Protecting an optical device during operation

Abstract

An apparatus for protecting an optical device during operation is disclosed. The apparatus includes: a receptacle configured to receive the optical device, the receptacle including an optical surface generally rotationally symmetric about an axis of symmetry, wherein the optical surface extends non-orthogonally relative to the axis to radially enclose the optical device when the optical device is received in the receptacle; a seal including an engagement edge shaped generally complementary to the optical surface and held in engagement with it to seal against it, wherein the seal forms a continuous loop on the receptacle and includes a wiper portion that extends non-orthogonally to the axis of symmetry along the optical surface; and an actuator coupled between the receptacle and seal, configured to cause relative rotation about the axis between the receptacle and seal to cause the wiper portion to slide along the optical surface and dislodge contaminants from it.

Description

[0001] PROTECTING AN OPTICAL DEVICE DURING OPERATION

[0002] BACKGROUND

[0003] 1. Field

[0004] Embodiments of this disclosure relate to protecting an optical device and more particularly to protecting an optical device and maintaining a clear field of view during operation.

[0005] 2. Description of Related Art

[0006] Optical devices may have at least one optical surface exposed to the surrounding environment during operation. The optical surface may protect optical components enclosed within a housing. However, the optical surface may accumulate contaminants, such as, during use. In cases where the optical surface is exposed to a harsh environment the optical surface may become too quickly contaminated to rely on periodic manual cleaning. Some known devices for removing contaminants from the optical surface may allow buildup of contaminants, may require excessive maintenance, such as refilling of fluid or clogged nozzles, may not provide a good seal protecting the optical device from the surrounding environment, may be inefficient, may be costly, may leave excessive contamination in contact with the optical surface and / or may have other drawbacks.

[0007] SUMMARY

[0008] In accordance with various embodiments, there is provided an apparatus for protecting an optical device during operation, the apparatus including: a receptacle configured to receive the optical device, the receptacle including an optical surface, the optical surface being generally rotationally symmetric about an axis of symmetry, wherein at least a portion of the optical surface extends non- orthogonally relative to the axis of symmetry to radially enclose at least a portion of the optical device when the optical device is received in the receptacle; a seal including an engagement edge shaped generally complementary to the optical surface of the receptacle and held in engagement with the optical surface to seal against the optical surface, wherein the seal forms a continuous loop on the receptacle and includes a wiper portion that extends non-orthogonally to the axis of symmetry along the optical surface of the receptacle; and an actuator coupled between the receptacle and the seal, the actuator configured to cause relative rotation about the axis of symmetry between the receptacle and the seal to cause the wiper portion to slide along the optical surface and dislodge contaminants from the optical surface.

[0009] The seal may substantially surround the axis of symmetry.

[0010] The seal may form a continuous loop around the axis of symmetry.

[0011] The wiper portion may be disposed adjacent to a window extending at least 120 degrees about the axis of symmetry on the optical surface, the window configured to facilitate light transmission through the window to or from the optical device.

[0012] The window may extend at least 270 degrees about the axis of symmetry on the optical surface.

[0013] The wiper portion of the seal may extend at an angle of between 45 degrees and 135 degrees relative to a direction of travel of the optical surface or the wiper portion during relative rotation about the axis of symmetry between the receptacle and the seal.

[0014] The wiper portion of the seal may extend generally parallel with the axis of symmetry.

[0015] The wiper portion may include a wiper base, a wiper optical surface engager extending from the wiper base, the wiper optical surface engager including a wiper edge configured to engage with the optical surface, and a wiper hinge coupled between the wiper optical surface engager and the wiper base, the wiper hinge configured to facilitate rotation of the wiper optical surface engager relative to the wiper base.

[0016] The wiper hinge may have a reduced cross sectional thickness compared to at least a portion of the wiper optical surface engager.

[0017] The wiper edge may form an angle of between 70 degrees and 90 degrees.

[0018] The seal may include an applicator portion that extends non-orthogonally to the axis of symmetry along the optical surface of the receptacle, the applicator portion configured to slide along the optical surface and facilitate application of an optical layer medium to the optical surface.

[0019] The applicator portion of the seal may extend at an angle of between 45 and 135 degrees relative to a direction of travel of the optical surface or the applicator portion during relative rotation about the axis of symmetry between the receptacle and the seal.

[0020] The applicator portion of the seal may extend generally parallel with the axis of symmetry.

[0021] The applicator portion and the wiper portion of the seal may have generally the same cross-sectional shape.

[0022] The seal may have a generally constant cross-sectional shape throughout.

[0023] The optical surface may be generally cylindrical.

[0024] The optical surface may be generally spherical dome shaped. The optical surface may include an outer optical surface.

[0025] The apparatus may include a housing coupled between the seal and the actuator and holding the optical device, the housing configured to enclose the optical device in the receptacle when the optical device is received in the receptacle.

[0026] The seal may be a continuous loop of flexible material.

[0027] The seal may have a constant cross-sectional shape along the continuous loop.

[0028] The seal may follow a smooth curved path along the optical surface.

[0029] The seal may include a barrier portion that extends non-orthogonally to the axis of symmetry along the optical surface of the receptacle, the barrier portion extending for more than 120 degrees about the axis of symmetry on the optical surface and extending at a barrier angle of between 0.5 and 5 degrees relative to a plane normal to the axis of symmetry.

[0030] The barrier portion may extend for more than 270 degrees about the axis of symmetry on the optical surface.

[0031] The apparatus may include the optical device.

[0032] Other aspects and features of embodiments of the present disclosure will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the present disclosure in conjunction with the accompanying figures.

[0033] BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In drawings which illustrate embodiments of the present disclosure, Figure 1 is a side view of an optical system including an apparatus for protecting an optical device during operation, according to various embodiments;

[0035] Figure 2 is an isometric view of an optical surface and a seal of the apparatus shown in Figure 1 , in accordance with various embodiments;

[0036] Figure 3 is a a sectional view of the system shown in Figure 1 , according to various embodiments;

[0037] Figure 4 is an isometric view of a portion of the system in Figure 1 , in accordance with various embodiments;

[0038] Figure s is an isometric view of a portion of the system in Figure 1 , in accordance with various embodiments;

[0039] Figure 6 is a sectional view of a seal of the apparatus shown in Figure 1, in accordance with various embodiments;

[0040] Figure 7 is an enlarged view of part of the sectional view of the system shown in Figure 3, according to various embodiments;

[0041] Figure 8 is an isometric view of an apparatus for protecting an optical device during operation, according to various embodiments;

[0042] Figure 9 is an isometric view of a portion of the apparatus shown in Figure 8, according to various embodiments;

[0043] Figure 10 is an isometric view of an optical surface and a seal of an apparatus for protecting an optical device during operation, according to various embodiments; and Figure 11 is a side view of the optical surface and the seal shown in Figure 10, according to various embodiments.

[0044] DETAILED DESCRIPTION

[0045] In accordance with various embodiments, there is shown in Figure 1 , an optical system 100. The system 100 includes an optical device 110 and an apparatus 120 for protecting the optical device during operation. For example, in some embodiments, the optical device 110 may include a scanning LIDAR sensor, such as, for example, an Ouster OSO / OS1 scanning LIDAR. In accordance with other embodiments, various additional or alternative optical devices and / or sensors may be used. In some embodiments, the apparatus 120 may include the optical device 110

[0046] In various embodiments, the apparatus 120 may include a receptacle 200 configured to receive the optical device 110, the receptacle 200 including an optical surface 210, the optical surface being rotationally symmetric or generally rotationally symmetric about an axis of symmetry 212. In various embodiments, the optical surface 210 may be substantially optically transparent. Herein, "substantially optically transparent" should be taken to refer to a material that has a low attenuation of light passing through the optical surface to or from the optical device 110. In this context, the term "light" when used herein should be understood to refer to electromagnetic radiation having wavelengths in the visible, infrared, ultraviolet, or x-ray wavelength ranges. In some embodiments the wavelength range may be any of an ultraviolet range of wavelengths, a visible range of wavelengths, an infrared range of wavelengths, a long-wave infrared range of wavelengths, or an x-ray range of wavelengths. In various embodiments, the optical surface 210 may act as an outer optical surface that is subjected to contamination from an environment 101 within which the system 100 is operating. The apparatus 120 may also include a seal 240 in engagement with the optical surface 210.

