Patent Application
20180335184
This invention relates to a luminaire system that meets the requirements of aviation obstruction lights and aviation airfield and heliport lights that require asymmetrical beam distribution patterns where the light intensity distribution about the optomechanical axis is biased such that the amount and intensity of light on one side of the optical axis is substantially greater than that on the other side. In addition, a luminaire system that meets the requirements of commercial and industrial area lights that require asymmetrical beam distribution patterns where the light intensity distribution about the optomechanical axis is biased such that the amount of light on one side of the optical axis is substantially greater than that on the other side.
Aviation lights for air fields, landing zones and obstructions or hazards to flight safety must meet detailed requirements for directional field of illumination, intensity distribution, color, duty cycle, pulse repetition rate, control, electrical, mechanical and environmental performance and durability. The United States Federal Aviation Administration (FAA) and international regulatory bodies govern the regulations, test and certification procedures for photometric, systems performance and durability.
The photometric requirements of lights and luminaire assemblies for specific purposes of aviation navigation, landing, take-off and flight control have detailed specifications for the distribution of light intensity dependent upon the placement and application. In order to meet the specifications for each type of luminaire, manufacturers typically use external optics to modify the illumination pattern from the light source (single or array of thermal, arc, or solid state devices) peculiar to the application. Conventional aviation obstruction lights employ lenses and/or mirrors with light sources to produce directional illumination patterns and intensity distributions for navigation aid to pilots and avionics systems within a design field of view for specific flight operation scenarios. The specifications for aviation obstruction lights on buildings, towers and other structures located away from air fields and landing zones include both requirements for intensity distribution in the field of view of the pilot and avionics, and restrictions on environmental light pollution or ground scatter sometimes referred to as residential annoyance factor. Conventional methods of optical systems design for mitigating ground scatter include off-axis optical elements, optics that tilt the optical axis, and baffles to vignette extraneous light illumination from the lower edges of the field of illumination incident on the ground and surrounding residential and commercial areas (e.g., Dialight and Hughley & Phillips).
The present invention is a luminaire system with directional light projection optics combined with a light distribution modifier secondary to the primary optics. The projection optics plus light distribution modifier produces a non-uniform angular light intensity distribution from a single or array of light sources. The combination of primary optics and light distribution modifier provides for light intensity distribution with directional asymmetry meeting the specifications and requirements of aviation obstruction lights in an efficient, cost-effective, manufacturable manner. The specific purpose of the light distribution modifier component or subassembly of the optical system is to redirect, scatter, refract, diffract and/or block part of the projection light in the distribution of the primary optics that would otherwise produce environmental light pollution, light producing residential annoyance, or in the case of commercial or industrial lights, extraneous glare and other light pollution to the surrounding environment. Unlike peripheral light shields at the marginal limits of the light distribution from the luminaire light system, the light distribution modifier is located near to the optical axis of the projection optics system.
In one embodiment, the light system subassembly of the luminaire comprises a heat-sink hub with printed circuit boards (PCB) mounted on the perimeter in sectors. Each PCB has an array of HBLED (High Brightness Light-Emitting Diode) light source elements of select colors (e.g., white, red and infrared). Primary reflector optic modules are mounted to the PCB with the HBLEDs. The reflectors have an upper and lower on and/or off-axis aspheric segments joined by a connecting base between the two reflector surfaces. The base has apertures for the illumination sources and registration hardware to locate and mount the reflector modules to the hub of the luminaire.
A light distribution modifier in the form of optically black shield is mounted to the hub-PCB assembly between the upper and lower reflector surfaces of each subassembly module. The upper and lower reflectors collect and redirect high angle light irradiation from the HBLEDs out the open aperture on either side of the light distribution modifier with a narrow beam spread of light in a distribution that has a peak at a positive angle (typically,1 to 2 degrees) above the horizontal optical axis. Direct LED radiation projects upward missing the reflectors in a narrow solid angle through a narrow aperture in the light distribution modifier close to the optical axis or is blocked by the light distribution modifier.
The light distribution modifier biases the overall light intensity distribution in the positive vertical direction above the optical axis and blocks the light that would project below the optical axis (horizontal) resulting in an asymmetric light intensity distribution in the positive vertical direction with sharp cut-off in intensity below the horizontal (where the horizontal is collocated with the optomechanical axis at zero degrees vertical). The luminaire optical assembly is completed with a transparent window for environmental protection of the hub and mounted optics (primary reflectors and secondary light distribution modifiers). The overall light distribution from the luminaire meets the photometric light distribution requirements for aviation obstruction lights including medium intensity white daylight with peak intensity at or above the horizontal, intensity between 15,000 and 25,000 candelas at the horizontal (zero degree vertical), intensity between 7,500 and 11,250 candelas at −1 degree vertical, ground scatter intensity less than 3 percent of the peak intensity at −10 degree vertical, and beam spread of greater than 3 degrees.
