Patent Application
20100053971
The present invention relates to lighting systems and, in particular, to lighting systems providing an asymmetric distribution of light.
Luminaires for providing general illumination to an area are well known and often used in outdoor lighting applications including roadway and sidewalk lighting, parking lot lighting, and residential area lighting. Luminaires having symmetric light distributions can comprise a light source disposed within an external optic, wherein the external optic is designed to provide the symmetric light distribution. In one architecture, for example, a luminaire can comprise a light source disposed within a bell-shaped external optic, wherein the bell-shaped external optic provides a symmetric distribution of light to an area.
In some applications, however, a higher degree of control over light distribution from a luminaire is desirable. In some roadway lighting applications, for example, it is desirable to use luminaires having asymmetrical light distributions operable to provide the roadway and shoulder areas with higher luminous intensity in comparison with non-roadway areas such as grassy medians. Moreover, in some residential outdoor area lighting applications, it is desirable to use luminaires having asymmetrical light distributions operable to mitigate or prevent light trespass.
Asymmetric light distributions from a luminaire can presently be created through several avenues. One avenue is to design an external optic operable to create an asymmetric light distribution when a light source is disposed within the external optic. Design of an external optic operable to provide an asymmetric light distribution, however, is often cost prohibitive due to time intensive design processes that can strain engineering resources. Moreover, the design of the external optic is usually restricted to addressing a particular lighting need thereby precluding use of the design in a variety of applications.
Another avenue for producing an asymmetric light distribution from a luminaire is to externally couple a secondary optic to a primary optic, wherein the secondary optic is responsible for creating the asymmetric light distribution. A reflective bell-shaped primary optic, for example, can have a refractive secondary optic coupled thereto, wherein the refractive secondary optic produces an asymmetric light distribution. Such an arrangement is illustrated in
An additional avenue for producing an asymmetric light distribution from a luminaire is to block one or more portions of light from being transmitted by the luminaire. This avenue is disadvantageous since precluding portions of light from being transmitted by the luminaire reduces the luminous flux of the luminaire leading to inefficiencies and poor optical systems.
The present invention provides luminaires operable to produce asymmetric light distributions without the foregoing structural, cost, and efficiency disadvantages. Moreover, the present invention provides methods of providing an asymmetric light distribution to an area.
In one embodiment, a luminaire comprises a light source, an outer optic, and at least one inner optic at least partially positioned within the outer optic. The outer optic of the luminaire is adapted to direct a first portion of light received from the light source and a second portion of light received from the at least one inner optic resulting in an asymmetric light distribution from the luminaire. In some embodiments, an asymmetric light distribution comprises a radially asymmetric light distribution.
Any number of inner optics may be positioned at least partially within the outer optic. One or a plurality of inner optics may be retained at least partially within the outer optic via any retention method. In one embodiment one or more inner optics are at least partially positioned within the outer optic via a mounting bracket. The mounting bracket, in some embodiments, permits lateral, longitudinal, and/or radial adjustment of one or more inner optics. In this way, the relative positioning of the inner and outer optic is easily adjustable to permit tailoring the asymmetric light distribution of the luminaire. The ability to tailor the asymmetric light distribution of a luminaire can allow the luminaire to meet the requirements of a variety of applications without the cost considerations of having to redesign the luminaire for each intended application.
These and other embodiments are presented in greater detail in the detailed description which follows.
The present invention can be understood more readily by reference to the following detailed description, examples, and drawings and their previous and following descriptions. However, apparatus and methods of the present invention are not limited to the specific embodiments presented in the detailed description, examples, and drawings. It should be recognized that these embodiments are merely illustrative of the principles of the present invention. Numerous modifications and adaptations thereof will be readily apparent to those of skill in the art without departing from the spirit and scope of the invention.
The present invention provides luminaires operable to produce asymmetric light distributions without the structural, cost, and efficiency disadvantages associated with prior asymmetric lighting systems.
In one embodiment, the present invention provides a luminaire comprising a light source, an outer optic, and at least one inner optic at least partially positioned within the outer optic. The outer optic of the luminaire is adapted to direct a first portion of light received from the light source and a second portion of light received from the inner optic resulting in an asymmetric light distribution from the luminaire.
The outer optic works in conjunction with the inner optic to provide an asymmetric distribution of light from the luminaire. In one embodiment, the outer optic is adapted to direct light received from the at least one inner optic and light received directly from the light source in a longitudinal or substantially longitudinal direction. In directing light in a longitudinal or substantially longitudinal direction, the outer optic, in some embodiments, directs light out of the luminaire. Moreover, the at least one inner optic, in some embodiments, is adapted to direct light received from the light source in a transverse or substantially transverse direction. In directing light in a transverse or substantially transverse direction, an inner optic is operable to provide light received from the light source to the outer optic.
