Patent Application
20110273877
The present disclosure relates to a lighting apparatus and, more specifically, to a lighting apparatus for illuminating traffic tunnels. Embodiments of the present disclosure can be particularly useful for distributing light emitted from one or more light emitting diodes (LEDs), as described herein, but may be used with any type of light source.
LEDs have improved in terms of quality, performance and cost, and their use and popularity have been growing. LED lighting provides, and has the further potential, to reduce the power consumption per unit lumen. This application is a divisional application of U.S. patent application Ser. No. 12/064,844 filed Oct. 6, 2008, which is a 371 nationalization of PCT/US2006/034,718 filed Sep. 6, 2006, which claims priority to U.S. Provisional Patent Application No. 60/714,428 filed Sep. 6, 2005.
Tunnel and bridge lighting have used incandescent, fluorescent and more recently high intensity discharge (HID) lamps that can provide adequate amounts of lighting, but which have several drawbacks, including frequent (at least annually) lamp failures and uneven lighting of the traffic surface and tunnel walls. Tunnels for highways and roadway can have earthen or rock walls and ceilings, or constructed walls or ceilings made or lined with concrete, ceramic tile, or other construction material. Tunnels also come in a wide variety of shapes and sizes. Some tunnels have a domed ceiling and wall shape, while others have vertical walls and substantially horizontal ceilings. Some tunnels are short, allowing one to easily see the exit to the tunnel even as one enters the entrance. Many tunnels are long enough that one can not see the exit port of the tunnel as one enters the entrance port and travels along the tunnel. Some tunnels are straight, while others have a curved roadway in the horizontal plane, while others may have a ascending or descending roadway.
In addition, driving through a tunnel at night requires different lighting than driving in the daytime. The variability in the types of tunnels and driving conditions makes it a challenge to develop a lighting system that can be installed and easily adapted to any tunnel.
The present disclosure provides a linear lighting system for lighting a traffic surface, comprising: a linear luminaire comprising a plurality of light sources disposed in a linear array along the length of the traffic surface, and a plurality of light-controlling means for directing the emitted light from the light sources at the traffic surface.
The linear lighting system is useful in the directional lighting of automotive traffic tunnels and bridges, train and subway stations and tunnels, and pedestrian hallways, walkways, corridors, canals and tunnels, and other traffic surfaces. In particular, the present invention provides a linear lighting system for lighting a traffic tunnel and its traffic surface, comprising: a linear luminaire comprising a plurality of LEDs or other light sources disposed in a linear array along the length of the traffic tunnel, and a plurality of light-controlling structures for directing the emitted light from the light sources at the traffic surface and/or the walls and ceiling of the traffic tunnel.
When the light source is a LED, the light-controlling structure for directing the emitted light from the light sources is selected from the group consisting of a refractor lens, a reflector, and a combination thereof. The light-controlling structure is configured to associate with the light sources to direct the emitted light predominantly toward the traffic surface, and/or toward the tunnel surfaces.
Embodiments of the present disclosure can also relate to a linear luminaire comprising:
1) a linear array light fixture;
2) an elongated light-transmitting window having opposed first and second longitudinal sides; and
3) an elongated housing having a base portion that encloses the frame, and a pair of arms extending from the base, the distal end of each arm receiving one of the opposed longitudinal sides of the elongated window, wherein the distal ends of the arms can be biased away from one another for insertion of the longitudinal sides of the elongated window. The linear array light fixture can utilize light sources such as LEDs and fluorescent tubes. A typical linear array light fixture comprises: a. an elongated light board comprising a plurality of LEDs arranged in a substantially linear array along the length of the board, and b. an elongated frame for supporting the elongated light board.
The elongated light-transmitting window is typically transparent. and typically made of a glass or a resilient plastic such as polycarbonate.
The receiving portion of each distal end of the arm may comprise a pocket or other structure that captures and secures the longitudinal side edge of the light-transmitting window.
The elongated frame is an elongated member that corresponds substantially in length with and engages and holds the elongated light board at a plurality of positions or entirely along the length, or can comprise a plurality of frame elements that can be configured to engage and support the elongated light board at its ends or along its length.