In one embodiment, a luminaire system comprises at least one light source, a reflector module, and a light distribution modifier, connectable to the reflector module, that produces a structured “elliptical” light distribution with peak intensity above an optical axis and a sharp cut off in intensity below the optical axis.
In another embodiment, a luminaire light system comprises at least one printed circuit board, at least one light source mounted to the at least one printed circuit board, a reflector module connected around the at least one light source, and a light distribution modifier having an upper portion connected to the reflector module and a lower portion connected to the reflector module, the upper portion is separated from the lower portion by a distance, the light distribution modifier producing a light distribution with peak intensity above an optical axis and a sharp cut off in intensity below the optical axis.
In another embodiment, a luminaire system comprises an array of light emitting diodes (LED) modules, a reflector module surrounding the array of LED modules, and a light distribution module having a slit aperture positioned along an optical axis, the light distribution module comprising an upper portion and a lower portion, wherein each the upper portion and the lower portion where at least a first part extends a distance from the reflector module and a second part is positioned in a direction perpendicular to the optical axis.
In another embodiment, a luminaire system comprises arrays of light emitting diodes on PC boards, reflector modules surrounding each array of LED modules, and a light distribution modifier module spaced in the field of the LED modules and reflector optics populating all sectors of the hub assembly to produce an omni-directional luminaire of uniform intensity distribution over 360 degree horizontal and defined asymmetrical vertical distribution meeting the specifications for peak intensity, intensity at zero degrees vertical, beam spread, intensity at −1 degree vertical and intensity at −10 degrees vertical.
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention.
Reflector module 1 is mounted to the PCB 3 and hub 2 by mechanical fixation known to those skilled in the art. Reflector module 1 has an upper reflector surface 1A, and a lower reflector surface 1B. These reflector surfaces 1A, 1B reflect light from the LED 4. The reflector surfaces 1A, 1B can be curved as shown in
Light distribution modifier 5 is mechanically fixed and registered to the reflector module 1, PCB 3 and hub 2. Light distribution modifier 5 has a clear aperture or slit 5A normal to the direction of illumination of the LED light source on optical axis 7. Light distribution modifier 5 is located a distance 8 from the LEDs in the far field from the LEDs, for example about 10 mm distance.
In an alternative embodiment, the light distribution modifier is opaque and effectively blocks part of the light pattern of radiation form the light source.
In a further alternative embodiment, the light distribution modifier is opaque and effectively blocks part of the light pattern of radiation from the light source but the lower surface of the light distribution modifier is reflective thereby reflecting and redirecting light from the light source incident on the lower surface to secondary reflection from the upper or lower reflector such that the light distribution intensity from the optic assembly is biased to positive vertical direction on the plus side of the optical axis.
In another alternative embodiment, the light distribution modifier incorporates a refractive optical element for example but not limited to a wedge prism, an array of microprisms, a positive or negative lens off-axis or tilted, microlens assembly or other refractive optic to refract light incident on the light distribution modifier in the positive vertical direction of the light distribution from the luminaire system.
In another alternative embodiment, the light distribution modifier incorporates a transmissive diffractive optical element for example but not limited to a transmission grating, or a Rhonchi ruling, binary optic, structured light modifier, light shaping diffuser, or other diffractive optic to diffract light incident on the light distribution modifier in the positive vertical direction of the light distribution from the luminaire system.
In another alternative embodiment, the light distribution modifier incorporates a mesoscopic array structure or a nanoscopic array structure or antenna array structure to redirect light incident on the light distribution modifier in the positive vertical direction of the light distribution of the luminaire system or toward the upper or lower reflector surface thereby contributing to the overall intensity distribution with bias in the positive vertical direction of the luminaire system by means of secondary reflection from the upper or lower reflector or redirection in the positive vertical direction without secondary reflection from the upper or lower reflector.
Light distribution modifier 5 has an upper portion and a lower portion. The upper portion of the light distribution modifier 5 has one or more arms 5B that extends as shown in
In one embodiment, the LED light source can comprise an array of HBLED (High Brightness Light-Emitting Diode) light source elements of select colors (e.g., white, red and infrared). The LED light source can be one color or a mixture of visible colors, infrared, ultraviolet, or a mixture thereof of different wavelength LEDs.
As illustrated in
In alternative embodiments, the light distribution modifier 5 may be one piece, where the upper portion 5D and the lower portion 5E join together with a clear aperture or lens between them so that light would be emitted therefrom along the optical axis. Moreover, in alternative embodiments, the arms 5B, 5C (
Light rays from the LED source 4 projecting over the angular field θ2 reflect from the upper reflector surface 1A in a direction approximately or substantially parallel to optical axis 7. Light rays from the LED source 4 projecting over the angular field θ3 reflect from the lower reflector surface 1B in an angular direction slightly positive to the optical axis 7.