[0047] Referring to Figure 2, the optical surface 210 of the receptacle 200 and the seal 240 are shown in further detail. In various embodiments, at least a portion of the optical surface 210 extends non-orthogonally relative to the axis of symmetry 212 to radially enclose at least a portion of the optical device (shown at 110 in Figure 1) when the optical device is received in the receptacle. In various embodiments, radial may refer to a direction outward from and perpendicular to the axis of symmetry 212. In various embodiments, the optical surface 210 may be generally cylindrical. In various embodiments, the receptacle 200 may include a transparent cylindrical enclosure, such as, for example, a glass cylinder. In some embodiments, the cylinder may be made of a chemically hardened borosilicate. In some embodiments, another transparent material may be used, such as, for example, fused silica, soda lime glass, sapphire, germanium (long-wave thermal application), polycarbonate, acrylic, and / or another material that is transmissible to the operating wavelength of the optical device 110. In various embodiments, coatings such as anti-reflective, anti-scratch, and / or other coatings may be used. In various embodiments, the cylinder may have the following dimensions: 108 mm OD, 100 mm height, and walls having 4 mm thickness. In some embodiments, the receptacle 200 may include a cap 220 enclosing one end of the cylinder shown in Figure 1. In some embodiments, the cap 220 may include a heat sink.

[0048] In various embodiments, the optical surface 210 extending non-orthogonally relative to the axis of symmetry 212 may facilitate use of the optical device 110 shown in Figure 1 to sense through the optical surface 210 around the optical device. In some embodiments, the optical surface 210 extending non-orthogonally relative to the axis of symmetry 212 may facilitate use of the optical device 110 to sense more than 120 degrees around the optical device 110, through the optical surface 210. For example, in some embodiments, the optical device 110 may be configured to sense more than 270 degrees around the optical device 110, through the optical surface 210. In some embodiments, the optical device 110 may be configured to sense more than 300 degrees around the optical device 110, through the optical surface 210. In various embodiments, this may be desirable to provide a large field of view for the optical device 110, which may be required in some applications of use for the optical device 110. In various embodiments, the optical surface 210 extending non-orthogonally relative to the axis of symmetry 212 may introduce challenges with keeping the optical surface 210 clean and / or removing contaminants from the optical surface.

[0049] Referring to Figure 1, the seal 240 includes an engagement edge shaped complementary or generally complementary to the optical surface 210 of the receptacle 200 and held in engagement with the optical surface 210 to seal against the optical surface.

[0050] Referring to Figure 2, the seal 240 is shown in engagement with the optical surface 210. In various embodiments, the seal 240 may form a continuous loop on the receptacle 200. In some embodiments, the seal 240 may form a continuous loop on the optical surface 210. For example, the engagement edge of the seal 240 may form a continuous loop in contact with the optical surface 210. In some embodiments, a continuous loop may facilitate sealed separation of an interior of the receptacle 200 or an interior of the housing from contaminants in the environment 101 that may be deposited on the optical surface 210. In various embodiments, the seal 240 forming a closed shape against the optical surface may prevent ingress of contaminants from the environment 101 into the receptacle 200 or housing.

[0051] In some embodiments, the seal 240 may include a wiper portion 242 that extends non-orthogonally to the axis of symmetry 212 along the optical surface 210. In some embodiments, the wiper portion 242 may be configured to slide along the optical surface 210 and dislodge contaminants from the optical surface 210. In various embodiments, the non-orthogonality of the wiper portion 242 to the axis of symmetry 212 may facilitate radial viewing via the optical device 110 shown in Figure 1 through the optical surface 210 while facilitating wiping or scraping of the optical surface 210 by the wiper portion 242.

[0052] In various embodiments, the wiper portion 242 may be disposed adjacent to a window 244 extending at least 120 degrees about the axis of symmetry 212 on the optical surface 210, the window configured to facilitate light transmission through the window to or from the optical device 110. In various embodiments, the window 244 extending at least 120 degrees about the axis of symmetry 212 may facilitate providing a wide field of view for the optical device 110. In some embodiments, a field of view of greater than 120 degrees may benefit from a curved optical surface rather than a flat optical surface, to reduce or avoid imaging distortions. In some embodiments, the window 244 may extend at least 270 degrees about the axis of symmetry 212 on the optical surface 210. In various embodiments, the wiper portion 242 may have an extent or position projected on the axis of symmetry 212 that corresponds to an extent or position of the window 244 projected on the axis of symmetry 212. Accordingly, the wiper portion 242 may be configured to slide along the window 244 and dislodge contaminants from the window 244. Referring to Figure 3, a sectional view of the system 100 shown in Figure 1 taken at the sectioning plane and in the direction indicated by section lines 3-3 shows an angular extent of the window 244 at 246. In some embodiments, the wiper portion 242 may extend at least 12.5 mm along the window 244, such that the window height is at least 12.5 mm. In some embodiments, the window 244 may have a height of about 80 mm, for example.

[0053] Referring to Figure 2, in some embodiments, the seal 240 may include a continuous loop of durable flexible material. For example, in some embodiments, the seal 240 may be composed of high-durometer polyurethane. In various embodiments, the continuous loop of durable flexible material may facilitate the seal having a continuous or generally continuous edge in contact with the receptacle 200 and / or the optical surface 210. In various embodiments, the seal 240 may include an applicator portion 250 that extends non-orthogonally to the axis of symmetry along the optical surface 210 of the receptacle 200, the applicator portion 250 configured to slide along the optical surface and facilitate application of an optical layer medium (“OLM”) to the optical surface 210.

[0054] Referring to Figure 3, the sectional view of the system 100 shown in Figure 1 taken at the sectioning plane and in the direction indicated by section lines 3-3 shows the cross sectional shape of the wiper portion 242 and the applicator portion 250 of the seal 240 shown in Figure 2 when the wiper portion 242 and the applicator portion 250 are engaged with the optical surface 210.

[0055] In some embodiments, OLM may be contained or held in an OLM reservoir 260 adjacent to the applicator portion 250 of the seal 240. In some embodiments, the OLM may include a material, such as a fluid, which is configured to coat the optical surface 210 and prevent or reduce strong adhesion of external contaminants to the optical surface 210. In some embodiments, the OLM may include a material having an index of refraction similar to that of the optical surface 210 (e.g., in some embodiments, an index of refraction similar to glass), which may in some embodiments reduce distortion. In some embodiments, the OLM may be applied to a cleaned (such as by the wiper portion 242) section of the optical surface 210 at every cleaning cycle. The OLM covering the optical surface 210 may help prevent contaminants from the environment 101 engaging directly with the optical surface 210, to facilitate their removal. In some embodiments, contaminants may land on the optical surface 210 on which the OLM has already been applied. In some embodiments, the OLM may be applied so thinly that it may not cover microscopic peaks of the optical surface 210. However, in some embodiments, the OLM may be sufficiently thick to cover microscopic peaks of the optical surface 210. In some embodiments, about 0.0002mL of fluid may be used per cycle (i.e., 360 degree relative rotation). In various embodiments, the surface roughness of the optical surface 210 may range between about 13nm to about 400nm depending on the degree of polishing. In other embodiments the application of OLM may be omitted.

[0056] In various embodiments, when an element or feature is described herein as abutting, contacting, or otherwise engaging with the optical surface 210, it is understood that the element or feature may be abutting contacting, or otherwise engaging OLM on the optical surface and thereby abutting, contacting or otherwise engaging with the optical surface 210 via the OLM.

[0057] Referring to Figure 4, in various embodiments, the apparatus 120 may include an actuator 280 coupled between the receptacle 200 and the seal 240, the actuator 280 configured to cause relative rotation about the axis of symmetry 212 between the receptacle 200 and the seal 240 to cause the wiper portion 242 of the seal 240 to slide along the optical surface 210 and dislodge contaminants from the optical surface 210.