The housing typically is unitary and made from a resilient material that allows the ends of the arms to be biased outwardly but returns to a fixed position when unbiased by an external force. Typically materials for constructing the housing can be selected from the group consisting of metals, including stainless steel and aluminum, and plastics, such as acrylic and polyacrylic (Plexi-glass™), polyvinyl chloride (PVC), polycarbonate, and polystyrene.
The housing also may have a gasket to create a moisture seal between the longitudinal side of the light-transmitting window and the pocket or receiving portion of the arm of the housing. The housing also comprises structure for enclosing, preferably sealing off, the opposed longitudinal ends of the elongated housing. The light sources can have an associated light-controlling reflector having a proximal opening disposed around the base of the light sources, and a distal opening defined by a distal rim disposed adjacent to the inner surface of the elongated window to create a light barrier that prevents light from escaping between the rim and the inner surface of the window.
An embodiment of the present disclosure further relates to a method for lighting an automotive tunnel, comprising:
The LED lights are spaced apart by a horizontal distance of not more than 0.5 meter, and typically not less than 0.5 cm.
The present invention also relates to a method for lighting an automotive tunnel having high reflective tunnel walls, comprising the steps of:
Typically, the external surface of the walls are made using a material that has high reflectance, such as ceramic tile, concrete, as well as painted concrete and other painted surfaces. The reflective external surface typically has a reflectance of at least 30%, and more typically of at least 40%, and up to about 70%, and more typically up to about 60%, wherein emitted light from the plurality of LEDs is reflected by the reflective surface of the second wall to the traffic surface.
Typically LEDs are positioned along both the first and second tunnel walls, both having reflective surfaces.
An embodiment of the present disclosure also relates to a linear lighting system and a method for installing linear luminaires into a traffic tunnel, by employing a luminaire support system comprising: a plurality of power and control interface modules affixed to a tunnel wall at existing power nodes along the length of the tunnel wall; a plurality of luminaire support track sections affixed at a first end to a first power and control interface module, and at a second end to a second, adjacent power and control interface module; a plurality of linear luminaries, as described herein, affixed to the luminaire support tracks; and a means or structure for providing power from each power and control interface module to the linear luminaires. The luminaire support track sections can consist of two or more separate luminaire support tracks which are joined together. Each luminaire support track may be associated with one or more linear luminaire. In a typical embodiment, the luminaire support track is constructed to avoid attachment to or support from the tunnel wall at positions between adjacent power and control interface modules.
Aspects of the disclosure may be more fully understood from the following description when read together with the accompanying drawings, which are to be regarded as illustrative in nature, and not as limiting. The drawings are not necessarily to scale, emphasis instead placed on the principles of the disclosure. In the drawings:
While certain embodiments depicted in the drawings, one skilled in the art will appreciate that the embodiments depicted are illustrative and that variations of those shown, as well as other embodiments described herein, may be envisioned and practiced within the scope of the present disclosure.
As shown in
The linear array of LEDs can include a series of LEDs wherein some of the LEDs are staggered, for example where alternating LEDs are raised slightly above or dropped below a main line of LEDs.
The elongated light board 12 is typically a metallic clad resin board, typically aluminum clad, to help dissipate the heat of the LEDs. The LEDs 14 are powered by an AC or DC power source (not shown) that provides at least about 0.25 W per LED. The power source can also be associated with a means for electronic control of the current flow. Power sources and controllers are available from LSI Saco Technologies Inc. of Cincinnati, Ohio, and others. The luminous intensity and luminance from LEDs closely approximates a linear response function with respect to applied electrical current over a broad range of conditions. In addition, recent generations of AlInGaP, AlGaAs, and GaN LEDs draw less electrical power per lumen or candela of visible light produced than incandescent lamps, resulting in more cost-effective, compact, and lightweight luminaires.