Light rays from the LED source 4 projecting over the angular field θ2 that reflect from the upper reflector surface but are incident on the outer edge of light distribution modifier 5 distance 8 from the LEDs, diffract from the light distribution modifier 5 at high angles outside of the field of interest and specification for the aviation light assembly. Light rays from the LED source 4 projecting over the angular field θ4 that miss the upper reflector surface project in the positive vertical distribution of the aviation light assembly thereby increasing the beam spread of the luminaire for enhanced visibility to a pilot approaching the obstruction light.
Light rays from the LED source 4 projecting over the angular field θ3 that reflect from the lower reflector surface but are incident on the outer edge of light distribution modifier 5 distance 8 from the LEDs, also diffract from the light distribution modifier 5 at high angles outside of the field of interest and specification for the aviation light assembly.
Light rays from the LED source 4 projecting over the angular field ø1 that are incident on the upper back side of light distribution modifier 5 are blocked and do not contribute to the light distribution from the aviation light assembly in the far field. Light rays from the LED source 4 projecting over the angular field ø2 that are incident on the lower back side of light distribution modifier 5 are blocked and do not contribute to the light distribution from the aviation light assembly in the far field.
Point 9 on the photometric intensity distribution represents intensity in the horizontal direction. The typical specification for aviation medium intensity daylight flashing obstruction light is between 15,000 and 25,000 effective candela (ecd).
Point 10 on the photometric intensity distribution represents the peak intensity which is biased at a positive angle above the horizontal to provide greater visibility to a pilot on approach to the obstruction at a typical angle of approach for landing 16 between 3 and 6 degrees above the horizontal.
Point 11 on the photometric intensity distribution represents intensity at −1 degree below the horizontal. The typical specification for aviation medium intensity daylight flashing obstruction light at −1 degree below the horizontal is between 7,500 and 11,250 effective candela (ecd).
Point 12 on the photometric intensity distribution represents intensity at −10 degrees below the horizontal. The typical specification for aviation medium intensity daylight flashing obstruction light at −10 degrees below the horizontal is less than 3 percent of the peak intensity.
Points 14A and 14B on the photometric intensity distribution represent secondary peak intensity outside of the field of angular specification that are a property of the diffraction of light from the edges of the light distribution modifier in
The beam spread of the photometric intensity distribution is represented by the angular range 13. The typical specification for aviation medium intensity daylight flashing obstruction light beam spread is greater than 3 degrees at half minimum intensity specification, 7,500 ecd.
As illustrated in
Although the light distribution modifier 5 and 20 preferably comprises non-reflective surfaces, light distribution modifier can have alternative designs, such as reflective flat or curved surfaces for the external surface facing toward the LED or array of LEDS. The surface facing away from the LEDs can still be a non-reflective surface. Reflective surfaces can be made any material known to those skilled in the art. The intensity of the light pattern can be enhanced by the design of the reflective surface of light distribution modifier.
Although the position of the shield (i.e., the end piece or backstop) of light distribution modifier 5 and 20 is preferably perpendicular to the optical axis 7, designs of the light distribution modifier can be made where the position of the shield is something other than perpendicular to the optical axis 7. Such a design may be used to direct light toward either or both of the reflector modules 1A or 1B or in some other direction.
A particular configuration of the light distribution modifier 5 is based on specifications and requirements of a particular aviation obstruction light. This means that the required intensities of light in particular directions as detailed in a particular specification will drive the specific design of a light distribution modifier, including for example (1) where the light distribution modifier is positioned in the reflector module which is dependent on the number of LEDS and the positioning of other parts of the reflector module; (2) specific lengths, heights and widths, and various angles between the pieces that comprise the light distribution modifier; and (3) the durability and stiffness of particular pieces of the light distribution modifier.
An example of the intended use of the invention is an aviation obstruction light producing high intensity visible light over a narrow beam spread in the field of view of the pilot of an approaching aircraft while at the same time producing negligible ground scatter low light intensity below the horizontal to minimize residential annoyance.
In an alternative embodiment, the reflector module is inverted such that the upper and lower reflectors in combination with the light distribution modifier project a structure light distribution with a peak intensity below the optomechanical axis of the light assembly and light distribution that is biased in the negative vertical direction with a sharp intensity cut off above the optical axis. An example of the intended use of this alternative embodiment would be a flood light in aviation application for illuminating a landing zone or ground terminal area of an airport or heliport for pilot and airport personnel without creating light noise to pilots on approach to the airport. Another example of the intended use of this alternative embodiment would be a flood light in a commercial application for illuminating a storage area of a port or industrial park or a parking lot.
