Patent Publication Number: US-2016230964-A1

Title: Apparatus, method, and system for highly controlled light distribution using multiple light sources

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of co-pending U.S. Ser. No. 13/659,515 filed Oct. 24, 2012, which application is a continuation of co-pending U.S. Ser. No. 12/751,519 filed Mar. 31, 2010, now Pat. No. 8,449,144 issued on May 28, 2013, which is a continuation-in-part of co-pending PCT application No. PCT/US09/57090 filed Sep. 16, 2009, and co-pending U.S. Ser. No. 12/467,160 filed May 15, 2009, now Pat. No. 8,356,916 issued on Jan. 22, 2013, both of which claim priority to provisional U.S. Ser. No. 61/097,483 filed Sep. 16, 2008 and U.S. Ser. No. 61/054,089 filed May 16, 2008, all of which are hereby incorporated by reference in their entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention generally relates to systems and methods for lighting. More specifically, the present invention relates to an adjustable lighting fixture utilizing light emitting diodes (LEDs) to produce highly controlled and highly customized lighting. 
     In the current state of the art, the light projected from a fixture is often characterized in terms of the pattern of light as viewed on a target area; this is often referred to as the beam distribution type, beam type, or beam pattern. Beam distribution types are well known in the state of the art and are well defined and standardized by various organizations (e.g., the Illuminating Engineering Society (IES)). 
     Various light source types (e.g., HID, LED) can produce a given beam type via use of optical elements (e.g., reflective or refractive lenses). With LEDs, for example, a fixture may comprise a plurality of LED light sources, each light source coupled with an optic such that the composite beam (i.e., the collective of each beam projected from each LED) is of a particular beam distribution type. One example of this in the current state of the art are THE EDGE™ fixtures—available from Beta Lighting Inc., Sturtevant, Wis., U.S.—which use an array of identical NANOOPTIC™ refractors to produce a specific beam distribution type. 
     One disadvantage to such current art approaches is that the designed optics are only useful in producing a single beam type; they must be modified or replaced if a different beam type is desired. In the case of LEDs, this can require the modification or replacement of dozens of optics. Additionally, such fixtures afford little flexibility; a type II beam pattern (as defined by IES) may be sufficient to illuminate a target area but if the target area changes (e.g., the area to be illuminated is increased, the target area is moved), or the lighting needs change (e.g., spill light needs to be eliminated, glare needs to be controlled), the beam type may no longer be appropriate for the application. Of course, the fixture itself may be adjusted about a particular axis to positionally shift the projected light, but this will not significantly change the beam type. 
     The current state of the art may benefit from improved design of lighting fixtures such that projected light from said fixtures may be customized to produce beam patterns beyond those which are well defined and standardized in the industry. Further, the art may benefit if the components of lighting fixtures may be made modular such that components may be switched in and out onsite to facilitate fast, easy, and cost-effective customization of a projected beam type. Thus, there is room for improvement in the art. 
     I. SUMMARY OF THE INVENTION 
     Envisioned are apparatus, method, and system for lighting fixtures which comprise adjustable components to facilitate customization in lighting a target area in a manner that allows greater control over light distribution and light intensity than in some fixtures in the current state of the art. Embodiments of the present invention are described with reference to LEDs and LED lighting, however, embodiments of the present invention are equally applicable to other solid state light sources, other lighting devices (e.g., lasers), or other fixtures that allow for multiple light sources to be packaged together in a small area. 
     It is therefore a principle object, feature, advantage, or aspect of the present invention to improve over the state of the art and/or solve problems and deficiencies in the state of the art. 
     Further objects, features, advantages, or aspects of the present invention may include one or more of the following: 
     a. producing a composite beam which may include standard beam distribution types and/or customized beam types; 
     b. producing a composite beam from a plurality of individual beams, each individual beam being produced from a selection of a relatively small number of fixture components; 
     c. locating fixture components relative to the light source in a manner that maintains tight control over light distribution; and 
     d. developing a fixture in which fixture components may be aimed prior to installation but may also be aimed, adjusted, or switched with other fixture components onsite after installation. 
     One aspect of the invention comprises an apparatus including a plurality of solid state light sources, positioning rings, and optical components. 
     Another aspect of the invention comprises a method of designing an optic system including one or more of: (a) a light distributing member and (b) a light blocking member. Another aspect according to the invention is illustrated in  FIG. 1A  in which a composite beam  200 , which may be produced by the apparatus or method described above, is formed from individual light beams  210  from a single fixture  10 ; note only a few light beams  210  are illustrated in  FIG. 1A  and are not representative of the number of light beams produced from fixture  10 . Alternatively, as illustrated in  FIG. 1B , a composite beam  220  may be formed from individual light beams  210  from multiple fixtures  10  which may be affixed to a single pole  11 ; again, for purposes of demonstration and brevity, only a few beams  210  are illustrated. 
