Very low profile anti collision light

A light configured to be coupled to a surface, where the light includes a light source configured to emit light in three dimensions and a lens configured to direct a majority of the light emitted by the light source outwardly from the light source in directions along the surface. The light may be an anti collision light for an aircraft.

FIELD

The present teachings relate to the field of aircraft safety systems and, more particularly, to aircraft anti collision lighting systems including one or more anti collision lights.

BACKGROUND

United States Federal Aviation Administration regulations require anti collision lighting on commercial and other aircraft. For example, C.F.R. §23.1401 specifies the requirement for anti collision lighting. Further, the anti collision lighting must meet specific criteria with regard to, for example, field of coverage, flashing characteristics, color, light intensity, and minimum effective intensities.

Anti collision lighting typically includes a light source or lamp, such as an incandescent or halogen bulb, and a lens that covers and protects the light source. The light source and lens are attached to the exterior surface of the aircraft, for example on an upper and/or or lower surface of a fuselage, wing, vertical stabilizer, and/or horizontal stabilizer of the aircraft.

While anti collision lighting is an essential safety component, the lighting can adversely impact operational characteristics of an aircraft. For example, the bulb that provides the light source and the lens that protects the bulb must extend from the aircraft exterior surface by a distance to be sufficiently visible from a low angle relative to the aircraft. Some lenses in anti collision lighting systems can extend at least 3.0 inches, and in some designs up to 6.0 inches, away from the aircraft exterior surface. This protrusion of the lens away from the aircraft surface can result in the lens extending into the airstream during operation of the aircraft, thereby creating significant aerodynamic drag increasing fuel consumption and carbon dioxide emissions, etc. For example, the drag created by some anti collision lighting can be equivalent to carrying an additional 250 pounds of payload.

Further, the lighting systems add additional weight to the aircraft, which also increases fuel consumption. Some anti collision lighting systems can add an additional 3 to 4 pounds of weight to the aircraft.

Moreover, because the lens that protects the bulb extends away from the aircraft surface by up to 6.0 inches, the lens must be manufactured from a durable material that resists abrasion and other damage from particles in the airstream such as dust, rain, ice, etc. Conventional lenses may be manufactured from relatively expensive materials such as glass and high-density polymers with expensive coatings to protect the lens from abrasion.

An anti collision lighting system having a decreased impact on aerodynamic drag and fuel consumption, reduced power draw from the aircraft electrical system, reduced weight, and a lower cost would be desirable.

SUMMARY

An embodiment can include a light configured to be coupled to a surface, the light including a light source configured to emit light in three dimensions and a lens configured to direct a majority of the light emitted by the light source outwardly from the light source in directions along the surface. The directions the majority of the light is directed along the surface can include all the directions along the surface. The light can define an area on the surface wherein the light source is positioned within the area and the directions include directions radially outward from the light source along the surface.

The light can provide an anti collision light for an aircraft, where the light further includes a plurality of light emitting diodes (LEDs), wherein each LED includes a light emitting surface configured to emit light and a width across the front surface, a lens including a first surface configured to cover the plurality of LEDs and an exterior surface of the aircraft, a second surface opposite the first surface, and an edge having a height that extends between, and intersects, the first surface and the second surface, wherein the lens is configured to focus the majority of the light emitted from the plurality of LEDs outward through the edge. In an embodiment, the height of the edge is equal to 7.0 times a width of one LED, or less. In another embodiment, the anti collision light is configured to protrude from the exterior surface of the aircraft by a distance equal to 7.0 times a width of one LED, or less.

The lens can further include a first surface, a second surface opposite the first surface, and a third surface at a level interposed between a level of the first surface and a level of the second surface. The third surface can define at least a portion of a recess in the lens to receive the plurality of LEDs.

The light source may include a plurality of light emitting diodes (LEDs) and the light may further include a continuous polymer carrier that physically connects the plurality of LEDs into a light strip.

