Patent Description:
The invention of this application relates to airport runway lighting. More particularly, the invention relates to a new infrared (IR) source used for runway lights and the like.

The present disclosure relates to approach lighting used in an airport runway, and more specifically, to an energy saving semiconductor light source used for a runway approach light.

The invention of this application relates to an IR source for runway lighting. <CIT>discloses an Airport Runway Approach Lighting Apparatus, <CIT> discloses a Covert Runway Lighting Apparatus and Method, US Patent Publication No. <CIT> discloses an Infrared LED Apparatus And Surface Heater, US Patent Publication No.<CIT> discloses a Solid-State Lighting Apparatus for Navigational Aids, <CIT> discloses a Lighting Apparatus For Navigational Aids, <CIT>discloses a System For Providing Thermal Energy Radiation Detectable By A Thermal Imaging Unit, <CIT> discloses a Lighting Unit for Lighting Airfields, <CIT> discloses a LED Flasher, <CIT> discloses a Blister Lights Used for Signaling and/or Marking Purposes, <CIT> discloses a Unidirectional Lighting Device For Illuminating Objects and/or For Marking Lanes, Preferably In The Airport Area, <CIT> discloses a Flush-Mounted Flashing Light, US Patent Publication No. <CIT> discloses an Airfield Lighting with LED, <CIT> discloses an Airfield Lighting System, <CIT> discloses an Elevated Airfield Runway and Taxiway Edge-Lights Utilizing Light Emitting Diodes, US Patent Publication No. <CIT> discloses a Glide-Angle Light for Approach Guidance of Aircraft, US Patent Publication No. <CIT> discloses an Elevated Airfield LED Lighting Device, <CIT> discloses a LED Current Regulation Circuit For Aircraft Lighting System, <CIT> discloses a LED Elevated Light Fixture and Method and <CIT> discloses a Light-Emitting Diode Runway End Identifier Light System and is incorporated by reference for showing the same and forms part of the specification of this application. Also reference is made to the article titled "<NPL>.

Airport runway approach lights are used to assist aircrafts in landing on a runway. Prior art runway approach lights include a thermal source such as an incandescent bulb and a halogen lamp. The thermal source emits infrared spectral components in addition to components of a visible light spectrum. When weather conditions are favorable and visibility is good, a pilot during landing uses the components of the visible spectrum with naked eyes while viewing the runway approach lights. However, when the weather conditions are unfavorable or the visibility is bad, a pilot uses an infrared (IR) camera or an enhanced flight vision system (EFVS) equipped in the cockpit to detect infrared rays emitted from the thermal source for safe landing.

The power consumption of a thermal source used for runway approach light is very large (around <NUM> Watts to <NUM> Watts). Therefore, the thermal source is extremely inefficient because the quantum efficiency to convert energy from an input electrical power to an optical power is very low, and the beam shaping mechanism to convert a generated beam pattern to a required beam pattern is difficult resulting in a high coupling loss.

As a result, a need for an approach light with an energy efficient light emitting diode (LED) light source has been raised recently. However, an energy-efficient LED (e.g., a steady burning white light LED and a threshold green light LED) has, in a practical situation, only a visible spectrum and its almost no infrared wavelengths. As such, an LED light source is not appropriate as a runway approach light for a next generation airport system because it cannot be safely used during severe or low visibility weather conditions.

To solve this issue, attempts have been made to find an efficient infrared (IR) light source to be used in an airport runway approach light. However, there is still a need for an efficient IR source of sufficient intensity for runway lights.

The invention of this application relates to airport runway lighting. More particularly, the invention relates to a new infrared (IR) source used for runway lights and the like. In this respect, the present invention relates to an approach light used in an airport runway, and more specifically, to an approach light that includes an energy saving semiconductor IR light source used for a runway approach light as defined in appended claim <NUM>.

According to one aspect of the present invention, provided is an approach light that includes an IR source for runway lighting that utilizes a new IR Source.

In greater detail, the present invention relates to an approach light that includes an IR Source that includes a silicon nitride IR source. It has been found that a silicon nitride IR Source produces both the infrared intensity needed for runway applications and produces the needed infrared focal point for use with a parabolic reflector to direct the infrared outwardly in a beam shape that is needed in runway applications. While materials like silicon carbide have been used to produce infrared radiation in the past, Applicant has found that silicon carbide IR sources do not work effectively for runway applications. In this respect, silicon carbide IR sources have been used in laboratories for many years. However, while silicon carbide IR sources work well in laboratory environments, Applicant has found that they do not work well for runway applications. Silicon carbide sources do not produce the needed infrared intensity to transmit infrared the distances needed for runway applications. In addition, silicon carbide IR sources do not have the needed beam concentration for use with parabolic reflectors wherein much of the infrared output is not utilized since the infrared produced is spaced from the focal point of the parabolic reflector. Moreover, increasing the size of the silicon carbide IR source to produce the needed infrared output, causes even more of the infrared radiation to be produced away from the focal point of the parabolic reflector. Yet further, the electrical properties, and therefore their optical ones also, for silicon carbide IR sources do not remain constant over time when they are operated for long periods. The properties of silicon carbide sources tend to drift substantially, which also prevent effective use in runway applications and produce more efficiency loses. Accordingly, there are efficiency losses when silicon carbide IR sources are used and when they are used with the types of parabolic reflectors needed for runway applications. By using silicon nitride, infrared intensity is substantially increased in both the level of infrared and the range of the wavelength. Moreover, the infrared can be produced in a tighter or more compact infrared focal point wherein it has been found to work extremely well with parabolic reflectors to broadcast the infrared a much greater distance with lower power consumption. Moreover, silicon nitride sources produce an infrared source that remains constant over time with minimal drift.

