to rotate around the first cylindrical shell.
The second cylindrical shell element 170 comprises as illustrated in
A cleaning pad is as illustrated in
At least one shaft magnet 210 and at least one cylinder magnet 220 are according to the invention arranged such that they magnetically interact with each other, either through attractive or repulsive forces. Such interaction may be achieved as visualized in
A rotation of the second cylindrical shell element 170 around the first cylindrical shell 110 causes the cleaning pad to sweep across, and consequently clean the outer surface 200 of the first cylindrical shell 110. The cleaning pad may as illustrated in
The second cylindrical shell element 170 is according to the invention arranged at least in part around the first cylindrical shell and configured to be rotated around the first cylindrical shell. The second cylindrical shell element 170 may be arranged adjoining, adjacent to, or at a non-zero distance from the first cylindrical shell, and may be held in place by magnets or by any suitable support structure. The second cylindrical shell element 170 may upon rotation around the first cylindrical shell simply slide over the first cylindrical shell, or alternatively be supported by some support structure as it rotates around the first cylindrical shell.
The optical housing arrangement 100 is according to the invention suitable for housing optical equipment, such as optical sensors, cameras, detectors, light sources, lenses, polarization filters, etc. The optical housing arrangement 100 is according to the invention intended for use underwater, and may therefore house at least one light emitting device for illuminating an object of interest outside the optical housing arrangement 100, and at least one optical sensor in order to capture an image of the illuminated object. This setup results, however, in a problem with light pollution, i.e. where light goes straight from the light emitting device to the optical sensor inside the housing, or through the transparent portion of the first cylindrical shell without having gone via the object of interest outside the housing.
The self-cleaning optical housing arrangement may additionally be provided with electrical wiring in order to enable contact and/or power supply with any electrical and/or optical equipment within the optical housing arrangement. This wiring can for example go through any end cap of the housing arrangement, or alternatively be positioned in any other suitable spot. A slip ring may be used in order to transfer electricity to or in the optical housing arrangement.
The shaft 130 can in the context of the present invention generally take any form as long as it can rotate at least partly inside the inner volume 290 of the first cylindrical shell 110 relative to the first cylindrical shell 110.
Number | Date | Country | Kind |
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20190363 | Mar 2019 | NO | national |
Filing Document | Filing Date | Country | Kind |
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PCT/NO2020/050042 | 2/18/2020 | WO |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO2020/190144 | 9/24/2020 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
20130104933 | Aldred | May 2013 | A1 |
Number | Date | Country |
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106791323 | May 2017 | CN |
207057088 | Mar 2018 | CN |
2525386 | Oct 2015 | GB |
H10164289 | Jun 1998 | JP |
20170074923 | Jun 2017 | KR |
20110055099 | May 2011 | WO |
2014103726 | Jul 2014 | WO |
2016058105 | Apr 2016 | WO |
Entry |
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International Search Report and Written Opinion mailed in PCT/NO2020/050042 dated Aug. 5, 2020 (pages), 3 pages for search report, 6 pages for written opinion. |
Norwegian Search Report mailed in 20190363 dated Sep. 30, 2019 (2 pages). |
Number | Date | Country | |
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20220176416 A1 | Jun 2022 | US |