The lens may further include a first surface, a second surface opposite the first surface, a third surface, and a recess defined, at least in part, by the third surface. The first surface of the lens may have a first plane, the second surface of the lens may have a second plane, and the third surface of the lens may have a third plane at a level that is interposed between the first plane and the second plane. The first plane, the second plane, and the third plane may be substantially parallel, each with the other, and the light strip may be received within the recess.

The light can further include a base, the base having a mounting surface, wherein the light source is positioned between the mounting surface and the lens.

The light can further include a plurality of light emitting diodes (LEDs) that provide the light source, a continuous polymer carrier that physically connects the LEDs into a light strip, and a circuit substrate electrically coupled to the light strip, wherein the circuit substrate is positioned on a surface of the base within a periphery established by the light strip. The base can further include a post configured to extend through an opening in the exterior surface of the aircraft, and a channel through the post. The circuit substrate can include an electrical interconnect electrically coupled with the circuit substrate, and the electrical interconnect extends through the channel in the post.

The light may include at least one fastener that attaches the lens to the base extends through a first opening through the lens and a second opening through the base. The at least one fastener can be configured to attach the lens and the base to an aircraft surface, and extend through a third opening through the aircraft surface.

The lens may include a first surface, a second surface opposite the first surface, and an edge that intersects the first surface and the second surface, and the edge intersects the first surface of the lens at an angle of 90°, or at an angle of from 30° to 60°.

The light can further include a reflective coating on a surface of the lens that reflects light emitted by the light source back into the lens.

An aircraft can include an anti collision lighting system, the anti collision lighting system having an anti collision light with a lens. The lens can include an upper surface, a lower surface, an edge that extends between, and intersects, the upper surface and the lower surface, and an intermediate surface at a level between the lower surface and the upper surface, the intermediate surface defining at least a portion of a recess. The anti collision lighting system can further include a light strip having a plurality of light sources positioned within the recess, a pedestal including a raised mounting surface having a sidewall, wherein the plurality of light sources are mounted to the sidewall and the raised mounting surface is positioned within the recess, a flange that intersects the sidewall, and an aircraft surface, wherein the anti collision light is attached to the aircraft surface. The aircraft can further include at least one fastener that attaches the lens to the pedestal and to the aircraft surface, and extends through a first opening through the lens, a second opening through the flange, and a third opening in the aircraft surface.

The aircraft can further include an exterior surface, and the anti collision light can be configured to protrude from the exterior surface of the aircraft by a distance of 0.5 inches or less.

The aircraft can further include an exterior surface, where the anti collision light is configured to protrude from the exterior surface of the aircraft by a distance of 0.185 inches or less.

A method of directing light can include providing a plurality of light emitting diodes (LEDs), wherein each LED includes a front surface configured to emit light and a width across the front surface, providing a lens having a lower surface configured to overlie the plurality of LEDs, an upper surface opposite the lower surface, and an edge having a height that extends between, and intersects, the lower surface and the upper surface, wherein the height of the edge is equal to 7.0 times the width of one LED, or less. The method can further include encasing the plurality of LEDs within the lens, wherein the anti collision light is configured to emit the light from the plurality of LEDs, through the lens, and out of the edge of the lens.

The method may further include attaching the anti collision light to an exterior surface of an aircraft wherein, subsequent to the attaching, the anti collision light protrudes from the exterior surface of the aircraft by a distance equal to 7.0 times the width of one LED, or less. The method may further include mounting the plurality of LEDs to a sidewall of a raised mounting surface of a pedestal, wherein the sidewall extends from a flange of the pedestal, and attaching the lens to the flange of the pedestal. Further, the pedestal may be attached to the exterior surface of the aircraft using a plurality of fasteners.

An anti collision light for an aircraft can include a lens having a lower surface configured to overlie an exterior surface of the aircraft, an upper surface opposite the lower surface, and an edge that extends between, and intersects, the lower surface and the upper surface, wherein the anti collision light is configured to protrude from the exterior surface of the aircraft by a distance of 0.5 inches or less.

It should be noted that some details of the FIGS. have been simplified and are drawn to facilitate understanding of the present teachings rather than to maintain strict structural accuracy, detail, and scale.