As provided herein, in some embodiments, a plurality of inner optics are at least partially positioned within the outer optic. In some embodiments, for example, a luminaire comprises two, three, four, five, six, seven, or eight inner optics.
In some embodiments of a luminaire of the present invention, the at least one inner optic is adjustable. In one embodiment, for example, the at least one inner optic is longitudinally adjustable. In another embodiment, the at least one inner optic is laterally adjustable. In a further embodiment, the at least one inner optic is radially adjustable.
In some embodiments wherein a plurality of inner optics are present, the inner optics are laterally, longitudinally, and/or radially adjustable independent of one another. In other embodiments, the plurality of inner optics are not independently adjustable and adjust in concert with one another. Adjustable inner optics, in some embodiments, permit tailoring the asymmetric light distribution of luminaires of the present invention. The ability to tailor the asymmetric light distribution of a luminaire of the present invention can allow the luminaire to meet the requirements of a variety of applications without the cost considerations of having to redesign the luminaire for each intended application.
In some embodiments, an inner optic has a V-shaped structure wherein the inner optic is bent at an angle θ. In some embodiments, θ is greater than about 90°. In some embodiments, θ is less than about 90°. In another embodiment, an inner optic has a curved structure. In one embodiment, an inner optic comprises an arc having a central angle of less than about 180°, less than about 90° or less than about 60°. In another embodiment, an inner optic comprises an arc having a central angle greater than 180°.
Referring now to the figures wherein like numerals indicate like elements throughout the various figures,
As illustrated in
In addition to facilitating longitudinal and/or lateral adjustment of the inner optics (204, 206), the mounting bracket (208) is operable to rotate. The collar (212) of the mounting bracket (208), for example, can comprise radial slots (220) permitting rotation of the mounting bracket (208). In one embodiment, bolts or screws (222) coupling the collar (212) to the base of the outer optic (202) and the base (224) of the luminaire (200) can be loosened and the mounting bracket (208) rotated to a desired position, the radial slots passing around the loosened bolts or screws (222) during rotation. After the desired position is achieved, the bolts or screws (222) are tightened to secure the collar (212).
In an alternative embodiment, the bolts or screws (222) can be removed and the mounting bracket (208) rotated to a new position and the bolts or screws (222) reinserted into a new position. In order to facilitate such an embodiment, the base of the outer optic (202) and the base (224) of the luminaire can have a plurality of bolt or screw (222) insertion points. As provided herein, rotation of the collar (212) results in radial adjustment of the inner optics (204, 206).
While the inner optics may be laterally, longitudinally, and/or radially adjustable independent of one another, they do not need to be independently adjustable but rather can adjust in concert with one another. Adjustable inner optics, while not required, permit tailoring the asymmetric light distribution of luminaires. The ability to tailor the asymmetric light distribution of a luminaire can allow the luminaire to meet the requirements of a variety of applications without the cost considerations of having to redesign the luminaire for each intended application.
While use of mechanical fasteners are disclosed for retaining the inner optics (204, 206) in position relative to the outer optic (202), the invention is not so limited. Rather, any retention method may be used, including, but not limited to, use of mechanical fasteners, interference fit, mechanical interlock, etc. Moreover, while the figures illustrate two inner optics (204, 206), any number of inner optics may be provided, depending on the desired light distribution. Furthermore, the geometry of the inner optics (204, 206) can be, but need not be, identical.
Moreover, the inner optics (204, 206) demonstrate one embodiment of a V-shaped structure, bent at an angle θ as provided herein. While V-shaped inner optics are illustrated in
An inner optic, in some embodiments, comprises a reflector, refractor, or combinations thereof. In some embodiments wherein a plurality of inner optics are present, the inner optics are constructed independently of one another. In one embodiment, for example, a first inner optic is a reflector and a second inner optic is a refractor. In another embodiment, a first inner optic is a reflector and a second inner optic is a reflector. Embodiments of the present invention contemplate any combination of reflector and refractor inner optics operable to achieve asymmetric light distributions in conjunction with the outer optic.
An outer optic of a luminaire of the present invention can comprise a reflector, a refractor, or a combination thereof. In some embodiments, wherein the outer optic is a reflector, the luminaire does not produce any significant uplighting and can achieve an IES Full-Cutoff designation. While the outer optic (202) illustrated in the figures is bell-shaped, it can be of any desired shape including, but not limited to, parabolic, spherical, or elliptical.
In some embodiments and as illustrated in
In some embodiments, wherein the luminaire has an open design, the outer optic and/or at least one inner optic comprise a radiation transmissive protective covering. In one embodiment, for example, a reflective outer optic comprises a radiation transmissive protective covering over the interior reflective surface of the outer optic. In some embodiments described herein, the interior reflective surface comprises specular enhanced aluminum panels hermetically sealed between the shell of the outer optic and a protective cover such glass, including but not limited to, borosilicate glass. In some embodiments, protective constructions for interior reflective surfaces of the outer optic comprise those provided in U.S. patent application Ser. No. 11/623,487 which is hereby incorporated by reference in its entirety.