A discrete LED component 14 is a conventionally available LED, and can include such LED devices such as T 1, T 1-¾, T 5, surface mount (SMD), axial-leaded “polyleds,” and high power packages such as the SuperNova, Pirahna, or Brewster lamps, all of which are available with a variety of options known to those skilled in the art such as color, size, and beam width, and can be obtained from manufacturers such as Hewlett Packard, Inc., Optoelectronics Division, located in San Jose, Calif. Osram Sylvania, Ltd. located in Danvers, Mass., Stanley Electric Company, Ltd. located in Tokyo, Japan, Philips-Lumiled located in Somerset, N.J., Nichia Chemical Industries. Ltd. located in Anan-shi. Tokushima-ken. Japan and many others. Discrete LEDs are the dominant form of LEDs in general use because of their generic shapes and ease of processing in standard printed circuit board assembly operations. A typical LED useful in the present invention is Philips' Luxeon® III Emitter LED.
The elongated light board 12 provides support for, delivers electrical power to, and maintains a spatial relationship between, the plurality of discrete LEDs 14. The structure of the elongated light board 12 will vary depending on the specific design of the LEDs 14 and of the linear luminaire 1. In a preferred embodiment, the light board 12 is a printed circuit board. A discrete LED 14 generally consists of a pre-assembled or packaged “lamp” which normally includes a metal lead frame or other substrate for electrical and mechanical connection and internal mechanical support, a semiconductor LED chip or “die”, a conductive adhesive or “die attach” for electrically and mechanically attaching one electrode of the chip to the lead frame or other substrate, a fine wire conductor for electrically connecting the other electrode of the chip to an area of the lead frame or other substrate which is electrically isolated from the first electrode and die attach by the chip itself. Finally, a clear, tinted, or slightly diffused polymer matrix enclosure is used to suspend, encapsulate, and protect the chip, lead frame, optional reflector cup and wire conductor, and to optionally provide certain desirable optical characteristics.
In a conventional LED 14, the polymer matrix enclosure typically comprises an optically clear epoxy or any number of materials capable of protecting the LED chip from environmental contaminants such as moisture. The upper portion of lead frame is connected to the LED semiconductor chip and a lower portion of lead frame extends out one end of the enclosure to attach to the printed circuit board 12 and provide electrical connection to an electronic control circuit through wires (not shown). The control circuit is operable to energize, control, and protect the LEDs 14, and manipulate and manage the illumination they produce. Many variations of electronic control circuit will be known to those skilled in the art and will vary depending on the application for linear luminaire 1.
A second configuration of LEDs can be a plurality of LED chips mounted in an intermediate manufacturing step directly onto a printed circuit board, ceramic substrate, or other structure to support the individual LED chip and provide electrical connections to it. When a plurality of LEDs is so mounted, the result is a “chip-on-board” LED array that in its entirety can then be incorporated into other assemblies as a subcomponent. Individual LED chips suitable for the present invention are available from Hewlett Packard, Showa Denko, Stanley, and Cree Research.
In most conventional discrete LED designs, the polymer matrix enclosure also functions as an integral optical element, such as a lens, deviator, or diffuser for the emitted light. The LEDs have the refractor element (e.g., refractor lens 21) molded into the LED. A separate or secondary optical refractor lens 21 can also be incorporated with the LED 14 to improve illuminator performance or appearance. The optical refractor lens 21 is positioned by support legs 22 attached to or supported by the printed circuit board 12 in position over the LED. The refractor lens 21 is normally a magnifier/collimator that serves to collect and project the light emitted by each conventional LED 14, into a narrower and more intense beam of directed light than otherwise would occur. The refractor lens 21 is commonly made separate from the polymer matrix enclosure, but can be made integrally. Lens 21 can also be made as an integral array of lenses that are then substantially registered about the centers of individual conventional discrete LEDs. In a preferred embodiment, the refractor lens 21 conform the emitted light into a conical pattern, such that the angle of the light having 50% light emittance, relative to the light emitted along the centerline through the LED, lays at an angle of about 12° from the centerline 100 through the LED, though more generally in the range of about 5° to about 35°.