DESCRIPTION

The technology described herein may be used in any system where lighting is desired. Examples include, but are not limited to, aerospace vehicles, military, commercial, or private flight vehicles, reusable spacecraft, lighting systems for military, commercial, or private purposes, and re-entry systems. As used herein, “aircraft” refers to any vehicle capable of flight within an atmosphere, partial vacuum, and/or vacuum.

An embodiment of the present teachings can provide a low profile anti collision lighting system that is visible from both low angles and high angles and has significant advantages compared to some conventional systems. For example, the disclosed lighting system has reduced aerodynamic drag, reduced weight, and a lower power requirement compared to conventional anti collision lighting, and provides a light output within required visibility specifications and regulations. Further, the disclosed low-profile anti collision system can have a lower weight than conventional systems, thereby decreasing fuel consumption and carbon dioxide emissions. Additionally, because the low-profile lighting system includes a low-profile lens that extends away from the aircraft surface by a reduced distance, the lens has a decreased vulnerability to dust and debris, and therefore may be manufactured from a less expensive material than conventional lenses. An arrangement of a light source, such as a plurality of LED's, at least partly enables the low profile design of the anti collision light.

An anti collision lighting system100according to an embodiment of the present teachings is depicted inFIGS. 1-3, whereFIG. 1is an exploded sectional view,FIG. 2is an assembled sectional view, andFIG. 3is a plan view. Various measurements (in inches) are depicted inFIG. 1. The embodiment depicted inFIG. 1generally includes a base or pedestal102, a light strip104, and a lens106. While the teachings are discussed with regard to a lens as a light guide, it will be understood that the present teachings can be applied to any light guide, where the light guide is a structure or technique that is used to direct or redirect light toward a desired direction. It will be further understood that the FIGS. are generalized schematic depictions and that an anti collision lighting system may include other structures that are not depicted for simplicity, while various depicted structures may be removed or modified. The dimensions shown are for descriptive purposes only and may vary to accommodate different platform integration requirements. InFIGS. 1 and 2, the pedestal102and lens106are depicted in cross section, while the light strip104is a perspective depiction.

The pedestal102includes a raised mounting surface108having a sidewall110to which the light strip104is mounted using, for example, an adhesive (not individually depicted for simplicity) such as a liquid adhesive or a double-sided pressure sensitive adhesive. The pedestal102further includes a post112that is inserted into an opening200(FIG. 2) in the aircraft surface202. Additionally, the pedestal102can include a flange114to which the lens106may be mounted using, for example, one or more fasteners204(FIG. 2), such as one or more screws, bolts, pegs, or other fasters, each of which may be countersunk into a hole206in the lens106and/or the flange114and thereby flush mounted with an upper or top surface116of the lens106.

Other fasteners and attachment techniques are contemplated. The flange114may also be used to secure the lens106and pedestal102to the surface202using the fasteners204as depicted inFIG. 2. In another embodiment, the post112of the pedestal102may include threads138that are screwed into, and received by, threads214in the aircraft fuselage202. Other types of connections are contemplated, such as a twist lock notch, etc. The pedestal102may be manufactured from, for example, a lightweight metal such as aluminum, a metal alloy, or a polymer that is sufficiently resilient under expected stresses and capable of performing as a heat sink for the light strip104. The raised mounting surface108, specifically the sidewall110, extends from the flange114, and intersects the upper surface122of the pedestal102.

The light strip104can include a plurality of individual light sources118, for example a plurality of light emitting diodes (LEDs). The light strip104may be fabricated, for example, in a manner similar to conventional flexible LED tape lights known in the art. The light strip104is described in more detail with regard toFIG. 4.