According to yet further aspects of the present invention, the IR source is configured to work within a PAR style lamp wherein the approach light of this application can be merely screwed into existing runway lighting systems. Accordingly, the invention of this application could be used on any available AC voltage socket. This can include, but is not limited to, replacing a certain number of LED lights with the PAR style lights of this application.

According to even yet further aspects of the present invention, the PAR style lights can be modified to further enhance the IR output of the IR source without having to modify the existing runway lighting systems.

It has been found that the invention of this application can utilize existing runway lighting systems and existing AC voltage socket, but which produces wide band infrared radiation with less energy.

According to other aspects of the present invention, the approach light can include both a high efficiency IR source and high efficiency visible light source wherein the approach light can product both IR output and visible light output more efficiently. Moreover, the dual source light can be configured as a PAR style light and can be used to replace even all of the runway lights in a runway lighting system.

According to even yet other aspects of the present invention, the IR source can include a quartz window, which can be the cover over the PAR style light to even further improve the IR output of the light.

According to other aspects of the present invention, the IR source can include one or more filters.

According to certain aspects of the present invention, the filter includes a quartz window.

According to other aspects of the present invention, the filter can include a "high pass" filter that blocks radiation below a certain level. In one set of embodiments, the filter is below about <NUM> microns. In another set of embodiments, it is below about <NUM> microns.

According to even other aspects of the present invention, the IR source can include a "low pass" filter that blocks radiation above a certain level.

According to yet even other aspects of the present invention, the IR source can include a combined filter wherein it can include more than one filter. For example, the filter can include both a "high pass" filter and a "low pass" filter that can, when used in conjunction with an IR source(s), generate a particular range(s) of wavelengths. This can include an IR bandpass filter that allows only the desired range of wavelengths to pass. Essentially, this can act as both a low pass and a high pass filter wherein the filter rejects (attenuates) frequencies outside the desired range.

According to yet further embodiments, the approach light can include one or more selective controls configured to all the IR source and the visible light source to operate independently from one another. As a result, the IR source can operate independently and/or in conjunction with the visual light source depending upon the weather conditions. Moreover, the selective control of the IR source can be used for other purposes, such as to melt ice and snow from the lens of the light when only the visible light source is required, but where snow and ice are impeding the efficiency of the visibility of the light.

These and other objects, aspects, features and advantages of the invention will become apparent to those skilled in the art upon a reading of the Detailed Description of the invention set forth below taken together with the drawings which will be described in the next section.

The invention may take physical form in certain parts and arrangement of parts, a preferred embodiment of which will be described in detail and illustrated in the accompanying drawings which form a part hereof and wherein:.

Referring now to the drawings wherein the showings are for the purpose of illustrating preferred and alternative embodiments of the invention only and not for the purpose of limiting the same, the invention of this application relates to a light <NUM> that can be used as an airport runway light. More particularly, the invention relates to runway light <NUM> that includes a high efficiency infrared (IR) source <NUM> that can be used for runways and the like.

However, while it has been found that the light of this application works particularly well for use on a runway and will therefore be discussed in relation thereto, the invention of this application has broader application wherein its broad and accurately controllable infrared output can be used in a wide range of applications wherein the invention should not be limited to runway applications.

In greater detail, and with reference to a preferred use of the invention of this application, the present invention is used as an approach light used in an airport runway lighting system <NUM>. Runway light <NUM> includes IR source <NUM> that is a high output and energy saving semiconductor IR light source that can be used for runway approach light systems <NUM>.

Parabolic reflector type optical lamps ("PAR") come in various sizes, output beam shapes and have many uses. Parabolic reflector type optical lamps are named according to their outer diameter measured in <NUM>/<NUM> of an inch, e.g., a PAR20 lamp has an output lens diameter of <NUM> x <NUM>/<NUM> inches or <NUM>. 5in; a PAR38 lamp has an outer diameter is <NUM> x <NUM>/8in = <NUM>. 25in; a PAR56 lamp has an outer diameter is <NUM> x <NUM>/8in = <NUM>. 0in (with <NUM> in = <NUM>).

PAR38 and PAR56 lamps are widely used as above the ground lamps on airport runways. Of special interest for the invention of this application are those used in the Approach Lighting Systems that extend out ½ mile or more from the beginning of some airport's main runways and help an incoming pilot properly align the plane and control its vertical angle of decent. To aid some planes, such as those of FedEx, United Parcel, and some non-commercial and private jets, to land in foggy weather, the planes are equipped with Enhanced Flight Vision Systems (EFVS), which have cameras sensitive to infrared light which propagates better through fog than visible light. This allows such planes to "see" through fog, come up close enough to visually make out the beginning of the runway, and even reduce from <NUM> to <NUM> feet the "decision height" at which the landing has to be aborted (with <NUM> ft = <NUM> and <NUM> nautical mile = <NUM>).

At the present time in the US, the Approach Lighting Systems employ incandescent, i.e., heated tungsten filament PAR38s and PAR56s. These emit much more infrared than visible light which makes them highly energy wasteful under most conditions, except for the case of fog, for the relatively few planes equipped with EFVS cameras.