A reflector 61, as shown in
In exemplary embodiments, the reflector 61 is positioned adjacent each LED 14 to surround the base of the diode. The reflector element 61 can have a frusto-conical shape, although other common cross-sectional shapes are elliptical and parabolic. The reflector 61 has a proximal opening 62 defined by proximal rim 65 disposed around the base of the LED bulb, and a distal opening 63 defined by distal rim 66 of the conical reflector wall 64. The inner surface 67 of the wall 64 can be highly reflective, to efficiently and effectively direct the emitted light of the LED that has an emission angle of about 90° to about 60° from the LED centerline 100. The light can reflect off of the inner reflective surface 67 at an angle substantially parallel to centerline 100. The conical cross sectional shape of the reflector element 61 as shown in
In exemplary embodiments, the distal rim 66 of the reflector element 61 is disposed adjacent to, and more typically, flush with the inner surface 53 of the elongated light transmitting window 50. The distal rim 66 of the reflector element 61 can be disposed directly against the inner surface 53 of the window 50 to create a light barrier that prevents LED light from escaping between the distal rim 66 and the inner surface 53 of the light-transmitting window 50. An optional optical sealing member or gasket can be disposed between the circumferential distal rim 66 of the reflector element 61 to improve the light barrier and the fit of the reflector element 61 against the window 50 during assembly.
As shown in
The printed circuit board 12 is shown partly withdrawn from the support frame 40, between the pair of inwardly-facing grooves 46. The support frame 40 may be of the same length as the printed circuit board 12 so that the longitudinal ends of the printed circuit board are flush with the ends of the support frame. The power and controls can be affixed to the back of the printed circuit board, or can be affixed to a second board disposed within another opposed pair of inner channels of the support frame 40. In exemplary embodiments, the power source and controller can be disposed remote from the assembly linear array light fixture, and connected to the light fixture by an electronic circuit that includes a separate circuit for electrical power and for electronic controls.
As shown in
The LED, refractive lens, and the printed circuit board are available individually or as a unit from LSI Saco Technologies Inc., Phillips Electronics, and Cree Inc. of Durham, N.C.
As shown in
The elongated housing 30 for the linear luminaire 1 typically encloses the linear array light fixture 10. The distal ends of the elongated arms 34 have a c-shaped pocket 36. The pockets 36 are configured to secure the longitudinal edges 52a and 52b of the window 50. The arms 34 extending from base 32 are configured to flex outward, away from one another, to allow the width of the window 50 to be slipped between the distal edges 54a and 54b of the opposed pockets 36a and 36b. In one embodiment, the housing can be made of stainless steel, aluminum, or a plastic such as polycarbonate, nylon, Plexiglass™, polyvinyl chloride (PVC), polystyrene and polyacrylic. A gasket material 60 is typically wrapped around and secured to both edges of the window 50 to create a waterproof seal along both the front face and rear face 53 of the window edges 52a and 52b, with the respective pockets 36a and 36b. The gasket material can be silicone, rubber, and other materials well known for use as a sealing gasket.
The housing 30 can include a means or structure for enclosing, preferably sealing, the opposed longitudinal ends of the linear array light fixture 10. The illustrated embodiment shows an end plate 70 that secures an end gasket 72 to each end of the housing 30, secured by a plurality of screws 99 that thread into the openings 49 of the support frame 40, to assembly the linear luminaire 1. The end plate can includes means or structure 96a,b for positioning and securing the assembled linear luminaire 1 to a light mounting bracket or track on the wall or ceiling of a tunnel, bridge or hallway, as shown in
The light transmitting window 50 can be made from a transparent glass or plastic material, to allow optimum transmission of the emitted light from the luminaire. Materials can include glass, such as quartz and silica, and plastic, such as Plexi-glass™, polycarbonate, polystyrene and polyacrylic. The window can be a rectangular shape in plan view. The window is typically planar, to pass maximally the light there through without any refracting of the passing light optically it can have a outwardly-facing concave shape to concentrate and/or direct or focus the light passing out the linear luminaire.