[0058] Referring to Figure 1 , in some embodiments, the apparatus 120 may include a housing 320 coupled between the seal 240 and the actuator 280 (shown in Figure 4) and holding or mounted to the optical device 110, the housing 320 configured to enclose the optical device 110 in the receptacle 200 when the optical device 110 is received in the receptacle. In some embodiments, the housing 320 may be configured to hold the seal 240 in engagement with the receptacle 200. In various embodiments, the housing 320 may enclose and / or separate an interior of the receptacle 200 from outer contamination such that the optical device 110 is protected from outer contamination via a combination of the housing 320, the receptacle 200, and the seal 240 disposed between the housing 320 and the receptacle 200.

[0059] Referring to Figure 1, in various embodiments, the housing 320 may include a first housing 322 and a second housing 324. In some embodiments, the first housing 322 may act as an upper housing and the second housing 324 may act as a lower housing. In some embodiments, the housing 320 may be made of a strong rigid material, such as, for example, machined aluminum, stainless steel (which may be used for food-safe critical applications), and / or injection moulded plastic (which may be used in higher volume applications). Figure 4 depicts the system 100 with the first housing 322 removed for illustration purposes. Referring to Figure 4, in the embodiment shown, the actuator 280 includes first and second motors 360 and 362 coupled between the second housing 324 and the receptacle 200.

[0060] Figure 5 depicts the system 100 with the second housing 324 and the motors 360 and 362 from Figure 4 removed for illustration purposes. Referring to Figure 5, the motors 360 and 362 shown in Figure 4 may be coupled to drive gears 380 and 382. In various embodiments, the drive gears 380 and 382 may be meshed with an internal ring gear 400 mounted to the receptacle 200. In some embodiments, the internal ring gear 400 may be rotationally fixed to the glass cylinder having the optical surface 210. In some embodiments, the internal ring gear 400 may be fixed to the receptacle 200 via an adhesive, such as glue, for example. In the embodiment shown in Figures 4 and 5, two motors 360 and 362 are configured to deliver a drive torque via the drive gears 380 and 382 to the ring gear 400. In various embodiments, using two motors may provide a more compact implementation of the actuator 280 and / or may have the advantage of delivering a symmetrical drive to the ring gear 400 to balance the linear force applied to the ring gear. In other embodiments, the ring gear 400 may be driven by a single motor or more than two motors.

[0061] Referring to Figures 4 and 5, in various embodiments, in operation, the motors 360 and 362 may drive the drive gears 380 and 382 to cause the internal ring gear 400 and the receptacle 200 to rotate about an axis of rotation aligned with the axis of symmetry 212. In various embodiments, this may cause the optical surface 210 to rotate relative to the first and second housings 322 and 324 shown in Figure 1. In various embodiments, the second housing 324 may be fixedly coupled to the seal 240 for holding the seal 240 in engagement with the optical surface 210 and so rotation of the optical surface 210 relative to the second housing 324 may cause the optical surface 210 to rotate relative to the seal 240, in the direction shown by arrow 420 in Figures 3 and 4. In some embodiments, the actuator 280 may include a controller configured to provide electrical signals to the motors 360 and 362 for controlling the motors. In some embodiments, the controller may be configured to cause the motors 360 and 362 to be driven on a regular interval. For example, in some embodiments, the controller may drive the motors 360 and 362 to cause a 360 degree rotation about the axis of symmetry 212 between once per minute and once per day. In some embodiments, a 360 degree rotation or full revolution may take about 30 seconds to complete. In some embodiments, the controller may be disposed outside of the housing 320 and may communicate / control the motors via signals, such as, electrical signals delivered via electrical wires.

[0062] In various embodiments, the optical device 110 may be mounted to and rotationally fixed to the second housing 324 so that the optical surface 210 may rotate relative to the optical device 110.

[0063] During rotation of the optical surface 210 relative to the seal 240, the wiper portion 242 may dislodge contaminants from engagement with the optical surface 210 and / or OLM on the optical surface 210. In various embodiments, the dislodged contaminants may fall away from the optical surface 210. For example, in some embodiments, the axis of symmetry 212 may be aligned vertically or generally vertically and dislodged contaminants may fall downward and away from the optical surface 210. In various embodiments, after being wiped by the wiper portion 242, at least some of the OLM may remain on the optical surface.

[0064] Referring to Figure 2, in some embodiments, the seal 240 may substantially surround the axis of symmetry 212. In some embodiments, the seal 240 may be considered to substantially surround the axis of symmetry 212 when the seal 240 radially encloses at least 270 degrees of the axis of symmetry. In some embodiments, the seal 240 may form a continuous loop around the axis of symmetry 212. Accordingly, in various embodiments, the seal 240 completely surrounds the axis of symmetry 212. In various embodiments, the seal 240 surrounding the axis of symmetry 212 may facilitate use of a seal forming a continuous loop but having reduced or no opposing surfaces or edges facing the environment 101. In various embodiments, the seal surrounding the axis of symmetry 212 may facilitate mounting the system 100 shown in Figure 1 wherein the seal provides little or no exposed upper ledge to support or catch contaminants. Instead, in various embodiments, contaminants dislodged by the wiper portion 242 may fall away from the optical surface 210 without being caught and building up on any upper edge. For example, in some embodiments, the system 100 may be mounted such that the axis of symmetry 212 is aligned vertically or generally vertically and dislodged contaminants may fall away from the optical surface 210 without being caught by an edge of the seal 240 or another feature of the system 100. In other embodiments, the system 100 may be mounted such that the axis of symmetry 212 is aligned horizontally and the wiper portion 242 and the applicator portion 250 are on a lower side of the optical surface 210 and in this configuration, dislodged contaminants may fall away from the optical surface 210 without being caught by an edge of the seal 240 or another feature of the system 100. In various embodiments, other mounting orientations and / or configurations may be used.

[0065] Referring to Figure 2, in various embodiments, the wiper portion 242 of the seal 240 may extend at an angle of between 45 degrees and 135 degrees relative to a direction of travel of the optical surface 210 or the wiper portion 242 during relative rotation about the axis of symmetry 212 between the receptacle 200 and the seal 240. In some embodiments, this may facilitate providing a large field of view for the window 244 for the optical device 110. In the embodiment shown in Figure 2, the wiper portion 242 extends at an angle of about 90 degrees relative to a direction of travel of the optical surface 210 relative to the wiper portion 242 during relative rotation about the axis of symmetry 212 between the receptacle 200 and the seal 240. Accordingly, in the embodiment shown, the wiper portion 242 of the seal 240 extends in a plane that includes the axis of symmetry 212. In various embodiments, this may facilitate simplicity of design and manufacturing, a large field of view for the window 244, efficient dislodging of contaminants from the optical surface 210, reduced ingress of contaminants past the seal 240 and / or reduced supporting or catching surfaces on the seal 240 for the dislodged contaminants.

[0066] In some embodiments, the wiper portion 242 of the seal 240 may extend parallel or generally parallel with the axis of symmetry 212. In various embodiments, this may facilitate simplicity of design and manufacturing, a large field of view for the window 244, efficient dislodging of contaminants from the optical surface 210, reduced ingress of contaminants past the seal 240, reduced supporting or catching surfaces on the seal 240 for the dislodged contaminants, and / or use of the apparatus 120 with a cylindrical optical surface. In some embodiments, such an arrangement may be used in combination with vertical alignment of the axis of symmetry 212, such that the wiper portion 242 of the seal 240 is vertically aligned, and this may facilitate contaminants falling downward away from the optical surface 210 and the wiper portion 242 of the seal 240.

[0067] Referring to Figure 2, in various embodiments, the seal 240 may include a first barrier portion 440 coupled between the wiper portion 242 and the applicator portion 250 of the seal 240. In various embodiments, the first barrier portion 440 may be disposed adjacent to the window 244 and / or above the window 244. In various embodiments, the first barrier portion 440 may be held by the housing 320 in engagement with the optical surface 210 to prevent ingress of contaminants from the environment 101 into the housing 320 and / or receptacle 200. In various embodiments, the first barrier portion 440 may follow an arc that is centered about the axis of symmetry 212. In some embodiments, the first barrier portion 440 may lie in a plane normal to the axis of symmetry 212. In some embodiments, the seal 240 may include a second barrier portion 442 coupled between the wiper portion 242 and the applicator portion 250 of the seal 240. In various embodiments, the second barrier portion 442 may be rotationally spaced apart from first barrier portion 440 and the window 244. For example, in various embodiments, the second barrier portion 442 may be at a position rotationally displaced about the axis of symmetry 212 relative to the first barrier portion 440 and the window 244. In various embodiments, the second barrier portion 442 may be held by the housing 320 in engagement with the optical surface 210 to prevent ingress of contaminants from the environment 101 into the housing 320 and / or receptacle 200. In various embodiments, the second barrier portion 442 may follow an arc that is centered about the axis of symmetry 212 and in various embodiments, the second barrier portion 442 may lie in a plane normal to the axis of symmetry 212.