In order to save energy, the US Energy Department has put a stop to the production of many incandescent lamps, requiring instead the use of LED type lamps, which basically only emit visible light. Thus the fact that this makes such lamps effectively invisible in fog to EFVS cameras, (These cameras cost about a million dollars, there are more than a hundred of them currently in use, and the FAA wants to begin using them on passenger planes. ), this is the last hurdle that is holding up the use of LED lights in Approach Lighting Systems.

The invention of this application produces the needed infrared to solve these problems in the industry. The invention of this application can come in many forms.

A first embodiment is light <NUM> that includes infrared (IR) source <NUM> that can be used for runways and the like. In this embodiment, light <NUM>, which includes IR source <NUM>, can be configured to simply screw into Approach Lighting System <NUM> fixtures that could, for example, be mounted side by side with visible LED type PAR lamps. Together, the invention of this application and currently available visible LED type PAR lamps would draw less energy than the incandescent PAR lamp they would replace, emit as least as much visible light and emit substantially more infrared detectible by all types of EFVS cameras.

Referring to <FIG>, shown is a MALSR, or Medium Intensity Approach Lighting System <NUM>. These systems include nine ten foot long bars <NUM>, on each of which there are five incandescent <NUM> to <NUM> watt white light PAR38 lamps <NUM>. Also included are eighteen <NUM> watt white light PAR56 lamps fitted with green filters <NUM>; these form the threshold <NUM>, or beginning, of the runway beyond which the pilot can land. There are <NUM> MALSRs on US runways and many other similar and even larger Approach Lighting Systems on runways throughout the world. Thus, there is a very large need for reduced energy LED type PAR lamps, along with infrared lamps that can be conveniently mounted side-by-side on airports throughout the world.

There is another possible use for the PAR infrared type lamps of this application. The infrared output spectrum of their sources extends over the range <NUM> to <NUM> microns. For security type uses, it is possible to use various types of filters to limit a lamp's emitted spectrum, for example, to wavelengths longer than <NUM> microns, or to wavelengths in the range <NUM> to <NUM> microns.

In greater detail, a typical MALSR system <NUM> uses eighteen green lamps (PAR56) <NUM> along runway threshold <NUM> spaced ten feet apart. In addition, there are nine light bars <NUM> with five white lights (PAR <NUM>) <NUM> separated every two hundred feet and five sequenced flashers <NUM> also separated every two hundred feet over a distance of <NUM>,<NUM> feet from the runway threshold. At the <NUM>,<NUM> feet point <NUM>, there are three light bars (fifteen lamps) for added visual reference for the pilot on final approach. Sequenced flashing lights provide added visual guidance down the runway centerline path. Planned approach visibility is at least <NUM>,<NUM> feet to. <NUM> miles, with a decision-to-land-or-abort altitude of <NUM> feet (with <NUM> ft = <NUM> and <NUM> nautical mile = <NUM>).

Again, the invention of this application can utilizes a PAR type lamp configuration, such as PAR38 and PAR56, that employs an IR Source <NUM>. IR source <NUM> includes a silicon nitride element IR Source instead of tungsten incandescent to produce wide band infrared radiation. Moreover, IR source <NUM> produces virtually no visible light even though it produces high powered and broad spectrum infrared radiation. In this respect, the infrared source <NUM> can produce less than <NUM>% of the visible light than the light that is produced by a traditional PAR style bulb. Moreover, the virtually no visible light can be below <NUM>% of the visible light that is produced by a traditional PAR style bulb. IR source <NUM> will glow red and its peak output of visible light can be less than about <NUM>% that of a PAR38 incandescent bulb.

In greater detail, and with reference to <FIG> showing one set of embodiments, light <NUM> has a PAR configuration that is designed to replace an existing PAR bulb and/or can be any other type of bulb and/or light fixture. Light <NUM> includes a light body <NUM> having a base <NUM> and an enclosure <NUM> that can be a wide range of enclosures without detracting from the invention. Enclosure <NUM> can include cooling fins <NUM> to prevent the overheating of light <NUM>. Light <NUM> further includes one or more output windows <NUM> wherein output window <NUM> can be part of an output window assembly <NUM> that can be fixed relative to enclosure <NUM> by any means known in the art. Base <NUM> can be a traditional PAR style base having a screw thread <NUM>, an electrical screw thread contact <NUM> and an electrical foot contact <NUM>. However, other electrical connections and/or bases could be used without detracting from the invention. Again, light <NUM> can have a wide range of traditional configurations wherein details on the overall bulb structure are not being provided in the interest of brevity in that they are known in the art. Light <NUM> includes an internal light assembly <NUM> that includes IR Source <NUM> that is a high-efficiency IR source that produces significant amounts of infrared radiation and wide band infrared without increased power consumption. Internal light assembly <NUM> can include one or more securing arrangements <NUM> to secure assembly <NUM> relative to enclosure <NUM> and/or output window assembly <NUM>. Securing arrangements <NUM> can include fasteners (not shown in this set of embodiments) to fix assembly <NUM> relative to enclosure <NUM>, or any other fastening arrangement known in the art. Light <NUM> further includes one or more infrared reflectors <NUM> wherein infrared reflector <NUM> can be a wide range of reflectors including a parabolic reflector similar to those configured to work with PAR type lamps (such as PAR38 and PAR56). Reflector(s) <NUM> can be a part of assembly <NUM> and/or form the structure itself. In one set of embodiments, IR source <NUM> employs an element <NUM> assembly that includes a silicon nitride element <NUM> instead of tungsten incandescent to produce wide band infrared radiation. Element assembly <NUM> of IR source <NUM> can have an IR element <NUM> that is mounted in a ceramic base <NUM>. Source <NUM> is electrically connected by way of one or more wires <NUM>.