The lighting of tunnels for vehicle traffic has certain requirements, primarily related to safety. One requirement of the lighting system is to light the entrance and exits of the tunnel sufficiently to provide transition from the external luminance created by weather conditions and/or the position of the sun. Another important requirement for lighting is known as the flicker effect. In the interior of a lighted tunnel where luminaires or their reflected images are in full or partial view of the vehicle occupants, the stroboscope effect of passing closely spaced light sources may produce undesirable behavioral sensations and annoyance.
The linear lighting system of the present invention spaces the light sources at distances sufficiently close so that the stroboscopic effect is nominalized or avoided. The linear lighting system also is configured to direct the emitted light from the LEDs into a direction perpendicular from the surface of the tunnel wall and to the axis of the tunnel, to limit direct glare (that is, light emitted directly from an unshielded lamp) to operators and passengers of vehicles traveling through the tunnel. Light emitted “perpendicular” to a tunnel wall or a traffic surface can include light that is angled slightly, up to 10°, from true perpendicular.
The LEDs disposed in the light array light fixtures are arranged in a linear array along the length of the traffic surface 104. The rows of light luminaires bearing LEDs are arranged in series and preferably continuously. The rows of linear luminaries can be spaced end-to-end, or can have a minimum spacing sufficient to maintain adequate lighting and minimizing any stroboscopic effect. The LEDs that are spaced closely may give the appearance to a person passing along the length of the roadway that the light source is substantially continuous and linear.
Since nearly all existing tunnels and other roadway and other traffic surfaces are being lit by conventional light sources, it will be common for linear LED luminaries to be retrofitted into such facilities. This typically requires use of existing power and control circuits for the replacement of fluorescent, incandescent and HID lamp fixtures.
Exemplary embodiments of the present disclosure can relate to a linear lighting system and a method for installing linear luminaires into a traffic tunnel. The linear lighting system employs a luminaire support system that comprises: a plurality of power and control interface modules affixed to a tunnel wall at existing power nodes along the length of the tunnel wall; a plurality of luminaire support track sections affixed at a first end to a first power and control interface module, and at a second end to a second, adjacent power and control interface module; a plurality of linear luminaries, as described herein, affixed to the luminaire support tracks; and a means for providing power from each power and control interface module to the linear luminaires.
hi conventional tunnel lighting, power and control circuits are embedded into the side walls and/or ceilings of the tunnel. Lighting fixtures, such as HID, incandescent and fluorescent lamp fixtures are positioned along the length of the tunnel, along one wall or both walls or ceiling. Typically, a portion of the wall material is removed to accommodate the mounting of the power and control wiring and conventional light fixture. When the original or existing light system is removed, these fixture openings in the walls of the tunnel are available for installing of the new LED linear lighting system.
Along the length of the tunnel, power and control interface modules are installed. The power and control interface module typically consists of means for connecting any existing power or control circuits to the new linear lighting system, and a means to cover or secure the existing fixture opening, such as a cover plate. The cover plate covers the fixture opening, and mounts flush with the side wall of the tunnel, such as with bolts or similar hardware. Existing power and control circuits are threaded through liquid-tight ports in the cover plate, for connection with the linear luminaires of the linear lighting system.
The power and control interface modules also provide a means for attaching thereto luminaire supports that span the distance between two adjacent power and control interface modules. Depending on the distance between adjacent modules, the luminaire supports do not require direct connection to and support from the tunnel walls. The luminaire support can be a single element, or a plurality of connectable elements. The luminaire supports in turn are configured to support and secure the LED linear luminaire, and optionally any associated power and control circuits. The luminaire supports can be configured to hold the linear luminaire in a single position to direct the LED light away form the tunnel wall at a pre-determined angle, or can comprise further a means for adjusting the position of the linear luminaire to adjust the angle of direction of the LED light from the tunnel wall. The adjustment permits a single luminaire support system to be installed into any type of tunnel, or to simply fine-tune the lighting needs of any tunnel lit therewith.