The flange114of the pedestal102includes a lower surface120and the pedestal includes an upper surface122, where the sidewall110is interposed at a level between the lower surface120of the flange114and the upper surface122of the pedestal. The lower surface120of the flange may physically contact the aircraft surface202as depicted inFIG. 2during use. Further, the lower surface120intersects with the post112at a 90° angle, or another angle or angles appropriate for the contours of the surface202. The upper surface122of the pedestal102may include a first recess124A and a second recess124B that receive a circuit substrate406and integrated driver (i.e., drive) electronics408of the light strip104as described below with reference toFIG. 5. The first recess124A may be continuous with the second recess124B. The pedestal102further includes a channel126through the post112and opens at the upper surface122, for example for routing power and ground to the light strip104from a power supply within the aircraft.

The lens106can include a lower or bottom surface128, an upper or top surface130that is opposite the lower surface128, a first intermediate surface132at a first level between the lower surface128and the upper surface130, and a second intermediate surface134at a second level between the lower surface128and the upper surface130, where the second level is further between the first intermediate surface132and the upper surface130. In this embodiment, the lower surface128has a first plane, the upper surface130has a second plane, the first intermediate surface132has a third plane, and the second intermediate surface134has a fourth plane, where the planes are all generally parallel with each other. The lens106can further include an edge136that intersects the lower surface128and the upper surface130at a right angle, or another angle as described below. WhileFIGS. 1 and 2depict the edge136of the lens106extending beyond an edge137of the flange114, it will be understood that the lens106and pedestal102can be configured such that the edge136of the lens106is vertically aligned or coplanar with, or even recessed from, an edge137of the flange114. In this embodiment, the lens106may have only one intermediate surface134that at least partially forms a recess that receives the light strip104and the raised mounting surface108, including the sidewall110.

The lens106may be manufactured from a lightweight transparent or translucent material such as a polymer. In another embodiment, the lens106may be manufactured from glass. As depicted inFIG. 1, the lens may have a very low maximum thickness or height compared to conventional anti collision lights, and may therefore protrude or extend very slightly from the aircraft surface and have a very low profile. As depicted inFIGS. 1 and 2, the lens106may have a maximum thickness or height of 0.185 inches or less and extend away from the aircraft surface by this distance depending, for example, on a height of the light strip104. Thus, in this embodiment, the anti collision lighting100, and more particularly the lens106and light source104, are configured to extend or protrude from the surface202of the aircraft by no more than 0.185 inches. In another embodiment, the lens106may have a thickness of from about 0.125 inches to about 0.375 inches, or 0.5 inches or less, or 0.375 inches or less, and thus protrude or extend from the aircraft surface by a distance equal to the maximum thickness of the lens. In another embodiment, the lens106and the lower surface120of the pedestal102may optionally rest on a synthetic pad203such as a polymer pad that functions as a pad or seal, in which case the lens106will be configured to extend or protrude from the surface202of the aircraft by no more than 0.5 inches, or no more than 0.375 inches, or no more than 0.185 inches, or from about 0.185 inches to about 0.5 inches. In other embodiments, the synthetic pad203is omitted. As described above, conventional anti collision light may protrude 3.0 inches or more, for example up to 6.0 inches, from the aircraft surface.

In another embodiment, each LED118can include a front, light emitting surface configured to emit light in three dimensions and a back surface attached to or coupled with, for example, the sidewall110of the pedestal102. Alternatively, the LED118can be attached to, or coupled with, a different feature of the pedestal102. Each LED118may further include a width that is measured across the front surface. In an embodiment, the edge136of the lens106may have a height that is equal to about 7.0 times the width of one LED118, or less. In another embodiment, the edge136may have a height that is equal to about 5.0 times the width of one LED118, or less. In another embodiment, the edge136may have a height that is equal to about 3.0 times the width of one LED118, or less, or about 2.0 times, or less, or about 1.5 times, or less. In an embodiment, the lens106can be configured to direct a majority of the light emitted by the light source (e.g., LEDs118) outwardly from the light source118in directions along the surface to which it is attached. In other words, the lens106directs the majority of the hemispherically directed light emitted by the LEDs118in a substantially planar direction, the substantially planar direction established, or generally bounded, by the upper and lower surfaces of the lens106, toward the edge136of the lens106. The substantially planar direction of the lens106directed light transmits the emitted light out the edge136and along the surface to which the lighting system100is attached. In an embodiment, the lens106directs a majority of the light emitted by the LEDs in all directions (i.e., through 360°) along the surface to which the light is attached, such that light is emitted around the entirety of the edge136of the lens106. In an embodiment, the lens106can selectively direct the light emitted by the LEDs in less than all directions, e.g. less than 360° all around the edge136, such as 90°, 180°, 270°, intermittent angle ranges around the edge136such as every other 45°, and the like. In an embodiment, the light100defines an area on the surface to which the light100is attached, the light100is positioned within the area, and the lens106directs the light emitted by the LED118radially outward from the light source118along the surface to which it is attached. In an embodiment, the lens106can redirect light emitted from the LEDs118such that about 70% or more, or 80% or more, or 90% or more, or about 95% or more, or about 98% or more, of the light emitted from the plurality of LEDs118can be emitted through the edge136of the lens106. Thus, while the light may be emitted from each LED118of the plurality of LEDs118in three dimensions, the lens136redirects the emitted light such that it is emitted from the edge136of the lens106.