In one set of embodiments, IR element <NUM> is a flat element formed from Silicon Nitride with a rectangular cross-sectional configuration having both an element thickness and an element width. However, other cross-sectional configurations could be used without detracting from the invention of this application. For example, IR element <NUM> could be cylindrical wherein it has a round cross-sectional configuration with a length and a dimeter. As is shown, the length of IR element <NUM> can be significantly longer than the width and/or the diameter of the element. Below are some dimensions on element <NUM>, which, in the example shown, is flat with a width and a thickness. Ceramic base <NUM> can be a custom bushing design formed from Alumina, Cordierite, and/or Steatite and/or the like. As is shown, base <NUM> is cylindrical in configuration, but this is not required. The resistance of element <NUM> can depend on the desired results.

In one set of embodiments, the resistance of element <NUM> is around <NUM> Ohms when at zero current/room temperature and the resistance of element <NUM> can rise to around <NUM> Ohms at full current. However, these range can vary without detracting from the invention wherein the resistance of element <NUM> can be in the range of <NUM>-<NUM> Ohms when at zero current/room temperature and the resistance of element <NUM> can rise to around <NUM>-<NUM> Ohms at full current. In addition, element <NUM> can have a minimum temperature of about <NUM>,<NUM> degrees Fahrenheit and a maximum temperature of about <NUM>,<NUM> degrees Fahrenheit (<NUM> degrees Celsius and <NUM> degrees Celsius). The steady state current can be in the range of <NUM> Amps to <NUM> Amps at <NUM> Volts.

In one set of embodiments, the dimensions of the element assembly <NUM> are as follows (with <NUM> in = <NUM>):.

In another set of embodiments, the dimensions and parameters of the element assembly <NUM> are as follows:
Silicon nitride element (overall) <NUM>.

In this set of embodiments, the resistance of element <NUM> can be in the range of <NUM>-<NUM> Ohms. The operating voltage can be in the range of <NUM> volts to <NUM> volts. The current draw can be in the range of <NUM> amps to <NUM> amps at <NUM> volts. Operating temperature can be in the range of <NUM> degrees C to <NUM>,<NUM> degrees C wherein the max operating temperature is <NUM>,<NUM> degrees C at <NUM> volts. Also, wherein time to temperature at <NUM> volts is about <NUM> seconds at <NUM> degrees C.

However, as can be appreciated, the dimensions of assembly <NUM>, IR element <NUM> and/or bushing <NUM> can be a wide range of dimensions as well as shapes without detracting from the invention of this application. Moreover, the dimension and/or shape can be adjusted to adjust the overall IR output of the light system and to work with parabolic reflector <NUM> use in light <NUM>. However, the dimensions noted above relate to the embodiments that utilize Silicon Nitride with a specific parabolic lens or reflector wherein the focal point of other type of reflectors could require a differently dimensioned element. Therefore, the dimensions illustrated above are not to be limiting, but are to describe the embodiments shown.

With reference to the embodiments shown, IR source <NUM> has a hot spot <NUM> from which the infrared energy is primarily produced from element <NUM>. Reflector <NUM> is a parabolic reflector that includes a focal point <NUM>. In the embodiment show, hot spot <NUM> is at least closely aligned with focal point <NUM>. In that element <NUM> is formed from a silicon nitride IR Source, hot spot <NUM> has both high intensity and significant beam concentration wherein the high intensity is at least closely aligned with focal point <NUM> wherein much of the infrared output is utilized and broadcasted from light <NUM>. This drastically reduces losses in efficiency, increases output and improves beam shape, which are all highly beneficial for runway applications. Moreover, the electrical properties, and therefore their optical ones also, remain constant over time so that the light can be operated for long periods of time with both high output and high efficiencies. In addition, there is substantially no drift. The embodiment shown has a parabolic reflector with a focal point that is centered in the range of about <NUM> inches to <NUM> inches from its back end <NUM>. The hot spot has a hot spot length <NUM> and is positioned to take advantage of this focal point and can be generally centered relative to the focal point. The hot spot length can be in the range of about <NUM> inches to <NUM> inches in length along the silicon nitride strip that forms element <NUM> (with <NUM> in = <NUM>). With this configuration, the IR output beam is emitted as a maximized well shaped gaussian pattern of full width at half maximum of <NUM> degrees or other desired full width.

According to one set of embodiments, output window <NUM> can be formed by quartz glass window secured in assembly <NUM>. By including a quartz window for output window <NUM>, there is little or no absorption of IR radiation under <NUM> microns and there is substantial radiation in the <NUM> to <NUM> micron range of infrared. Traditional glass envelopes of incandescent PAR lamps completely absorb infrared radiation of wavelengths longer than about <NUM> microns. This is important in that the IR cameras used are much more sensitive at <NUM> microns than at <NUM> microns and the invention of this application produces infrared at this more detectable range to utilize this greater sensitivity, which before now was not possible.