     These and other objects, features, advantages, or aspects of the present invention will become more apparent with reference to the accompanying specification. 
    
    
     
       II. BRIEF DESCRIPTION OF THE DRAWINGS 
       From time-to-time in this description reference will be taken to the drawings which are identified by figure number and are summarized below. 
         FIGS. 1A and 1B  illustrate the creation of a composite beam from a plurality of individual beams according to one aspect of the present invention. 
         FIG. 2  illustrates one possible lighting fixture according to at least one aspect of the present invention. 
         FIG. 3A  illustrates a perspective view of a subassembly which is housed in the lighting fixture of  FIG. 2 . 
         FIG. 3B  illustrates, in exploded form, the components of the subassembly of  FIG. 3A . 
         FIG. 3C  illustrates, in exploded perspective view, details of some of the components of the subassembly of  FIG. 3A . 
         FIGS. 4A-D  illustrate various views of the locating ring according to at least one aspect of the present invention. 
         FIGS. 5A-E  illustrate various views of the reflector according to at least one aspect of the present invention. 
         FIGS. 6A-D  illustrates various views of the visor base according to at least one aspect of the present invention. 
         FIG. 7  illustrates a top view (with respect to  FIG. 3A ) of the circuit board according to at least one aspect of the present invention. 
         FIG. 8  illustrates a top view (with respect to  FIG. 3A ) of the retaining plate according to at least one aspect of the present invention. 
         FIGS. 9A and 9B  illustrate photometric data for an LED with a standard parabolic reflector.  FIG. 9A  illustrates an isocandela diagram and  FIG. 9B  illustrates a footcandle diagram. 
         FIGS. 9C and 9D  illustrate photometric data for an LED with a modified reflector.  FIG. 9C  illustrates an isocandela diagram and  FIG. 9D  illustrates a footcandle diagram. 
         FIGS. 9E and 9F  illustrate photometric data for an LED with an alternative modified reflector.  FIG. 9E  illustrates an isocandela diagram and  FIG. 9F  illustrates a footcandle diagram. 
     
    
    
     III. DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     A. Overview 
     To further understanding of the present invention, a specific exemplary embodiment according to the present invention will be described in detail. Frequent mention will be made in this description to the drawings. Reference numbers will be used to indicate certain parts in the drawings. The same reference numbers will be used to indicate the same parts throughout the drawings. 
     Aspects according to the present invention provide for a lighting fixture—using LEDs or other solid state light sources—which projects a composite beam that is customizable and adjustable; customizable in that a desired beam distribution pattern (which may or may not be a standard beam pattern per the lighting industry) may be effectuated from a relatively small number of fixture components, and adjustable in that components may be traded out onsite if lighting effect changes (e.g., glare control, spill light control) are desirable. 
     As has been stated, the projected composite beam may be comprised of light emitted from a plurality of light sources in a single fixture (see  FIG. 1A ) or a plurality of fixtures (see  FIG. 1B ); likewise, the composite beam may include light projected from multiple light sources that are housed on multiple poles (see reference no.  11 ). It is of further note, that as described in aforementioned PCT application No. PCT/US09/57090, U.S. application Ser. No. 12/467,160, and U.S. provisional application No. 61/097,483, the composite beam may comprise overlapped individual beams similar in shape (e.g., to obtain a desired illumination), overlapped or juxtaposed individual beams different in shape (e.g., to obtain a desired beam shape), or some combination thereof to address lighting needs. In essence, the composite beam may comprise any number of individual beams each of which may be adjustable in terms of shape, size, intensity, aiming and/or orientation relative to the fixture, or otherwise. Specific methods of designing such composite beams are discussed in the aforementioned parent patent applications, which are incorporated by reference in their entirety. 
     B. Exemplary Method and Apparatus Embodiment I 
     A more specific exemplary embodiment, utilizing aspects of the generalized example described above, will now be described.  FIG. 2  illustrates one possible lighting fixture  10  which houses multiple LEDs and comprises an aluminum housing  14 , a removable panel  13  for access to the power regulating devices associated with the LEDs (which are well known in the art of lighting), a removable lens  15  for access to the LEDs and associated optics, and an adjustable mounting knuckle  12  for mounting lighting fixture  10  to a pole  11  or other structure. As described in the incorporated-by-reference parent patent applications, lens  15  may further comprise an anti-reflective coating which, as is well known in the art of lighting, may allow for a variety of angles of incidence up from normal. 