[0068] In various embodiments, continuity between the wiper portion 242 and the applicator portion 250 of the seal 240 through the first barrier portion 440 and the second barrier portion 442 may prevent or reduce the intrusion of contaminants into the space between the housing 320 and / or the seal 240 and the optical surface. Intrusion of contaminants combined with the relative movement of the housing and / or the wiper portion and the applicator portion of the seal may scratch and damage the optical surface leading to a progressively worsening intrusion of the contaminants, leading to complete failure of the self-cleaning function, and the optical surface.

[0069] In various embodiments, the seal 240 may follow a smooth curved path along the optical surface 210. In various embodiments, the seal 240 may include a first wiper transition 460 between the wiper portion 242 and the first barrier portion 440. In some embodiments, the first wiper transition 460 may include a smooth curve between the first barrier portion 440 and the wiper portion 242. For example, in some embodiments, the curve may follow an arc projected on the optical surface 210. In some embodiments, the arc may have a radius of about 3x the cross- sectional width of the seal. In some embodiments, the arc may have a radius of at least 6 mm. In some embodiments, the arc may have a radius of between about 6 mm and about 15 mm. In some embodiments, the arc may facilitate bending the seal 240 without problematic distortion of its cross-section. In some embodiments, an arc, such as an arc having a radius of at least about 6 mm may facilitate strong engagement of the seal 240 with the optical surface 210 and may prevent or reduce lifting of the seal 240 off of the optical surface 210. In some embodiments, too large of a radius of curvature may be undesirable because it may reduce the field of view provided for the optical device 110 through the optical surface 210. In some embodiments, use of a curve may facilitate reduced costs and / or ease of manufacturing the seal 240.

[0070] In various embodiments, the seal 240 may include a second wiper transition 462 between the wiper portion 242 and the second barrier portion 442. In some embodiments, the second wiper transition 462 may include a smooth curve between the wiper portion 242 and the second barrier portion 442. For example, in some embodiments, the curve may follow an arc projected on the optical surface 210. In some embodiments, the curve may have generally similar properties and advantages to other curves in the seal 240, such as the curve at the first wiper transition 460 described herein. In some embodiments, the arc may have a radius of at least 6 mm. In some embodiments, the arc may have a radius of between about 6 mm and about 15 mm. In various embodiments, the seal 240 may follow a smooth curved path along the optical surface 210 wherein a radius of curvature of the path is at least 6 mm throughout the path of the seal 240.

[0071] In various embodiments, the first and second wiper transitions 460 and 462 may act as second and third wiper portions and may assist in removing contaminants from the optical surface 210 during operation. In various embodiments, the wiper portion 242 may follow a curved path on the optical surface 210. Referring to Figure 6, a sectional view of the seal 240 shown in Figure 1 taken at the same location as the sectioning plane and in the direction indicated by section lines 3-3 in Figure 1 shows the cross sectional shape of the wiper portion 242 and the applicator portion 250 of the seal 240 when the wiper portion 242 and the applicator portion 250 are not engaged with the optical surface 210. As can be seen from comparing the wiper portion 242 in Figures 3 and 6, in operation, as shown in Figure 3, the wiper portion 242 of the seal 240 is caused to flex or deform when held in engagement with the optical surface 210. In various embodiments, the flexing or deformation may be a resilient flexing or deformation of the wiper portion 242 that provides a force that urges the wiper portion 242 into contact with the optical surface 210. In various embodiments, this flexing or deformation may be desirable to maintain consistent engagement with the optical surface 210, which may be uneven given that it may be practically challenging to produce optical surfaces such as glass cylinders with a tight dimensional tolerance. In various embodiments, the flexing or deformation may be desirable to generate pressure on the optical surface 210.

[0072] In various embodiments, the wiper portion 242 may include a wiper base 480 and a wiper optical surface engager 482 extending from the wiper base 480. In operation, the wiper base 480 may be held by the second housing 324 in engagement with the optical surface 210, as shown in Figures 3 and 4, for example. In various embodiments, the wiper optical surface engager 482 may include a wiper blade or arm extending from the wiper base 480. In various embodiments, the wiper optical surface engager 482 may include a wiper edge 484 configured to engage with or abut the optical surface 210 (as shown in Figures 3 and 7, for example).

[0073] Referring to Figure 6, in some embodiments, an angle 485 formed by the wiper edge 484 may be chosen so that the cross-sectional shape of the seal 240 works well as both a wiper in the wiper portion 242 and as an applicator in the applicator portion 250. Referring to Figure 7, the wiper portion 242 engaging with the optical surface 210 as shown in Figure 3 is shown in further detail. In some embodiments, it may be desirable for dislodging contaminants that the wiper optical surface engager 482 and the wiper edge 484 form an angle 487 as shown in Figure 7 of about 90 degrees with the optical surface 210 when the wiper edge 484 engages with the optical surface 210. In various embodiments, the angle 487 may be less than 110 degrees, which may, in some embodiments facilitate the wiper optical surface engager 482 forming a rigid column that must be buckled for contaminants to pass through. In some embodiments, the angle 487 may be greater than 80 degrees, which may, in some embodiments facilitate the wiper optical surface engager 482 lifting and removing contaminants from the optical surface 210. In some embodiments, if the angle 485, as shown in Figure 6, of the wiper edge 484 were to be too small (i.e. less than 70 degrees) the wiper optical surface engager 482 may lack strength to resist pressure from contaminants and could fold locally to allow contaminants to pass through. In various embodiments, balancing the wiping, application, and manufacturing considerations of the seal 240 may take considerable design, simulation and experimentation. In some embodiments, the wiper edge 484 may form the angle 485 of between 70 degrees and 90 degrees. The wiper optical surface engager 482 may be configured to contact the optical surface 210 along a line of contact or contact line at the wiper edge 484.

[0074] Referring to Figure 6, the wiper portion 242 may include a wiper hinge 490 coupled between the wiper optical surface engager 482 and the wiper base 480, the wiper hinge configured to facilitate rotation of the wiper optical surface engager 482 relative to the wiper base 480. In various embodiments, the wiper hinge 490 may facilitate the wiper portion 242 functioning with large variation in diametric tolerance of the optical surface 210, while maintaining relatively consistent pressure. In various embodiments, the wiper hinge 490 may be configured to facilitate compliant flexing of the wiper portion 242 in the region of the wiper hinge.

[0075] In some embodiments, the wiper hinge 490 may have a reduced cross-sectional thickness compared to at least a portion of the wiper optical surface engager 482. For example, in some embodiments, the wiper hinge 490 may include a relief notch or cut 492. In various embodiments, the wiper hinge 490 may have a cross- sectional thickness about 70% of the largest cross-sectional thickness of the wiper optical surface engager 482. In various embodiments, the cross-sectional thickness difference may facilitate desired contact pressure, while maintaining a relatively flat wiper optical surface engager 482.

[0076] In various embodiments, the wiper hinge 490 may facilitate biased rotation of the wiper optical surface engager 482 relative to the wiper base 480, while maintaining a straight or generally straight, rigid wiper optical surface engager 482 contacting the optical surface 210. In some embodiments, this may facilitate the wiper edge 484 contacting the optical surface 210 or OLM on the optical surface 210 via a line or edge contact rather than a surface contact. In some embodiments, if the wiper optical surface engager 482 is allowed to flex or bend too much, the line contact with the optical surface 210 may become a surface contact near the wiper edge 484. A surface contact may lead to lifting of the wiper edge 484 of (e.g., a microscopic lifting), which in turn may allow small particles to wedge and pass under the wiper edge 484. In various embodiments, the wiper hinge 490 may facilitate keeping rigidity in the wiper optical surface engager 482 in the direction tangent to the optical surface 210, while allowing deflection normal to the optical surface. In some embodiments, maintaining stiffness relative to the relative direction of motion (tangent to glass) may facilitate prevention or reduction of particles with some adhesion pushing through or past the wiper edge 484.