FIG. 2depicts theFIG. 1assembly attached to the aircraft surface202, andFIG. 3is a plan view of theFIG. 2structure. In an embodiment, the light strip104and the top surface122of the pedestal102may be positioned into a first recess defined, at least in part, by the second intermediate surface134as depicted inFIG. 2. The flange114of the pedestal102may be positioned into a second recess defined, at least in part, by the first intermediate surface132. Further, the fastener204may be countersunk into the hole206in the lens106, through a hole208in the flange114of the pedestal102, and through or into a hole210in the surface202. The surface202may be an exterior surface of the aircraft fuselage, wing, vertical stabilizer, horizontal stabilizer, or another exterior surface of the aircraft.

In another embodiment, the lens106may be bonded to the flange114and the light strip104using a transparent adhesive205(FIG. 2), where the plurality of LEDs118are positioned between the mounting surface110and the lens106. Adhesive205may be, for example, a transparent silicone or another transparent adhesive. If the adhesive205is not used, an air gap may remain between the LEDs118of the light strip104and surface133(FIG. 1) of the lens106. This air gap can result in more light being reflected away from the surface133of the lens106, and an overall decrease in light output from the anti collision lighting system100. Because the adhesive205has a density or optical index that is closer to the density or optical index of the lens106, less light is reflected off of surface133resulting in an overall increase in light output at lens edge136. Thus, the adhesive205effectively functions as a part of the lens, may provide a light that has no air gap between the light source118and the lens, and may have a beneficial effect on the light output of the anti collision light100. Embodiments including both the adhesive205and the one or more fasteners204are contemplated.

FIG. 4is a plan view of the light strip104prior to assembly to the sidewall110of the pedestal102. The light strip104of this embodiment includes a plurality of discrete light sources118such as a plurality of LEDs118. The plurality of LEDs118may be physically connected together with a carrier400such as a plastic, polyimide, Kapton®, or other flexible polymer carrier. The plurality of LEDs118may further be electrically connected together, in series or parallel, through a ground interconnect402that is electrically coupled to a ground connection, and to a power interconnect404that is electrically coupled to a power connection. The light strip104ofFIG. 4depicts 36 LEDs118, but may include any number of light sources118, such as from 36 to 72 LEDs, fewer than 36 or more than 72 LEDs.

The LEDs118may be, for example, micro-sized LEDs having a surface area of 2 mm2or less and a thickness of 1 mm or less. In an embodiment, the LEDs118may not be covered by an integral lens as is typically found with LEDs, so that the light output from the LEDs is more omnidirectional than unidirectional, as would be the case if each LED included a separate domed or integral lens. Each LED may have a high power density, with a luminous flux in the range of from about 40 lumens to about 80 lumens, or from about 50 lumens to about 70 lumens, or about 60 lumens. Each LED may have a luminous efficacy in the range of from about 40 to about 55 lumens/watt, although other lumens and efficacies are contemplated.