       FIGS. 3A-C  illustrate a subassembly  20  housed in fixture  10  which comprises a thermal interface layer  27 , LED circuit board  21 , LEDs  22 , locating ring  23 , reflector  24 , visor base  25 , and retaining plate  26 . As illustrated, subassembly  20  houses twenty-four LEDs with assorted components; however this is by way of example and not by way of limitation. 
     Thermal interface layer  27  may be of any available type; the primary purpose of layer  27  is to fill the space between circuit board  21  and housing  14  to facilitate heat dissipation; housing  14  acts as a heat sink for LEDs  22 . LEDs  22  can be model XP-G available from Cree, Inc., Durham, N.C., USA, though this is by way of example and not by way of limitation. 
     A detailed view of circuit board  21  is illustrated in  FIG. 7 . As can be seen, LED board  21  comprises positioning points  31  for LEDs  22  and a pair of apertures  32  for positioning locating rings  23  about position points  31  (and, therefore, LEDs  22 ). With further respect to  FIG. 7 , LED circuit board  21  comprises bolts  34  (or analogous components) which affix board to housing  14 . Apertures  33  are adapted to receive bolts (or analogous components) extending through retaining plate  26 , which is illustrated in  FIG. 8 . As can be seen from  FIG. 8 , formed portions  36  of retaining plate  26  are shaped to accommodate the bolt heads of bolts  34  in circuit board  21 . Bolts  35  through retaining plate  26  extend through apertures  33  and affix retaining plate  26  and circuit board  21  to housing  14 . 
       FIGS. 4A-D  illustrate locating ring  23  in more detail; as can be seen, pegs  37  are adapted to fit in apertures  32  of LED circuit board  21 . Ridge  38  of locating ring  23  is adapted to fit in channel  39  of visor base  25  (see  FIG. 6A ). When ridge  38  is seated in channel  39 , reflector  24  is positionally affixed in visor base  25  and pivotable relative to LED  22  (see  FIGS. 3B and 3C ). The use of locating ring  23  is an improvement over the current state of the art because it helps to maintain alignment of reflector  24  relative to LEDs  22  which, according to one estimate, is required to be on the order of ±0.02″ to maintain adequate control of light distribution. For example, according to one method in the current state of the art a large plate with pre-punched apertures is laid over optical elements (similar to reflector  24 ) so to both align and positionally affix said optical elements. While functional, such plates must maintain tolerancing relative to each LED across the length of the entire part, which may be on the order of one foot or more. Alternatively, locating ring  23  is on the order of one inch in diameter and since there is a locating ring associated with each LED  22 , strict tolerancing for each LED is more readily attained. 
     With regards to  FIGS. 6A-D , visor base  25  further comprises grip tabs  40 , visor  41 , alignment marker  42 , and ridge  43 . As envisioned, visor base  25  is of polymeric composition with visor  41  metallized to act as a reflecting surface for light emitted from LED  22 . Visor base  25  is adapted such that ridge  43  is compressed under retaining plate  26  with grip tabs  40 , visor  41 , and alignment marker  42  projecting through aperture  44  of plate  26 ; see  FIG. 3A . As envisioned, visor  41  projects 37° upward from horizontal (i.e., the plane of retaining plate  26 ), though other angles, sizes, and shapes of visor  41  are possible and envisioned. 
       FIGS. 5A-E  illustrate reflector  24  in more detail; as can be seen, reflector includes facets  45  which are metallized on the inner surface to aid in reflecting and a notch  46  to provide downward lighting. Tab  47  of reflector  24  is adapted to fit in notch  48  of visor base  25  such that, when ridge  38  of locating ring  23  is seated in channel  39  of visor base  25 , metallized surfaces on visor  41  and reflector  24  are facing each other, are fixed relative to each other, surround LED  22 , and may pivot 360° about LED  22 . As envisioned, reflector  24  is a modified parabolic design produced by methods described in the incorporated-by-reference parent patent applications; however, this is by way of example and not by way of limitation. Other reflector designs are possible, and envisioned. For example, a reflector designed to allow for downlighting may be used in some subassemblies  20  of fixture  10  while other subassemblies  20  in the same fixture  10  use reflector  24 ; this combination of reflector designs allows adjustability of any portion or all of the composite beam in both the horizontal and vertical axes. 