[0077] In various embodiments, the wiper base 480, the wiper optical surface engager 482 and the wiper hinge 490 may be integral to one another. For example, in some embodiments, the wiper base 480, the wiper optical surface engager 482 and the wiper hinge 490 may be formed from a single piece of flexible material, such as high-durometer polyurethane. In various embodiments, the wiper base 480, the wiper optical surface engager 482 and the wiper hinge 490 being integral may facilitate ease of manufacturing and / or sealing performance of the wiper portion

[0078] 242

[0079] Referring back to Figures 3 and 4, in operation of the embodiment shown, as the optical surface 210 rotates relative to the seal 240 in the direction shown by the arrow 420, OLM held in the OLM reservoir 260 adjacent to the applicator portion 250 of the seal 240 may be applied or deposited on the optical surface 210 in a thin coating or film by the applicator portion 250 of the seal 240. In various embodiments the OLM may be applied as a liquid film and the applicator portion 250 and the reservoir 260 may be configured to primarily perform the function of dispensing a thin and substantially uniform film on the optical surface 210. Various advantages provided by the application of the OLM to the optical surface 210, in accordance with some embodiments, are described above and herein. In various embodiments, the reservoir 260 may be surrounded and protected from the environment 101 by the seal 240. In some embodiments, this may facilitate protecting and keeping the reservoir and OLM contained therein clean in dirty environments. In various embodiments, the second housing 324 may include a selectively open-able reservoir inlet 450 shown in Figure 4 for filling or refilling the reservoir 260.

[0080] In various embodiments, the applicator portion 250 of the seal 240 may extend at an angle of between 45 degrees and 135 degrees relative to a direction of travel of the optical surface 210 or the applicator portion 250 during relative rotation about the axis of symmetry 212 between the receptacle 200 and the seal 240. In some embodiments, this may facilitate providing a large field of view for the window 244 for the optical device 110. In the embodiment shown in Figure 2, the applicator portion 250 extends at an angle of about 90 degrees relative to a direction of travel of the optical surface 210 relative to the applicator portion 250 during relative rotation about the axis of symmetry 212 between the receptacle 200 and the seal 240. Accordingly, in the embodiment shown, the applicator portion 250 of the seal 240 extends in a plane that includes the axis of symmetry 212. In various embodiments, the applicator portion 250 of the seal 240 may extend parallel or generally parallel with the axis of symmetry 212. In various embodiments, having the applicator portion 250 extend in a plane that includes the axis of symmetry 212 and / or parallel with the axis of symmetry may facilitate simplicity of design and manufacturing, a large field of view for the window 244, and / or reduction of the extent of the optical surface 210 that is blocked by the region between the applicator portion 250 and the wiper portion 242.

[0081] Referring to Figure 2, in various embodiments, the seal 240 may include a first applicator transition 464 between the applicator portion 250 and the first barrier portion 440. In some embodiments, the first applicator transition 464 may include a smooth curve between the first barrier portion 440 and the applicator portion 250. For example, in some embodiments, the curve may follow an arc projected on the optical surface 210. In some embodiments, the curve may have generally similar properties and advantages to other curves in the seal 240, such as the curve at the first wiper transition 460 described herein. In some embodiments, the arc may have a radius of at least 6 mm. In some embodiments, the arc may have a radius of between about 6 mm and about 15 mm.

[0082] In various embodiments, the seal 240 may include a second applicator transition 466 between the applicator portion 250 and the second barrier portion 442. In some embodiments, the second applicator transition 466 may include a smooth curve between the applicator portion 250 and the second barrier portion 442. For example, in some embodiments, the curve may follow an arc projected on the optical surface 210. In some embodiments, the curve may have generally similar properties and advantages to other curves in the seal 240, such as the curve at the second wiper transition 462 described herein. In some embodiments, the arc may have a radius of at least 6 mm. In some embodiments, the arc may have a radius of between about 6 mm and about 15 mm. In various embodiments, the first and second applicator transitions 464 and 466 462 may act as second and third applicator portions and may assist in depositing OLM on the optical surface 210 during operation. In various embodiments, the applicator portion 250 may follow a curved path on the optical surface 210.

[0083] Referring to Figure 5, in various embodiments, the apparatus 120 may include an OLM seal 500 disposed between the second housing 324 and the receptacle 200. In various embodiments, the OLM seal 500 may separate the reservoir 260 from part of the interior of the first housing 322 and thereby the interior of the receptacle 200. Accordingly, in various embodiments, the OLM seal 500 may reduce or prevent OLM from leaking out of the reservoir 260 and contacting sensitive parts of the apparatus 120, such as, for example, any or all of the motors 360 and 362, the gears 380, 382, and 400, and / or the optical device 110. In some embodiments, the OLM seal 500 may include a flexible o-ring held against an outer surface of the receptacle 200 by the second housing 324. In some embodiments, the OLM seal 500 may be held rotationally with the second housing 324. In some embodiments, other seals may be used in place of the OLM seal 500, such as, for example, a standard rotary seal, including swivel seals, clipper seals, or another seal.

[0084] Referring to Figures 3 and 6, the applicator portion 250 shown in Figures 1 and 3, in operation is flexed or deformed when held in engagement with the optical surface 210. In various embodiments, this flexing or deformation may be desirable to maintain a consistent line contact engagement with the optical surface 210, which may be uneven given that it may be practically challenging to produce optical surfaces such as glass cylinders with a tight dimensional tolerance. In various embodiments, line contact engagement may maintain OLM thickness control practically independent of application speed.

[0085] In various embodiments, the applicator portion 250 and the wiper portion 242 of the seal 240 may have the same or generally the same cross-sectional shape. In some embodiments, the seal 240 may have a constant or generally constant cross- sectional shape throughout. Accordingly, in some embodiments, the cross- sectional shape may remain constant along the length or circumference of the seal 240, including at the applicator portion 250 and the wiper portion 242. In some embodiments, this common cross sectional shape may facilitate ease of manufacturing of the seal 240.

[0086] Referring to Figure 6, in various embodiments, the applicator portion 250 may include an applicator base 580 and an applicator optical surface engager 582 extending from the applicator base 580. In operation, the applicator base 580 may be held by the second housing 324 in engagement with the optical surface 210, as shown in Figures 3 and 4, for example. In various embodiments, the applicator optical surface engager 582 may include an applicator blade or arm extending from the applicator base 580. In various embodiments, the applicator optical surface engager 582 may include an applicator edge 584 configured to engage with or come into contact with the optical surface 210 (as shown in Figure 3, for example).

[0087] In some embodiments, the applicator portion 250 may include an applicator hinge 590 coupled between the applicator optical surface engager 582 and the applicator base 580. In various embodiments, the applicator hinge 590 may facilitate the applicator portion 250 functioning with large variation in diametric tolerance of the optical surface 210, while maintaining relatively consistent pressure.

[0088] In some embodiments, the applicator hinge 590 may have a reduced thickness compared to at least a portion of the applicator optical surface engager 582. For example, in some embodiments, the applicator hinge 590 may include a relief notch or cut 592.

[0089] In various embodiments, the applicator hinge 590 may facilitate biased rotation of the applicator optical surface engager 582 relative to the applicator base 580, while maintaining a straight or generally straight, rigid applicator optical surface engager 582 contacting the optical surface 210. In some embodiments, this may facilitate the applicator edge 584 contacting the optical surface 210 or OLM on the optical surface 210 via a line or edge contact rather than a surface contact.

[0090] A combination of pressure against the optical surface 210 and a departure or relief angle between a trailing surface of the applicator optical surface engager 582 and the optical surface 210, has been shown to allow a release quantity of OLM suitable for forming a desired thickness film on the optical surface as the optical surface 210 passes past the applicator portion 250 of the seal 240. In some embodiments, the departure angle may be the main geometric parameter determining OLM thickness. In some embodiments, the departure angle may be about 10-30 degrees when the applicator optical surface engager 582 engages with the optical surface 210. For example, in some embodiments, the departure angle may be about 15 degrees when the applicator optical surface engager 582 engages with the optical surface 210.