The light strip104can further include a circuit substrate406. The circuit substrate406may include a carrier such as a plastic, polyimide, or other flexible polymer carrier, which may be formed as a continuous layer along with the carrier400. In another embodiment, the circuit substrate406may be a printed circuit board that is electrically coupled with the LEDs118through the interconnects402,404. In contrast to conventional anti collision lights, the circuit substrate406can include integrated driver electronics408such as one or more power converters, timers, and/or other control circuitry and integrated power converter/supply circuitry to operate the light sources118. The circuit substrate406is electrically coupled with the aircraft power and/or other aircraft electronics410through an electrical interconnect411. The power supply and/or other aircraft electronics410may be part of the aircraft electrical system. In another embodiment, the anti collision lighting100may include a separate power supply and/or other electronics. The interconnect411may include a wired and/or a wireless connection. In an embodiment, the light sources118may be physically attached to a first carrier portion412and the driver electronics408may be attached to a second carrier portion formed by the carrier substrate406. The first carrier portion412and the second carrier portion406may be physically connected together by a third carrier portion414. A portion of the power interconnect404and ground interconnect402may be formed on the third carrier portion414. The dimensions depicted (in inches) inFIG. 4are not intended to be at all limiting, and will vary depending on, for example, the circumference of the sidewall110of the pedestal102. The first carrier portion412, second carrier portion406, and third carrier portion414may be a single piece of carrier material, such as a single piece of Kapton®.

FIG. 5is a plan view depicting the pedestal102. During assembly of the anti collision lighting system100, the circuit substrate (e.g., the second carrier portion)406and driver electronics408(FIG. 4) of the light strip104are mounted into the first recess124A. The third carrier portion414is routed through the second recess124B, and the first carrier portion412is mounted to the sidewall110. The circuit substrate406is thereby recessed within the top surface122of the pedestal102, such that an upper surface of the circuit substrate406does not extend above an uppermost portion500of the top surface122of the pedestal102. The circuit substrate406may be secured to the pedestal102with an adhesive or fasteners (not individually depicted for simplicity), or may be held in place by the lens106. After assembly, the first intermediate surface132of the lens106may physically contact and/or overlie the flange114of the pedestal102, and the second intermediate surface134of the lens106physically contacts and/or overlies the uppermost portion500of the pedestal102and the circuit substrate406of the light strip104. The electrical interconnect411may be routed from the bottom or side of the circuit substrate406through an opening502in the post112of the pedestal102, and connects to aircraft electronics. An interior lip504of the pedestal102may be routed through a hole (not depicted for simplicity) in the center of the circuit substrate406. In another embodiment, the circuit substrate406does not include a hole in the center, which provides more space for electronic components. In this embodiment, the electrical interconnect411connects to circuitry routed to the bottom of the circuit substrate406, and the electrical interconnect411extends from the bottom surface of the circuit substrate406and through the opening502in the post112of the pedestal102. In another embodiment, the electrical interconnect411may connect to circuitry at the top of the circuit substrate406, and routed around an edge of the circuit substrate406and through the opening502in the post112of the pedestal102. The circuit substrate406ofFIG. 4may be positioned within the first recess124A of the pedestal102ofFIG. 5on a surface of the base or pedestal102which is within a periphery established by the light strip that is mounted to sidewall110. Other electrical connection routing is contemplated.

Various modification to the embodiments depicted and described above will become apparent from the disclosure herein. For example, whileFIG. 3depicts a lens106that is round, other lens shapes are contemplated.FIG. 6is a plan view depicting a lens600having an irregular ellipsoid shape that provides an aerodynamic shape and may have reduced drag compared to the round lens106ofFIG. 3. In this embodiment, the front of the aircraft would be oriented toward the left side ofFIG. 6. as depicted. The lens600may be mounted, for example, to a pedestal that is analogous to pedestal102as depicted inFIGS. 1, 2, and 5. The positioning of countersunk holes602may be designed to prevent improper orientation of the lens.