     However, the design of reflector  24  offers some benefits over previous designs; namely, the ability to create a larger, more even beam pattern that is better suited to overlapping to build a composite beam. For example,  FIGS. 9A  and B illustrate isocandela and footcandle diagrams, respectively, for a standard parabolic reflector 10′ above the target area using a Cree XR-E LED; it of note that aiming is 70° to nadir to allow for a more direct comparison to  FIGS. 9C-F .  FIGS. 9C and 9D  illustrate isocandela and footcandle diagrams, respectively, for the modified parabolic reflector disclosed in the parent patent applications 10′ above the target area using a Cree XR-E LED.  FIGS. 9E and 9F  illustrate isocandela and footcandle diagrams, respectively, for reflector  24  at 10′ above the target area using a Cree XP-G LED. Comparing diagrams for the three reflector designs illustrates the progression from a spot-type beam where light transitions abruptly from intense light to no light, to a spread-type beam where projected light transitions gradually across the enlarged lighted area. 
     According to one possible method, a lighting designer or other person(s) determines the lighting needs (e.g., size, desired illumination level) of a particular area and determines which fixture components are suitable for the application (e.g., different shapes of reflector  24  may be available, different color or size of LEDs  22  may be available). Circuit board  21  is secured to housing  14  via bolts  34 , thermal interface layer  27  filling the space between the bottom of circuit board  21  and the inner surface of housing  14 . LEDs  22  are then placed at positioning points  31  on the secured board and the necessary electrical connections made. Locating rings  23  are then placed about LEDs  22  by placing pegs  37  of rings  23  in apertures  32  of secured circuit board  21 . Reflectors  24  are placed in the center aperture of visor bases  25  by securing tabs  47  of reflectors  24  in cutouts  48  of visor bases  25 . Reflector/visor bases  24 / 25  are then placed on locating rings  23  by securing ridges  38  of locating rings  23  in channels  39  of visor bases  25 . 
     Optical elements are placed in their correct orientation by pivoting visor base/reflector  25 / 24  about LEDs  22  by grip tabs  40 ; grip tabs  40  are beneficial to the design because they allow one to pivot visor base/reflector  25 / 24  about LEDs  22  without touching (and possibly diminishing the effectiveness of) metallized surfaces or damaging parts. Initial orientation of fixture components may be determined according to methods described in the incorporated-by-reference parent patent applications or otherwise. 
     Once all optical elements are oriented, indexed, or otherwise aimed, retaining plate  26  is lowered into housing  14 , centered about optical elements, and bolts  35  are tightened (as stated, bolts  35  pass through apertures  33  in secured circuit board  21  before being secured to housing  14 , helping to ensure alignment of the fixture components relative to each other and relative to housing  14 ). Remaining electrical connections are made, lens  15  is affixed to fixture  10 , fixture  10  is mounted to pole  11  and powered, and fixture  10  is aligned via mounting knuckle  12 . If at some point lighting needs change, fixture components fail or become damaged, or otherwise, aiming of fixture components may be changed by loosening bolts  35  and pivoting visor bases/reflectors  25 / 24  via grip tabs  40 ; alternatively or in addition, visor bases  25  and/or reflectors  24  may be switched out. If optical elements are realigned, the change can be quantified by the change in position of alignment marker  42  of visor base  25  relative to degree markings on plate  26  (see  FIG. 8 ). 
     C. Options and Alternatives 
     The invention may take many forms and embodiments. The foregoing examples are but a few of those. To give some sense of some options and alternatives, a few examples are given below. 
     It is of note that LEDs  22  may differ from those described herein in a number of ways and not depart from at least some aspects of the present invention. For example, other models of LEDs, or other solid state sources, may be used. As another example, subassembly  20  may include more or fewer LEDs than illustrated. As another example, LEDs  22  may be placed in an offset pattern on circuit board  21 . As another example, colored LEDs may be used. Likewise, reflector  24  and visor  41  may differ from those described herein. For example, reflector  24  may be larger or smaller or may have notch  46  omitted from the design; as has been stated, a combination of reflector designs may be used in the same fixture. As another example, visor  41  may be steeper or more shallow than illustrated. 
     As another example, fixture components may differ in composition. For example, rather than formed polymer with surfaces that are metallized, visor  41  and reflector  24  may comprise formed and polished aluminum. 
     It is of note that, as previously stated, a composite beam may comprise any number of individual beams each of which may be adjustable in terms of shape, size, intensity, aiming and/or orientation relative to the fixture, or otherwise. Further, any combination of various types and designs of optical elements (i.e., LED, visor, and reflector) may be used in subassembly  20  to achieve a desired composite beam. 
     As another option, the portion of fixture  10  housing power regulating devices (see the lower housing portion of  FIG. 2  containing panel  13 ) may be thermally isolated from the portion of fixture  10  housing subassembly  20  (see the upper housing portion of  FIG. 2  containing lens  15 ), or may be remotely located (e.g., in a separate enclosure affixed to pole  11 ). This may be done for a variety of reasons; particularly, to prevent heat emitted from LEDs  22  from damaging said devices, or to allow easy access to said devices for servicing or otherwise.