[0091] In some embodiments, the angle 585 formed by the applicator edge 584 may determine, at least in part, the departure angle. As set out above, the angle 585 formed by the applicator edge 584 may be chosen so that the cross-sectional shape works well as both an applicator and a wiper. In various embodiments, the applicator edge 584 may form the angle 585 of between about 70 and 90 degrees.

[0092] In various embodiments, the applicator base 580, the applicator optical surface engager 582 and the applicator hinge 590 may be integral to one another. For example, in some embodiments, the applicator base 580, the applicator optical surface engager 582 and the applicator hinge 590 may be formed from a single piece of flexible material. In various embodiments, the applicator base 580, the applicator optical surface engager 582 and the applicator hinge 590 being integral may facilitate ease of manufacturing and / or sealing performance of the applicator portion 250. In some embodiments, the seal 240 may be machined (such as by a lathe) first as a circular element, which may facilitate forming the wiper edge 484 and the wiper optical surface engager 482 with reduced imperfections at the engagement edge or surface. In some embodiments, the seal 240 being machined (such as by a lathe) first as a circular element may facilitate forming the applicator edge 584 and the applicator optical surface engager 582 with reduced imperfections at the engagement edge or surface. In various embodiments, the constant cross- sectional shape of the seal 240 may facilitate manufacture of the seal by lathe.

[0093] Various embodiments

[0094] In some embodiments, an apparatus generally similar to the apparatus 120 shown in Figure 1 may include a receptacle having an optical surface having a different shape, such as, for example, an optical surface including a spherical dome shape, a hemisphere, a frustoconical shape, or another shape generally rotationally symmetric about the axis of symmetry 212.

[0095] Referring to Figure 8, there is shown an apparatus 620 generally similar to the apparatus 120 shown in Figure 1 except that an optical surface 710 of the apparatus 620 is shaped at least in part as a spherical or a generally spherical dome. In various embodiments, the apparatus 620 may include a receptacle 700 configured to receive an optical device 610, the receptacle 700 including the optical surface 710, the optical surface being rotationally or generally rotationally symmetric about an axis of symmetry 712. In various embodiments, the apparatus 620 may include a housing 820.

[0096] Referring to Figure 9, the receptacle 700 is shown without an outer portion of the housing 820, for illustration purposes. In various embodiments, at least a portion of the optical surface 710 may extend non-orthogonally relative to the axis of symmetry 712 to radially enclose at least a portion of the optical device 610 when the optical device is received in the receptacle. In various embodiments, the optical surface 710 may be spherical or generally spherical dome shaped or hemispherical. In various embodiments, the receptacle 700 may include a transparent spherical dome enclosure, such as, for example, a glass hemisphere. In some embodiments, the diameter of the receptacle 700 may be about 100 mm and the wall thickness may be about 4 mm. In some embodiments, the receptacle 700 may include some of the same materials and properties of the receptacle 200 described herein having regard to Figures 1-7.

[0097] In some embodiments, use of the spherical dome shape of the receptacle 700 may, for optical devices having a large field of view in the direction aligned with the axis 712, reduce distortion / attenuation of a scan at the extreme edges (e.g., top / bottom) of the field of view, which may be caused by a large angle of incidence that may arise when using a cylindrical receptacle, for example. In various embodiments, in the spherical case, the angle of incidence may be near 0 for all rays. In some embodiments, the spherical dome shape of the receptacle 700 may be required when a vertical field of view or field of view in the direction aligned with the axis 712 exceeds 90 degrees, for example.

[0098] Referring to Figure 9, the apparatus 620 may include a seal 740 including an engagement edge shaped complementary or generally complementary to the optical surface 710 of the receptacle 700 and held in engagement with the optical surface 710 to seal against the optical surface. In various embodiments, the seal 740 may include generally similar features to that of the seal 240 described herein with reference to Figures 1-7.

[0099] In various embodiments, the seal 740 may form a continuous loop on the receptacle 700. In some embodiments, the seal 740 may form a continuous loop on the optical surface 710. For example, the engagement edge of the seal 740 may form a continuous loop on the optical surface 710. In some embodiments, a continuous loop may facilitate sealed separation of an interior of the receptacle 700 and / or reduced ingress of outer contaminants. In various embodiments, the seal 740 may have generally similar properties to some properties of the seal 240 described herein having regard to Figures 1-7.

[0100] In some embodiments, the seal 740 may include a wiper portion 742 that extends non-orthogonally to the axis of symmetry 712 along the optical surface 710, the wiper portion 742 configured to slide along the optical surface 710 and dislodge contaminants from the optical surface 710. In various embodiments, the wiper portion 742 may have generally similar properties to some properties of the wiper portion 242 described herein having regard to Figures 1-7.

[0101] In various embodiments, the apparatus 620 may include an actuator 780 coupled between the receptacle 700 and the seal 740, the actuator 680 configured to cause relative rotation about the axis of symmetry 712 between the receptacle 700 and the seal 740 to cause the wiper portion 742 of the seal 740 to slide along the optical surface 710 and dislodge contaminants from the optical surface 710. In various embodiments, the actuator 780 may be generally similar to the actuator 280 described herein having regard to Figures 1-7.

[0102] Still referring to Figure 9, in various embodiments, the seal 740 may include an applicator portion 750 that extends non-orthogonally to the axis of symmetry along the optical surface 710 of the receptacle 700, the applicator portion 750 configured to slide along the optical surface and facilitate application of OLM to the optical surface 710. In various embodiments, the applicator portion 750 may have generally similar properties to some properties of the applicator portion 250 described herein having regard to Figures 1-7.

[0103] In operation, motors of the actuator 780 may drive the drive gears to cause the receptacle 700 to rotate about an axis of rotation aligned with the axis of symmetry 712. In operation, the wiper portion 742 and the applicator portion 750 may perform wiping of the optical surface 710 and application of OLM generally as described herein having regard to the apparatus 120 shown in Figures 1-7. In various embodiments, an apparatus generally similar to the apparatus 120 or the apparatus 620 shown in Figures 1 and 8 may include additional or alternative reservoir(s) and / or dispenser(s) of OLM applied by the applicator portion of the seal, compared to the reservoir 260 described herein. For example, in some embodiments, an apparatus generally similar to the apparatus 120 or the apparatus 620 shown in Figures 1 and 7 may include a reservoir having an absorbent material for holding the OLM. For example, the absorbent material may be a textile material such as felt having a bulk volume that may be saturated with the OLM. In some embodiments, the absorbent material may be placed in fluid communication with an OLM reservoir, in which case the absorbent material may act as a wick for conveying liquid between the reservoir and the optical surface.

[0104] In some embodiments, an apparatus generally similar to the apparatus 120 or the apparatus 620 shown in Figures 1 and 8 may include a reservoir having a sprayer having a nozzle oriented toward the optical surface. When the optical surface moves relative to the reservoir and nozzle, liquid from the reservoir may be sprayed through the nozzle directly onto the optical surface. In various embodiments, the sprayer may be surrounded and protected from the environment by a seal generally similar to the seal 240. In some embodiments, this may facilitate protecting and keeping the nozzle of the sprayer clean in dirty environments. An amount of liquid dispensed may be controlled by a controller configured to control operation of the sprayer. In one embodiment the sprayer may be implemented as a plurality of piezoelectric or thermally excited nozzles, such as used in inkjet printers.

[0105] In accordance with various embodiments, suitable liquids for the OLM, may have properties that cause the liquid to uniformly wet the optical surface. The suitable liquids may remain stable under environmental conditions that the apparatus will be subjected to. It may also be desirable that adhesive forces between the liquid and the optical surface are greater than adhesive forces between the liquid and typical contaminants. Under these conditions many typical contaminant particles will tend to float within the liquid film rather than adhere to the optical surface. Accordingly, in these conditions the OLM will generally remain concentrated between the contaminants and the optical surface, weakening bonding between the contaminants and the optical surface, allowing the wiper portion to lift the contaminants away from the optical surface rather than rubbing them against the optical surface. Other liquid properties that may be desirable depending on the application include stable viscosity, low vapor pressure, and hydrolytic stability.