FIG. 7is a plan view depicting a lens700having an ellipsoid shape. This lens700may be less expensive to manufacture and install than the lens600ofFIG. 6, for example because it has a more regular shape and regularly spaced countersunk holes702, and the lens may be installed correctly in either of two orientations.

FIG. 8is a plan view analogous to the plan view ofFIG. 5, where the pedestal800includes recesses800A-800E. In this embodiment, a light strip900(FIG. 9) would include an array of four light strip segments902A-902D, where each light strip segment may be individually addressed. While theFIG. 8structure is adapted for four light strip segments902A-902D, it will be understood that the anti collision light can be designed for any number of recesses800and light strip segments902. The light strip900can include four different carrier portions904A-904D that are analogous to third carrier portions414(FIG. 4). Recess800A can receive a circuit substrate906, while recesses800B-800E can receive carrier portions904A-904D, where each carrier portion includes power and ground (not individually depicted for simplicity) to selectively power the associated light strip segment. The light strip segments902A-902D can be wrapped around the sidewall110of the pedestal800. In an embodiment, the four individually addressable light strip segments902A-902D can be activated and deactivated in turn to, for example, create a rotating beacon effect.

As discussed above, referring back toFIGS. 1-3, the lens106includes the lower surface128. The lower surface128may physically contact a surface212of the aircraft surface202. In another embodiment, a material such as a polymer may be interposed between the lens106and the surface212of the aircraft. The lens106further includes an edge136that intersects the lower surface128at an angle. In this embodiment, the surface212is an exterior surface202of the aircraft. As depicted inFIG. 1, the edge136intersects the lower surface128of the lens at a right angle. In this embodiment, majority of the light that is emitted from the plurality of LEDs118will travel through the lens106and exit the edge136of the lens106at a generally horizontal angle relative to the orientation of the aircraft (assuming the lens is on a horizontal surface of the aircraft), or generally normal/perpendicular, or 90° to the top surface116of the lens106. In this embodiment, the light emitted from the anti collision light100may exit the edge136at generally lower angles, and will therefore be most visible from a low angle relative to the upper surface116of the lens106. The amount of visible light may decrease with an increasing viewing angle that is above the upper surface116of the anti collision light100. Another embodiment of a lens1000including a lower surface128that physically contacts the exterior surface212(FIG. 2) of the aircraft is depicted inFIG. 10. In this embodiment, an edge1002of the lens intersects the lower surface128at an acute angle, for example at an angle of from about 30° to about 60°, or another angle. In this embodiment, the light that is emitted from the plurality of LEDs118will travel through the lens1000and exit the edge1002of the lens1000at a generally non-horizontal angle relative to the orientation of the aircraft (assuming the lens is on a horizontal surface of the aircraft), or non-perpendicular to the top surface116of the lens106. In this embodiment, the light emitted from the anti collision light100may exit the edge136at a lower angle than the embodiment of the lens106ofFIG. 1, for example, due to optical refraction as the light transits the interface between the lens and the atmosphere. The acute angle of the edge1002may expose the lower surface of the lens128to view from above, however, which may increase the amount of light viewable from elevated angles. The light that exits the edge1002of the lens1000may be most visible from a higher viewing angle relative to the upper surface116of the lens1002compared to the lens106ofFIG. 1. The amount of visible light may increase with an increasing viewing angle that is above the upper surface116of the anti collision light1000. In another similar embodiment, the edge1002may have a curved profile rather than the straight, angled profile depicted inFIG. 10.

WhileFIG. 1depicts surface136intersecting surface116at a 90° angle, andFIG. 10depicts surface1002intersecting surface116at an angle of greater than 90°, surface1002may also intersect surface116at an angle of less than 90° such that the lens1000has an undercut edge.

Additionally, as depicted inFIG. 10, surface116and/or edge1002may include diffractive elements1003, such as one or more grooves, indentations, bumps, angled surfaces, or other surface features, that encircle the perimeter of the lens1000and tailor the light output from the lens106,1000as desired. These diffractive elements1003may help scatter and/or focus the light as it exits the edges136,1002of the lens106,1000. It will be understood that the diffractive elements1003may not be depicted to scale, and may be relatively smaller or larger than those depicted.