The lighting system of exemplary embodiments of the present disclosure also allows for the replacement of the white (5500 K) LED lamps with different colored lamps (LEDs that emit a different visible color), or multi-color lamps (a single lamps that can emit a variety of different colors), to obtain particular lighting effects or advantages. For example, an LED or a group of LEDs can be used to identify exit lanes, locations of emergency phones, and fire and safety equipment, and to indicate other warnings or alerts, such as lane direction changes.
In exemplary embodiments, the plurality of linear luminaries 1 can be position along wall 110 or the ceiling 112, or both, of at least one side of the tunnel. The linear luminaries 1 can be positioned edge to edge, or with short spacing, to provide a substantially linear array of LED lights along the length of the tunnel. In the illustrated embodiment, the LED linear luminaire 1 is positioned near the top on each opposite tunnel wall 110a and 110b. In the embodiment shown in
In another embodiment, not specifically shown, the linear luminaries 1 can be affixed to the tunnel wall 110b in a linear array, and positioned to direct the emitted light along the centerline 100 of the LEDs at the far or opposite traffic lane 105a, and visa versa.
In another embodiment, not specifically shown, the linear luminaries 1 can be affixed to the tunnel ceiling 112 in a linear array, and positioned to direct the emitted light along the cen[0062] In yet another embodiment shown in
In yet another embodiment shown in
In a similar embodiment, the linear luminaries 1 are positioned along the tunnel ceiling 112, and positioned to direct the emitted light at either or both of the adjacent and far tunnel wall 110, and indirectly by reflection to the traffic surface 104. Such embodiments are particularly effective when the tunnel walls are made of reflective construction material, such as ceramic tile. The reflectance of a typical ceramic tile is more typically about 40-60%. An asphalt roadway, by comparison, has reflectance of about 10% or less. Consequently, a lighting system that provides a majority of the emitted light to the reflective tunnel walls, provides sufficient amounts of lighting to the roadway (through some direct lighting and from reflected light from the tunnel wall reflective surface) to effectively light the tunnel. The centerline 100 of the emitted light emitted from the ceiling is can be disposed toward the tunnel wall at an angle of about 15° to about 45° from vertical.terline 100 of the LEDs, at either or any of the traffic lanes 105.
Typical standards for the amount of lighting for tunnel walls and roadways are disclosed in Recommended Practices Standard 22 (RP-22), published by the Illuminating Engineering Society of North America (IESNA), the disclosure of which is incorporated herein by reference.
In alternative embodiments, additional linear arrays of the LEDS lights along the length of the traffic surface can be placed in locations offset from the first linear array, on other portions of the tunnel wall or the ceiling, as the design and requirements of the tunnel may indicate.
In one embodiment, a linear luminaire lighting system is shown in
A pair of luminaire support racks 86 and 83a are affixed at near ends to the module cover plate 81 with bolts 84B. The opposite end of first support track 83a is coupled with a splice channel 82 to a second support track 83b, secured by splice-track bolts 84D. Though not shown, the opposite end of second support track 83b is similarly coupled with another splice channel to a third support track 83c, to create a three-track unit. The splice channel 82 spans across a short space between the adjacent support tracks 83a and 83b, and overlaps the ends of the support tracks sufficiently for securement thereto. The opposite end of third support track 83c is secured to the next power and control interface module down the length of the tunnel, in a fashion identical to the attachment of track 86 to module plate 81 in
Within each length of track 83a, 83b and 83c is inserted a linear luminaire 1 according to the present invention. As can be seen in
As shown in
It should be understood from sectional view
The linear lighting system shown in
By comparison, the conventional incandescent, fluorescent, and HDD lamps of conventional tunnels provide areas of more intense illumination along the tunnel, on the roadway, tunnel walls, and ceiling, because of the wider illumination patterns of these lights that are typically spaced several meters apart. The large point light sources of a conventional tunnel also complicate the directing of the emitted light onto the traffic surface in a uniform manner, which therefore requires over-lighting some areas in order to obtain the minimum amount of lighting in all areas, and thus wasting both emitted light and electricity. By comparison, the linear luminaires of the present invention place the emitted light more precisely and uniformly upon the traffic surface, thus reducing the electrical power required to adequately illuminate the tunnel.