[0106] In some embodiments, the OLM may be a liquid such as a hydraulic oil. In some embodiments the hydraulic oil may include constituents such as silicone that cause the liquid film to have hydrophobic characteristics, which reduces the likelihood of water becoming entrained within the liquid film. These liquids will tend to cause water droplets to float on top of the liquid film, where they can be easily removed by the wiper portion 242 shown in Figures 1-7, for example, rather than pass under the wiper portion. Additionally, the liquid may also have suitable optical properties. As an example, the liquid may be selected based on high optical transmittance over a wavelength range associated with the optical device 110, for example. The liquid may also be selected to have a refractive index that is close to a refractive index of the material of the receptacle 200 forming the optical surface 210, which reduces the optical effect of scratches in the optical surface 210, for example.

[0107] In some embodiments, the OLM may remain in the liquid state after being dispensed on the optical surface and may cause a negligible or minor degradation to images captured through the OLM. In other embodiments the selected OLM may at least partly cure after being dispensed. In some embodiments, the OLM may include a non-liquid material and the OLM may at least partially evaporate after being dispensed, leaving the non-liquid material on the optical surface.

[0108] In some embodiments a non-liquid material may be dispensed by being abraded from the applicator portion of the seal to form the film during the relative rotation. As an example, the entire seal or the applicator portion of the seal may be fabricated from a material that when dragged across the optical surface leaves a film behind. One example of such materials are polysiloxane based materials, which may be fabricated in various forms and may include cross-linked polymers that may be used as a sealing element.

[0109] In some embodiments, the optical device may include one or more optical elements configured to redirect light, such as a mirror or lens, disposed within the receptacle, and an optical sensor disposed out of the receptacle.

[0110] In various embodiments, any or all of the optical devices described herein, such as the optical device 110 shown in Figure 1 or the optical device 610 shown in Figures 8 and 9, may include additional or alternative optical elements, such as, optical sensors and / or lights. For example, in some embodiments, the optical device may include a camera, a rangefinder, and / or another optical device having at least one optical surface exposed to the surrounding environment.

[0111] In any of the embodiments described herein with reference to an optical device having a sensor for receiving light, it should be appreciated that the optical device may alternatively include a light source that generates light and directs the light out through the clear aperture. The optical device may thus include illuminators such as a light emitting diode or laser or the like. Furthermore, the sensor may be configured for generating an image (for example, a CMOS image sensor) but may also be a photo-sensor or other detector configured to generate a signal in response to an intensity of light captured or variations in frequency or phase of light impinging on the sensor. In some embodiments there may be multiple optical devices received in the receptacle 200 or the receptacle 700 shown in Figures 1 and 8. The optical device 110 or the optical device 610 shown in Figures 1 and 8 may include any combination of electromagnetic radiation emitters or detectors, or multiples thereof. One example would be a camera and a light source for illuminating the field of view of the camera. Another example would be a light source such as a laser or light emitting diode and a photodetector that senses electromagnetic radiation reflected back through the optical surface.

[0112] In various embodiments, a system generally similar to the system 100 shown in Figure 1 or including an apparatus generally similar to the apparatus 620 shown in Figure 8 may include an optical device configured to sense other non-optical electromagnetic radiation and the system may be configured to sense other non- optical electromagnetic radiation.

[0113] In various embodiments, an apparatus generally similar to the apparatus 120 shown in Figure 1 or the apparatus 620 shown in Figure 8 may include additional or alternative wiper portions. For example, in some embodiments the wiper portion 242 may be fabricated from compliant material such as polyurethane. In some embodiments, use of less compliant or non-compliant materials for the wiper portion 242 (such as, for example, polyethylene (UFIMW), or acetal or Delrin®) may require a compliant backing material (e.g., a polyurethane gasket) to provide the pressure on the optical surface 210 and to allow compliance against optical surface variation. In some embodiments the material of the seal may be further treated to further improve its properties to prevent the likelihood of contaminants building up and becoming attached to the seal. In some embodiments, the second housing 324, the wiper portion 242, the applicator portion 250, and / or other portions of the seal 240 shown in Figure 1 or similar elements of the apparatus 620 shown in Figure 8 may include a low-friction coating applied thereto to limit the amount of contamination buildup following repeated self-cleaning cycles.

[0114] Some contaminant particles may adhere directly to the optical surface and these contaminant particles may be more difficult to dislodge. Additionally, some tenacious contaminants, such as tree sap or resin, can be very difficult to dislodge once adhered to the optical surface. In embodiments where the likely contaminants include these more tenacious contaminants, at least a portion of the wiper portion may be fabricated from a metallic material. For example, the wiper portion may include a metallic material such as a brass alloy, stainless steel alloy, or a porous metal alloy impregnated with a lubricant.

[0115] As described herein, in some embodiments, the applicator portion 250 and the wiper portion 242 of the apparatus 120 shown in Figures 1-7 may be portions of the same seal 240, with the only difference being that the seal 240 is mirrored with respect to the direction of movement of the optical surface 210, when comparing the applicator portion 250 and the wiper portion 242. However, in some embodiments, an apparatus generally similar to the apparatus 120 shown in Figures 1-7 may include an applicator that is separate from a wiper. For example, in some embodiments, the applicator may include a seal on an optical surface that is completely surrounded by a wiper seal on the optical surface. In some embodiments, the applicator may include a seal that forms a continuous loop around the axis of symmetry on the receptacle similar to the seal 240 shown in Figures 1-7, but still internal to a wiper seal. In some embodiments, this may be desirable if the application of OLM requires an effective hermetic seal in an explosive environment, and / or this may be desirable when the primary seal is made from a non-compliant material (and is therefore unable to effectively regulate the OLM), for example; in such embodiments, a more compliant seal, such as an O-ring, may be used as the applicator seal, which may create a more effective seal than the seal 240 shown in Figures 1-7. In some embodiments, the applicator may include an applicator seal including an internal lip, attached to a seal generally similar to the seal 240 at the applicator portion. In some embodiments an applicator may form a continuous loop that does not surround the axis of symmetry / rotation, but still remains fully internal to a wiper seal. In some embodiments, this separation of the applicator and wiper may be desirable when the design parameters of a suitable wiper conflicts with the design parameters of a suitable OLM applicator. An example of this scenario is when the design of the wiper requires a substantially less compliant material compared to what would be suitable for an OLM applicator In various embodiments, application of OLM may be omitted from a system generally similar to the system 100 shown in Figures 1-7 or the apparatus 620 shown in Figures 8 and 9. In such embodiments, for example, the reservoir (e.g., the reservoir 260 of the apparatus 120) may be omitted and / or left empty.

[0116] In some embodiments, the applicator portion 250 of the seal 240 shown in Figures 1-7 may be parallel or generally parallel to the wiper portion 242. In some embodiments, the seal 240 may be generally symmetric and mirrored between the applicator portion 250 and wiper portion 242 such that the seal 240 may be rotated in either direction relative to the optical surface 210. In such embodiments, when the seal 240 rotates in the opposite direction, the applicator portion 250 may act as a wiper and the wiper portion 242 may act as an applicator.

[0117] In some embodiments, an apparatus that functions generally similarly to the apparatus 120 shown in Figures 1-7 or the apparatus 620 shown in Figures 8 and 9 and described herein may include a seal generally similar to the seal 240 or the seal 740 but configured to clean an optical surface on the inside of a receptacle or an inner optical surface.

[0118] In some embodiments, an apparatus that functions generally similarly to the apparatus 120 shown in Figures 1-7 or the apparatus 620 shown in Figures 8 and 9 and may include a seal generally similar to the seal 240 or the seal 740 and including an applicator portion, wiper portion and first barrier portion generally similar to the applicator portion 250, wiper portion 242, and first barrier portion 440 but wherein a second barrier portion coupled between the wiper portion and the applicator portion extends opposed to or below the first barrier portion 440, such that a window is defined on the optical surface, the window fully enclosed or surrounded by the seal 240. In various embodiments, the wiper portion may be disposed adjacent to the window extending at least 120 degrees about the axis of symmetry on the optical surface, the window configured to facilitate light transmission through the window to or from an optical device. In such embodiments, the window may extend at least 270 degrees about the axis of symmetry on the optical surface.