Further, to increase the amount of light that exits the edges136,1002of the lenses106,1000, the top surface116and/or bottom surface128and/or intermediate surface132of the lenses106,1000may be coated with a reflective coating1004, such as a thin, metal coating. This reflective coating can assist in channeling light that is output from the light strip104to the edges136,1002of the lenses106,1000, and reduces or prevents light from exiting from the surfaces116,128,132. In an embodiment, light output from the edge116,1002of the lens106,1000is maximized, and light output from surfaces116,128,132is minimized, where possible. Thus the hemispherically directed light emitted by the LEDs is directed radially outward toward the lens edge136,1002, as well as toward the upper surface116, lower surface128, and intermediate surface132of the lens1000. The lens1000inherently reflects light inwardly when emitted toward the inner surfaces of the lens at some angle less than perpendicular, or less than 90 degrees. Light that is emitted from the LEDs in a perpendicular direction toward the lens inner surfaces will generally pass through and out of the lens material. The coating1004may thus reduce or prevent the emission of light out of the upper surface116and/or the lower surface128and/or the intermediate surface132of the lens1000. Preventing the emission of light out of the surfaces116,128,132of the lens1000prevents the “wasting” of light that could otherwise be redirected out the radial sides of the lens to provide a higher light intensity. The coating1004may be a monolayer or a few atoms or molecules thick, or another sufficient thickness. The coating1004can be selectively applied, or not applied, to the surfaces116,128,132of the lens adjacent the edges136,1002to selectively direct a portion of the emitted light through the surfaces116,128,132. For example, the top surface116can omit the coating on the last 0.25 inches adjacent the edge136to allow additional light to be directed through the top surface116, thus a majority of the emitted light is directed through the edge136and a portion of the emitted light is directed through the top surface116.

In an embodiment, an anti-collision light such as that depicted inFIG. 1, including the pedestal102, light strip104, and lens106, may have a weight of from about 10 ounces (oz.) to about 15 oz., or from about 11 oz. to about 13 oz., or less than about 13 oz. This is in contrast to some conventional anti collision lights for commercial and military aircraft, which may weigh 3 to 4 pounds. Decreasing the weight of the anti collision light decreases aircraft fuel use and aircraft operation costs.

In various embodiments, the lens106,600,700,1000may be manufactured from a single piece of material, for example using a molding process. After forming the lens, a coating such as coating1004may be applied to the lens.

A light according to one or more embodiments herein can include a light source configured to emit light in three dimensions, and a lens configured to direct a majority of the light emitted by the light source outwardly from the light source in directions along a surface to which the light is attached. The directions the majority of the light is directed along the surface to which it is attached can include all the directions along the surface. In an embodiment, the light defines an area on the surface, the light source is positioned within the area, and the directions include directions radially outward from the light source along the surface.

FIG. 11depicts an aircraft1100that includes an anti collision lighting system having one or more anti collision lights1102attached to an exterior surface of the aircraft1100. The one or more anti collision lights1102may be attached to an exterior surface of the aircraft1100, for example, to the fuselage1104, wings1106, vertical stabilizer1108, horizontal stabilizer1110, and/or another exterior surface of the aircraft1100. The one or more anti collision lights1102may be attached to the aircraft in a horizontal position, a vertical position, or a position between horizontal and vertical.

Terms of relative position as used in this application are defined based on a plane parallel to the conventional plane or working surface of a workpiece, regardless of the orientation of the workpiece. The term “horizontal” or “lateral” as used in this application is defined as a plane parallel to the conventional plane or working surface of a workpiece, regardless of the orientation of the workpiece. The term “vertical” refers to a direction perpendicular to the horizontal. Terms such as “on,” “side” (as in “sidewall”), “higher,” “lower,” “over,” “top,” and “under” are defined with respect to the conventional plane or working surface being on the top surface of the workpiece, regardless of the orientation of the workpiece.