Yet even further, light <NUM> can include one or more filters <NUM>. In one set of embodiments, quartz window <NUM> acts as filter <NUM>. According to other embodiments, filter <NUM> can include a "high pass" filter and/or a "low pass" filter. A high pass filter blocks radiation below a certain level. A low pass filter that blocks radiation above a certain level. In one set of embodiments, the high pass filter blocks radiation below about <NUM>. In another set of embodiments, the high pass filter blocks radiation below about <NUM> microns. In yet other sets of embodiments, the high pass filter blocks radiation below a level that is in the range of <NUM> to <NUM> microns. As for the "low pass" filter, which blocks radiation above a certain level, the low pass filter can be configured to block radiation above about <NUM> microns. In yet other sets of embodiments, the low pass filter blocks radiation above a level that is in the range of <NUM> to <NUM> microns. Moreover, filter <NUM> can include a combined filter wherein it can include more than one filter. For example, filter <NUM> can include both a high pass filter and a low pass filter that can produce IR sources of particular ranges of wavelengths.

This can be used to produce a focused and targeted range of high powered infrared radiation that is much more detectable than prior art IR sources and with less energy consumption.

It has been found that the light of this application produces significant increases in usable infrared output power as compared to a standard incandescent PAR <NUM> style lamp. Therefore, the invention of this application can greatly exceed the infrared output of a standard PAR style lamp with much less power.

Again, the invention of this application can include one or more filters <NUM>. This, combined with the infrared source <NUM> provides both a much broader range of infrared output and a much more controllable output. Moreover, the one or more filters <NUM> can be used to fine tune the broad and powerful infrared product by source <NUM> to create a highly controlled and desirable IR range. Again, this is important in that the IR cameras can be much more sensitive in a particular range of infrared wherein infrared outside this range is merely a waist. For example, infrared cameras used in planes are much more sensitive at <NUM> microns than at <NUM> microns and the invention of this application can provide a wide range of output spectrum to utilize this greater sensitivity. In this respect, infrared source <NUM> of this application produces an infrared output spectrum that extends over the range of about <NUM> to <NUM> microns. Based on the type of use, various types of filters to limit the lamp's emitted spectrum also can be utilized. This can include the high pass filters noted above that block radiation below a certain level. In one set of embodiments, the high pas filter filters IR below about <NUM>. In another set of embodiments, IR is filtered below about <NUM> microns. The invention can also include a "low pass" filter that blocks radiation above a certain level and/or combinations thereof.

In one set of embodiments, infrared source <NUM> produces a broad range of IR and output window <NUM> includes a quartz window that behaves like a low pass filter wherein output window <NUM> will transmit radiation from the visible out to about <NUM> microns wherein the transmission of the light drops to about zero about what is defined as a max filter point (infrared is filtered out above the max filter point). In one set of embodiments, the max filter point is about <NUM> microns as is noted above. However, and as can be appreciated, the max filter point may not be an exact number and/or an exact integer. Therefore, having a max filter point of about <NUM> microns can be a max filter point in the range of <NUM> microns to <NUM> microns. In another set of embodiments, the max filter point is in the range of <NUM> to <NUM> microns. In another set of embodiments, the max filter point is in the range of <NUM> to <NUM> microns. In yet another set of embodiments, the max filter point can be in the range of <NUM> to <NUM> microns. For the one or more high pass filters, they can be defined by a min filter point wherein infrared is filtered out or removed below the min filter point. In one set of embodiments, the min filter point is about <NUM> microns. However, and as can be appreciated, the min filter point also may not be an exact number and/or an exact integer. Therefore, having a min filter point of about <NUM> microns can be a min filter point in the range of <NUM> microns to <NUM> microns. In another set of embodiments, the min filter point is in the range of <NUM> to <NUM> microns. In yet another set of embodiments, the min filter point is in the range of <NUM> to <NUM> microns. In yet another set of embodiments, the min filter point is in the range of <NUM> to <NUM> microns. By including both a high pass filter and a low pass filter, light <NUM> can produce IR radiation in the range of about <NUM> to <NUM> micron, which is a min filter point of about <NUM> microns and a max filter point of about <NUM> microns wherein there is a <NUM> micron band pass result. Similar results, in terms of band pass type systems, in principal can be obtained by combining a low pass filter having a max filter point of about <NUM> microns, followed by a high pass filter having a min filter point of about <NUM> microns, which again resulting in about a <NUM> micron band pass result, but a different <NUM> micron band pass result. This could be used for different applications, such as for covert type applications.

Yet even further, filter(s) <NUM> can include a single filter that transmits a range of wavelengths. This can include an IR bandpass filter that allows only the desired range of wavelengths to pass. Essentially, this can act as both a low pass and a high pass filter wherein the filter rejects (attenuates) frequencies outside the desired range.

With reference to <FIG> and <FIG>, shown is yet another set of embodiments. In greater detail, shown is a light <NUM>, which can also have a PAR like configuration, which includes both an IR source <NUM> and a visible light source <NUM>. Again, IR sources <NUM>, <NUM> of this application produce virtually no visible light, but produce high powered and broad spectrum infrared radiation. In this respect, the infrared sources <NUM>, <NUM> produce less than <NUM>% of the visible light than is produced by a traditional PAR style bulb. Moreover, the virtually no visible light can be below <NUM>% of the visible light that is produced by a traditional PAR style bulb. These IR sources (<NUM>, <NUM>) glow red and its peak output of visible light can be less than about <NUM>% that of a PAR38 incandescent bulb. IR sources <NUM> can be configured that same as IR source <NUM> discussed above wherein the description above with respect to IR source <NUM> can also apply to source <NUM> wherein the description will not be repeated in the interest of brevity.