Moreover, in another embodiment, a reflective inner optic comprises a protective covering over the reflective surface of the inner optic. Protective coverings for inner and outer optics of the present invention can comprise any material that does not substantially impair the ability of the inner and outer optics to perform their intended functions. In some embodiments, a protective covering comprises glass or polymeric materials. In one embodiment, a glass suitable for a protective covering comprises borosilicate glass.
Reflective inner and outer optics of the present invention can comprise any reflective material known to those of skill in the art as being suitable for use in reflective optics. In one embodiment, a reflective material for use in inner and outer optics of the present invention comprises polished metals such as, but not limited to, polished aluminum. In some embodiments a reflective material for use in inner and outer optics of the present invention comprises MIRO 4. In some embodiments, the reflectivity of inner and outer optics can be further enhanced by the application of reflective coatings, including reflective paints, or other reflective compositions.
Moreover, refractive inner and outer optics of the present invention can comprise any refractive material suitable for directing light in a manner consistent with embodiments described herein. In some embodiments, a refractive optic comprises a biconvex lens, a planoconvex lens, a planoconcave lens, or a biconcave lens. In other embodiments, a refractive optic comprises a positive meniscus lens or a negative meniscus lens. In some embodiments, a refractive optic comprises one or a plurality of prismatic structures. In one embodiment, a prismatic structure comprises Fresnel prisms. In some embodiments, one or a plurality of prismatic structures are present on at least one surface of an inner and/or outer optic.
Additionally, luminaires of the present contemplate any suitable light source known to one of skill in the art. In some embodiments, a light source comprises a HID lamp including metal halide lamps, high pressure sodium lamps, and mercury vapor lamps. In some embodiments, a HID lamp has any wattage up to 1000 W. In other embodiments, a HID lamp has a wattage greater than 1000 W. In another embodiment, a light source comprises a compact fluorescent lamp. In some embodiments, a compact fluorescent lamp has a wattage of 32 W, 42 W or 57 W.
Referring once again to the figures,
As illustrated in
As provided herein, in some embodiments, an inner optic comprises a continuous reflective surface. In some embodiments, the reflective surface of an inner optic has one or more creases or bends operable to reduce or preclude light normal to the inner optic from being directed back through the arc tube of a light source comprising a HID lamp. In some embodiments, for example, the reflective surface of an inner optic have a V-shaped structure being bent at and angle θ as described herein.
As demonstrated in
In addition to providing luminaires, the present invention also provides methods of lighting a surface. In one embodiment, a method of lighting a surface comprises providing a luminaire comprising a light source, an outer optic, and at least one inner optic at least partially positioned within the outer optic, directing to the surface a first portion of light from the light source with the outer optic, and directing to the surface a second portion of light from the light source with the inner optic and the outer optic, wherein at least one of the first portion of directed light and the second portion of directed light is asymmetrically distributed over the surface. In some embodiments, a surface comprises a roadway, sidewalk, parking lot, athletic field or residential area. In another embodiment, a surface comprises an indoor or outdoor work area.
In another embodiment, the present invention provides a method of changing the asymmetric light distribution of a luminaire on a surface. In one embodiment, a method of changing the asymmetric light distribution of a luminaire on a surface comprises providing a luminaire comprising a light source, an outer optic, and at least one inner optic at least partially positioned within the outer optic, adjusting the at least one inner optic, directing to the surface a first portion of light from the light source with the outer optic, and directing to the surface a second portion of light from the light source with the inner optic and the outer optic, wherein at least one on the first portion of directed light and the second portion of directed light is asymmetrically distributed over the surface.
In some embodiments, adjusting the at least one inner optic comprises longitudinally adjusting the inner optic. In another embodiment, adjusting the at least one inner optic comprises laterally adjusting the inner optic. In a further embodiment, adjusting the at least one inner optic comprises radially adjusting the inner optic. In one embodiment, adjusting the at least one inner optic comprises a combination of longitudinal, lateral, and or radial adjustment.
Luminaires according to embodiments of the present invention can be used in a variety of applications. In some embodiments, luminaires of the present invention can be used in outdoor lighting applications, including roadway, parking lot, and sidewalk applications as well as athletic field and residential area applications. In other embodiments, luminaires of the present invention can be used in indoor lighting applications, including warehouse lighting and workspace lighting applications.
Various embodiments of the invention have been described in fulfillment of the various objectives of the invention. It should be recognized that these embodiments are merely illustrative of the principles of the present invention. Numerous modifications and adaptations thereof will be readily apparent to those of skill in the art without departing from the spirit and scope of the invention.