The present invention provides the use of light emitting diodes (LEDs) that are more energy efficient, up to 30% (and higher), and more generally up to 20%, more energy efficient with the same illumination than conventional lamps. The LED lights provide long light life of up to 50.000 hours, and in some embodiments, up to 100,000 hours and more, which far exceeds the average life of lamps of conventional light systems that use incandescent and HID (high intensity discharge) lamps. LEDs also have better sustained light performance than conventional incandescent and HID lamps, which can loose lumen output over time. LED light systems also operate with a lower voltage (for example, 15 volts or 24 volts DC, compared to conventional 120, 240 and 480 voltage AC systems), which improves operational and maintenance safety, and enables battery back-up. LEDs also have a shorter height compared to conventional lamps, enabling a lower luminaire profile. LEDs lighting also provides “instant on” light, as opposed to conventional HID lights that generally require an extended warm-up time (up to 10 minutes, or more).
LED lumen output is also more easily controlled based on the control of power into the LED lamp, as compared to the conventional lamps. The lumen output of one or a matrix of LEDs can also be varied linearly by adjusting the amps passed through the LED, and thus providing precise control of the amount of lumens required, and enabling variation of the total lumens of light emitted based on environmental conditions, such as daytime versus nighttime lighting. By comparison, conventional lamps typically come in unit sizes of 100 W, 150 W, 200 W, etc, such that the light emittance can not be readily controlled. The power controller means can be configured to dim some or all of the linear array light fixtures at a time, or for a period of time. The controller can also be configured to automatically engage dimming of the LEDs, based on a time cycle, outdoor brightness, or for other conditions.
The linear light source of the present invention also provides the advantage of reducing or eliminating the stroboscopic effect that can occur in tunnel and bridge lighting systems with conventional incandescent and HID lights.
The linear luminaire, and the linear lighting system, disclosed herein are particularly well suited for wet and dusty environments because their designs have no unsealed openings into electric contacts into which water and dust can gain egress. The design of the linear lighting system also has minimal external fasteners such as screws or bolts, on the front, top, or front surfaces of the system, which can accumulate dirt and which can snag the brushes of an industrial tunnel cleaning device which uses an aqueous washing solution sprayed at high pressures and the rotating bushes to dislodge dirt form the tunnel walls and light fixtures. The present design has a low profile, and few exposed corners and recesses, allowing such equipment to effectively clean both the tunnel wall and the linear luminaire lighting system with minimum breakage and damage to the equipment and to the luminaires. Improved tunnel and luminaire cleaning in turn provides better and brighter lighting within the tunnel.
Because of the long life and maintenance free operation of LEDs, the linear luminaires and linear lighting systems employing them are advantageously designed and constructed for equally long operating life, without requiring maintenance or replacement throughout the lifetime of the LEDs, typically 10 years, and often more. Environmental and operating factors that can affect the maintenance, repair, and replacement of the linear luminaires and linear lighting systems include the temperature with the tunnel and within the linear luminaire, maintenance within the tunnel that subjects the linear luminaires to dust, water and corrosion, and the exposure of the linear luminaires and the lighting system to physical damage from maintenance and cleaning equipment and vehicle traffic. Consequently, the metal parts of the linear luminaire and linear lighting system are preferably constructed of stainless steel or other non-corrosive, durable metal or plastic.
The present invention also provides the use of a lighting system for a tunnel, rail station, hallway, corridor and bridgeway that directs or focuses the emitted light onto the
traffic surface for more efficient use of the available lumens, and that provides a more uniform distribution of the light onto the traffic surface.
Optional conventional reflector panels can be associated with the linear array light fixture 10 or with the linear luminaire 1 to reflect light emitted from the plurality of LEDs disposed along the length of the fixture or luminaire, toward a direction along the centerline 100 of the LEDs.
While specific embodiments of the apparatus and method of the present invention have been described, it will be apparent to those skilled in the metalworking arts that various modifications thereto can be made without departing from the spirit and scope of the present invention as defined in the appended claims.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 12064844 | Oct 2008 | US |
| Child | 13101649 | US |