Accordingly, the invention can further include a visible light source. In the embodiment shown in <FIG> and <FIG>, light source <NUM> includes eight independent light fixtures or assemblies <NUM>; however, more or less than eight light assemblies could be used without detracting from the invention of this application. Light assemblies <NUM> include electrical connection wires <NUM>. As with other embodiments of this application, light <NUM> can be designed to replace existing PAR bulbs and/or any other type of bulb. Moreover, it could be incorporated into its own light fixture (not shown). However, since light <NUM> also produces visible light, it could be used to replace all lights in runway lighting system <NUM>.

Light <NUM> includes a light body <NUM> having a base <NUM>, an enclosure <NUM> and one or more output windows <NUM>. Base <NUM> can be a traditional PAR style base having a screw thread <NUM>, an electrical screw thread contact <NUM> and an electrical foot contact <NUM>. Again, light <NUM> can have a wide range of traditional configurations wherein details on the overall bulb structure are not being provided in the interest of brevity in that they are known in the art. In the embodiments shown, Light <NUM> includes an internal light assembly <NUM> that can support both IR source(s) <NUM> and visible light source(s) <NUM>. Light <NUM> includes IR Source <NUM> that is a high-efficiency IR source that produces significant amounts of infrared radiation and wide band infrared without increased power consumption. Light <NUM> further includes one or more infrared reflectors <NUM> wherein infrared reflector <NUM> can be a wide range of reflectors including those having the same general configuration as those used on PAR type lamps (such as PAR38 and PAR56) and/or to produce a desired beam concentration. However, infrared reflector <NUM> can also be configured for the specific use in connection for the broadcasting of infrared, which is not possible with traditional PAR bulbs. In one set of embodiments, IR source <NUM> employs element assembly <NUM> that can be the same, or similar to element assembly <NUM> referenced above, which can be a silicon nitride element <NUM> instead of tungsten incandescent to produce wide band infrared radiation in increased intensities without additional power consumption. As with the embodiment discussed above, element assembly <NUM> of IR source <NUM> can have a flat IR element <NUM> that can be mounted in ceramic base <NUM>, or the like, which is electrically connected by way of wires <NUM>.

In the embodiment shown, light <NUM> has a plurality of visible light assemblies <NUM> that are independent of IR source <NUM>. However, any number of visible light sources could be utilized in the invention of this application. In greater detail, light <NUM> can include any type of visible light source that can work in combination with IR source <NUM> so that light <NUM> produces both infrared radiation and visible light.

In the embodiment shown, visible light sources <NUM> are LED light sources in that they efficiently produce visible light. Light <NUM> can include a wide range of configurations to allow both infrared radiation and visible light to be projected by light <NUM>. In the embodiment shown, light <NUM> includes a centralized infrared source with the visible light source surrounding the infrared source. In particular, light <NUM> include a light ring <NUM>, which can be part of internal light assembly <NUM>. Ring <NUM> surrounds reflector <NUM> wherein visible light assemblies <NUM> are fixed relative to ring <NUM> and circumferentially surround reflector <NUM>. The group of white light LEDs forming assemblies <NUM> can be configured to match the intensity and beam pattern of the visible light output of a PAR38 incandescent spot lamp and/or that of a PAR56 incandescent spot lamp and/or improve intensity. However, IR source <NUM> has been found to substantially exceed the infrared intensity and the wavelength range of such incandescent spot lamps.

Light <NUM>, when in a PAR38 format, can include a <NUM> inch diameter parabolic reflector <NUM> for the IR beam former. This reflector is surrounded by ring <NUM>, which is an annular light ring. In one embodiment, ring <NUM> has a width <NUM> that is at least. <NUM> inches. In another embodiment, width <NUM> is at least. <NUM> inches. In another set of embodiments, width <NUM> is less than <NUM> inches. In yet another embodiment, width <NUM> is less than <NUM> inches. Ring <NUM> preferably includes a plurality of visible light assemblies <NUM> circumferentially spaced about the ring and about a light axis <NUM>. In one set of embodiments, light assemblies are equally spaced about ring <NUM>. In another set of embodiments, there are at least three visible light assemblies <NUM>. In yet another set of embodiments, there are at least six light assemblies <NUM>. In even yet another set of embodiments, there are eight to ten visible light assemblies <NUM>. Light sources and/or light assemblies can be any visible light producing system. As noted above, it has been found that LED lights sources work well to produce the visible light in view of their efficiency. Light assemblies <NUM> can be a narrow beam lensed <NUM> to <NUM> watt white light LEDs, e.g. CREEEXPL-<NUM>-<NUM> warm white LEDs. The visible light assemblies can be mounted on annular light ring <NUM> along with their electronic drivers and finned heat sinks. Ring <NUM> can be manufactured from a wide range of materials including, but not limited to, aluminum. In one embodiment, ring <NUM> is annular and has a <NUM> inch inside diameter and a <NUM> inch outside diameter wherein the ring is <NUM> inches thick (with <NUM> in = <NUM>). Moreover, ring <NUM> can be machined to minimize heat transfer from the reflector to the ring. The LED drivers of assemblies <NUM> can be mounted on the back side of ring <NUM> to power the LEDs mounted on the front side of the ring wherein they can operate at about <NUM> watts each. The electrical input to the drivers will range up to <NUM> volts AC. In addition to the drivers, finned heat sink(s) <NUM> can be mounted on the back side of ring <NUM>. In addition, enclosure <NUM> can include one or more heat sinks <NUM>.