[0119] Referring to Figures 10 and 11 , there is shown an isometric view and a side view of an optical surface 1210 of a receptacle and a seal 1240 that may be used in an apparatus generally similar to the apparatus 120 shown in Figures 1-7 and described herein. Referring to Figure 10, in various embodiments, the seal 1240 may be generally similar to the seal 240 shown in Figures 1-7 except that the seal 1240 includes a first barrier portion 1440 that extends non-orthogonally to an axis of symmetry 1212 along the optical surface 1210 and thus does not lie in a plane normal to the axis of symmetry 1212. For example, in some embodiments, the first barrier portion 1440 may have a non-zero slope along the optical surface 1210, with a component of the direction of the path of the first barrier portion 1440 non- orthogonal to the axis of symmetry 1212. In some embodiments, the first barrier portion 1440 may move upwards or towards a housing of the apparatus as the first barrier portion 1440 proceeds along the optical surface 1210 from an applicator portion 1250 to a wiper portion 1242. In various embodiments, this configuration may reduce ingress of contaminants from the environment past the first barrier portion 1440 during relative rotation between the first barrier portion 1440 and the optical surface 1210 by causing contaminants to move away from the first barrier portion 1440 upon relative movement of the optical surface 210 relative to the barrier portion 1440, until the contaminants are eventually removed by the wiper portion 1242 of the seal 1240 or a transition portion of the seal acting as a wiper portion.

[0120] In some embodiments, the first barrier portion 1440 may extend for more than 120 degrees about the axis of symmetry 1212 on the optical surface 1210, the first barrier portion 1440 extending at a barrier angle of between 0.5 and 5 degrees relative to a plane normal to the axis of symmetry 1212. In some embodiments, the barrier angle may be 1 degree. In various embodiments, the barrier portion 1440 may have a constant helical slope along the optical surface 1210. In various embodiments, the first barrier portion 1440 extending for more than 120 degrees at a low non-zero angle or slope between 0.5 and 5 degrees may provide a large field of view for the window 1244 and / or reduce ingress of contaminants past the seal 1240. In some embodiments, the first barrier portion 1440 may extend for more than 270 degrees about the axis of symmetry 1212 on the optical surface 1210. In such embodiments, the field of view for a window 1244 may be enlarged by such a configuration.

[0121] In some embodiments, an apparatus generally similar to the apparatus 120 shown in Figures 1-7 may include a second barrier portion generally similar to the second barrier portion 442 shown in Figure 2 except extending non-orthogonally to an axis of symmetry and thus not lying in a plane normal to the axis of symmetry, generally as described herein having regard to the first barrier portion 1440 shown in Figure 10 and 11.

[0122] Language of degree used herein, such as the terms “approximately,” “about,” “generally,” and “substantially” as used herein, unless defined otherwise, may represent a value, amount, or characteristic close to the stated value, amount, or characteristic that still performs a desired function or achieves a desired result. For example, the terms “approximately”, “about”, “generally,” and “substantially” may refer to an amount that is within less than 10% of, within less than 5% of, within less than 1% of, within less than 0.1% of, or within less than 0.01% of the stated value.

[0123] While specific embodiments of the present disclosure have been described and illustrated, such embodiments should be considered illustrative of the present disclosure only and not as limiting the present disclosure as construed in accordance with the accompanying claims.

Claims

CLAIMS:

1. An apparatus for protecting an optical device during operation, the apparatus comprising: a receptacle configured to receive the optical device, the receptacle including an optical surface, the optical surface being generally rotationally symmetric about an axis of symmetry, wherein at least a portion of the optical surface extends non-orthogonally relative to the axis of symmetry to radially enclose at least a portion of the optical device when the optical device is received in the receptacle; a seal including an engagement edge shaped generally complementary to the optical surface of the receptacle and held in engagement with the optical surface to seal against the optical surface, wherein the seal forms a continuous loop on the receptacle and includes a wiper portion that extends non-orthogonally to the axis of symmetry along the optical surface of the receptacle; and an actuator coupled between the receptacle and the seal, the actuator configured to cause relative rotation about the axis of symmetry between the receptacle and the seal to cause the wiper portion to slide along the optical surface and dislodge contaminants from the optical surface.

2. The apparatus of claim 1 wherein the seal substantially surrounds the axis of symmetry.

3. The apparatus of claim 2 wherein the seal forms a continuous loop around the axis of symmetry.

4. The apparatus of any one of claims 1 to 3 wherein the wiper portion is disposed adjacent to a window extending at least 120 degrees about theaxis of symmetry on the optical surface, the window configured to facilitate light transmission through the window to or from the optical device.

5. The apparatus of claim 4 wherein the window extends at least 270 degrees about the axis of symmetry on the optical surface.

6. The apparatus of any one of claims 1 to 5 wherein the wiper portion of the seal extends at an angle of between 45 degrees and 135 degrees relative to a direction of travel of the optical surface or the wiper portion during relative rotation about the axis of symmetry between the receptacle and the seal.

7. The apparatus of claim 6 wherein the wiper portion of the seal extends generally parallel with the axis of symmetry.

8. The apparatus of any one of claims 1 to 7 wherein the wiper portion includes: a wiper base; a wiper optical surface engager extending from the wiper base, the wiper optical surface engager including a wiper edge configured to engage with the optical surface; and a wiper hinge coupled between the wiper optical surface engager and the wiper base, the wiper hinge configured to facilitate rotation of the wiper optical surface engager relative to the wiper base.

9. The apparatus of claim 8 wherein the wiper hinge has a reduced cross sectional thickness compared to at least a portion of the wiper optical surface engager.

10. The apparatus of claim 8 or 9 wherein the wiper edge forms an angle of between 70 degrees and 90 degrees.

11. The apparatus of any one of claims 1 to 10 wherein the seal includes an applicator portion that extends non-orthogonally to the axis of symmetry along the optical surface of the receptacle, the applicator portion configured to slide along the optical surface and facilitate application of an optical layer medium to the optical surface.

12. The apparatus of claim 11 wherein the applicator portion of the seal extends at an angle of between 45 and 135 degrees relative to a direction of travel of the optical surface or the applicator portion during relative rotation about the axis of symmetry between the receptacle and the seal.

13. The apparatus of claim 12 wherein the applicator portion of the seal extends generally parallel with the axis of symmetry.

14. The apparatus of any one of claims 11 to 13 wherein the applicator portion and the wiper portion of the seal have generally the same cross-sectional shape.

15. The apparatus of any one of claims 1 to 14 wherein the seal has a generally constant cross-sectional shape throughout.

16. The apparatus of any one of claims 1 to 15 wherein the optical surface is generally cylindrical.

17. The apparatus of any one of claims 1 to 15 wherein the optical surface is generally spherical dome shaped.

18. The apparatus of any one of claims 1 to 17 wherein the optical surface includes an outer optical surface.

19. The apparatus of any one of claims 1 to 18 comprising a housing coupled between the seal and the actuator and holding the optical device, the housing configured to enclose the optical device in the receptacle when the optical device is received in the receptacle.

20. The apparatus of any one of claims 1 to 19 wherein the seal is a continuous loop of flexible material.

21. The apparatus of claim 20 wherein the seal has a constant cross-sectional shape along the continuous loop.

22. The apparatus of any one of claims 1 to 21 wherein the seal follows a smooth curved path along the optical surface.

23. The apparatus of any one of claims 1 to 22 wherein the seal includes a barrier portion that extends non-orthogonally to the axis of symmetry along the optical surface of the receptacle, the barrier portion extending for more than 120 degrees about the axis of symmetry on the optical surface and extending at a barrier angle of between 0.5 and 5 degrees relative to a plane normal to the axis of symmetry.

24. The apparatus of claim 23 wherein the barrier portion extends for more than 270 degrees about the axis of symmetry on the optical surface.

25. The apparatus of any one of claims 1 to 24 comprising the optical device.

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