According to one set of embodiments, output window <NUM> can be formed by quartz glass window. Yet even further, output window <NUM> can have one or more sections depending on performance goals include whether the sections are in line with IR source <NUM> or Visible light source <NUM>. These sections can be separate components and/or can be different portions of the same component. In this respect, output window <NUM> can be a part of an output window assembly <NUM> that can be fixed relative to enclosure <NUM> by any means known in the art. Window <NUM> can include a window section 126a that covers only IR source <NUM>. Window section 126a can be a quartz glass having a diameter of about <NUM> inches and a thickness of about <NUM>/<NUM> inches (with <NUM> in = <NUM>). Window section 126a can be configured to cover the output end of the <NUM> inch diameter parabolic reflector <NUM> of IR source <NUM>. This window section will transmit with very little attenuation IR in the range <NUM> to <NUM> microns in the beam from the IR source. The window can be held in place by any means known in the art including, but not limited to a narrow ring surrounding the outer <NUM>/<NUM> inch edge of the window and attached to the front of ring <NUM> (not shown).

A separate covering and/or section could be used for visible light assemblies <NUM> including individual covers for each of the lights <NUM>. Again, by using a quartz window for output window <NUM>, there is little or no absorption of IR radiation out to <NUM> microns and there is substantial radiation in the <NUM> to <NUM> micron range of light. Traditional glass envelopes of incandescent PAR lamps completely absorb infrared radiation of wavelengths longer than about <NUM> microns. This is important in that the IR cameras used are much more sensitive at <NUM> microns than at <NUM> microns and the invention of this application produces infrared at this more detectable range to utilize this greater sensitivity, which before now was not possible. But, this is not needed for the visible lights wherein an annular window section 126b can be used to cover the LEDs and which can be basic glass. Moreover, the light can include a cone shaped, heat transfer finned, electrically electroded cover that will form the base of this light (not shown).

As with light <NUM>, light <NUM> can include one or more filters <NUM> and/or 270a. Moreover, light <NUM> can include one or more filters for IR source <NUM> and/or visible light source <NUM> wherein filters <NUM> can be used for IR source <NUM> and filters 270a can be used for visible light source <NUM>. Filter(s) <NUM> can be configured to cover only the IR source, which is the preferred embodiment. However, filters <NUM> could be configured to cover the entire light opening. Similarly, filters 270a can cover only visible light source <NUM> and/or cover the entire window. In the preferred embodiments, filters 270a only cover the visible light source. Yet further, filters <NUM> and/or 270a can include and/or be part of the quartz window and/or part of the output window. With respect to filters <NUM>, these filters can include a "high pass" filter <NUM> that blocks radiation below a certain level and/or a "low pass" filter <NUM> that blocks radiation above a certain level, which was discussed in greater detail above.

Moreover, filter(s) <NUM> can include a combined filter wherein it can include more than one filter wherein, as is shown, filter <NUM> can include both a "high pass" filter <NUM> and a "low pass" filter <NUM> that can produce IR sources of particular ranges of wavelengths, which is discussed in greater detail above. Also, one or more of the filters can be part of window <NUM>. Again, that can include one or more IR bandpass filters that allow only the desired range of wavelengths to pass, which is discussed in greater detail above.

Filters 270a can also include filters (shown in the drawings as filters 272a and 274a) that control the passage of light, but these filters can be configured to control visible light. For example, filters 270a could include a color pass filter 272a wherein filters can be used to change the color and/or intensity of the visible light and/or any other type of light filter known in the art. As can be appreciated, while filters 272a and/or 274a are shown near window <NUM>, the filters can also be a part of internal light assembly <NUM> as is shown in <FIG>, individual light assemblies <NUM> and/or the LED light itself without detracting from the invention.

It has been found that the lights of this application produce significant increases in optical output power as compared to a standard incandescent PAR <NUM> style lamp. Therefore, the invention of this application can greatly exceed the IR output of a standard PAR style lamps with much less power consumption. Moreover, light <NUM> can also produce more visible light in addition to the increased in infrared output power without increases in power consumption.

According to yet even further embodiments, IR Sources <NUM>, <NUM> can be selectively operable infrared sources. As can be appreciated, and as is discussed in greater detail above, infrared is needed primarily when the weather conditions are unfavorable or the visibility is bad. When these conditions occur, a pilot uses an infrared (IR) camera or an enhanced flight vision system (EFVS) equipped in the cockpit to detect infrared rays emitted from the thermal source for safe landing. In greater detail, IR Sources <NUM>, <NUM> can be operable seperate from visible light sources. With respect to infrared produced from IR Sources <NUM>, the entire light <NUM> can be operable separate from other visible light sources used on the runway. As is discussed in greater detail above, lights <NUM> can be used in combination with visible light sources that can be separate fixtures wherein power can be supplied to IR sources <NUM> only when the conditions call for the use of infrared. Therefore, light <NUM> can include one or more systems and/or electronics for selective use wherein some of these will be discussed below in reference to light <NUM>.

In this respect, light <NUM> includes both IR source <NUM> and visible light source <NUM> wherein selective controls can be configured such that IR source <NUM> and visible light source <NUM> can be operated independent from one another. In greater detail, light <NUM> can include a wide range of internal electronics to allow independent operation between IR source <NUM> and visible light source <NUM> and the systems to allow for the control of the independent, or partially independent, internal systems and control.

With reference to <FIG>, one such system is shown schematically for light <NUM> as system <NUM>. System <NUM> is for light <NUM>, but some of these systems can be used for light <NUM>. In greater detail, light <NUM> includes both one or more IR source <NUM> and visible light source <NUM> wherein visible light sources includes one or more light assemblies <NUM>. In the embodiment shown, source <NUM> includes silicon nitride element <NUM> to produce the wide band infrared radiation and ceramic base <NUM> to hold the element in place within the light. IR source <NUM> is electrically connected by way of one or more wires <NUM> or the equivalent. Light assemblies <NUM> are operably connected to electrical system <NUM> by way of connection wires <NUM> or the equivalent.

System <NUM> includes a first electric circuit <NUM> and a second electrical circuit <NUM>, which can be any electric circuit known in the art, including, but not limited to, basic wired systems, wire harnesses and/or solid state systems. First circuit <NUM> electrically connects IR source <NUM> to system <NUM> and can include wires <NUM>. Second circuit <NUM> electrically connects light assemblies <NUM> to system <NUM> and can include wire <NUM>. System <NUM> further includes one or more switches <NUM> that operably connect circuits <NUM> and <NUM> to a power source <NUM> wherein switch <NUM> can selectively direct power between IR source <NUM> and visible light assemblies <NUM> based on environmental conditions or for any other reason. Circuit <NUM> and/or circuit <NUM> can include transformer(s) and/or electronic systems <NUM> and <NUM> that can control any variations in the delivered power including differences in voltage. However, as can be appreciated, these variations could also be manage directly within the light assemblies without detracting from the invention of this application.

System <NUM> can further include an internal operating system <NUM> that can include one or more sensors <NUM>. These sensors can include a wide range of sensor to detect environmental conditions. These sensors can include both internal sensors and external sensors including, but not limited to, light sensors <NUM> to detect the ambient light at the runway, pressure sensor <NUM> to detect changes in weather, temperature sensors <NUM> to detect the ambient temperature at the runway and/or an optics sensor <NUM> for window <NUM> to detect if the window has any form of obstruction, such as ice or snow.

System <NUM> and/or internal operating system <NUM> can further include one or more computing devices <NUM> that can control system <NUM> and/or light <NUM> including, but not limited to, managing power consumption to maximize efficiency and/or the use of IR source <NUM> and visible light source <NUM>. Any type of computing device could be used without detracting from the invention of this application including both internal and external computing systems. An output signal <NUM> can be sent to switch <NUM> to control the power flow between IR source <NUM> and visible light source <NUM>. However, in at least one embodiment, switch <NUM> can be part of operating system <NUM>. Operating system <NUM> and/or internal operating system <NUM> can further include an internal power supply <NUM> that can maintain the operation of system <NUM> even when light <NUM> is off and/or manage the power inflow to operating system <NUM> to allow system <NUM> to operating at different voltages and the like.

Operating system <NUM> can further include a communication system <NUM> that can include one or more antennas and/or transceivers <NUM> to allow system <NUM>, <NUM> to communicate with external operating systems and controls including an external computing device <NUM> (not shown). As can be appreciated, communication system <NUM> can be used to allow external communications to control the operation of the light. According to another set of embodiments, system <NUM> can include a standalone communication system <NUM> that can include one or more antennas and/or transceivers <NUM> to allow external communication to directly communicate with switch <NUM> with a switching signal <NUM> including, but not limited to, external computer networks (not shown).

System <NUM> can be electrically joined to base <NUM>, which can be the power source of the system and which includes electrical screw thread contact <NUM> and an electrical foot contact <NUM> of base <NUM> to produce an input power flow <NUM> to system <NUM>. Again, any power source and/or connection can be used to power lights <NUM>, <NUM>.

As a result, the IR source can operate independently and/or in conjunction with the visual light source depending upon the weather conditions. Moreover, the selective control of the IR source could also be used for other purposes, such as to melt ice and snow from the lens of the light when only the visible light source is required, but where snow and ice are impeding the efficiency of the visibility of the light.

Claim 1:
An airport runway light (<NUM>;<NUM>) for use as a runway approach light and runway light for a runway lighting system (<NUM>), the runway light (<NUM>, <NUM>) comprising a light body (<NUM>, <NUM>) having a base (<NUM>, <NUM>) configured to support the runway light in an associated light socket of an associated runway lighting system, the base including an electrical connection (<NUM>, <NUM>) to electrically connect the runway light to the associated runway lighting system, the light further including one or more output windows (<NUM>, <NUM>) wherein the runway light has a high-efficiency infrared source (<NUM>;<NUM>) characterized in that the runway light has one or more infrared parabolic reflectors (<NUM>, <NUM>) to direct the infrared source outwardly through the one or more output windows, said one or more parabolic reflectors (<NUM>, <NUM>) comprising a focal point (<NUM>), the infrared source having a silicon nitride element (<NUM>, <NUM>), the silicon nitride element (<NUM>, <NUM>) formed from a silicon nitride material, the silicon nitride element (<NUM>, <NUM>) extending from a silicon nitride element base (<NUM>, <NUM>) and having an element length of the silicon nitride material, the element length being longer than an element width and/or an element diameter of the silicon nitride material, the silicon nitride element producing a hot spot (<NUM>) of infrared radiation emanating from within the volume of silicon nitride material when electrified, the hot spot having a hot spot length (<NUM>) along the element length that is less than the element length and between the element base and the element distal end, wherein the hot spot (<NUM>) has both high intensity and significant beam concentration wherein the high intensity is at least closely aligned with the focal point (<NUM>) of the parabolic reflector(s) (<NUM>, <NUM>), the infrared source producing virtually no detectable visible light and with much less energy consumption than an incandescent PAR style lamp.