Patent Publication Number: US-8109659-B2

Title: Lighting fixture for an architectural surface structure

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Application No. 61/044,118, filed on Apr. 11, 2008. 
    
    
     FIELD OF THE DISCLOSURE 
     The present disclosure relates to lighting systems and fixtures adapted for use with architectural surface structures, and more particularly to lighting systems and fixtures that are attached to surrounding architectural structure and facilitate insertion and removal of light panels. 
     BACKGROUND OF THE DISCLOSURE 
     Various types of structures are used to create interior and exterior architectural surfaces, such as walls, ceilings, and floors. Examples of commonly-used construction materials are drywall, thee coat plaster, veneer coat plaster, concrete, stucco, plywood, siding, and wood veneer, among others. Drywall, for example, is a commonly-used construction material that provides an inexpensive yet robust option for constructing walls and ceilings. Large sheets of drywall can be cut and arranged to fit a wide variety of shapes. Gaps can be created by removing a portion from the drywall sheets so that features such as doors, windows, electrical outlets or other desired elements can be provided on the architectural surface. These gaps may be created before or after the drywall sheets are fixed in place. Shaped and cut drywall sheets are generally installed in an internal space by first securing the sheets to a wooden or steel frame. The individual wooden or steel beams that make up the frame are commonly referred to as studs. Once the drywall sheets are secured to the studs, a subsequent installation step includes applying a drywall compound to the seams and corners of the drywall sheets and to any screws and other fasteners used to secure the drywall sheets to the studs. The drywall compound hides any dents or seams in a drywall sheet so as to provide a substantially smooth surface. Typically, a corner bead made from metal or plastic is applied to outside corners before the drywall compound is applied, so as to reinforce the corners and ensure straight corner edges. 
     The design of architectural surfaces increasingly includes light features for decorative or functional purposes. Recessed lighting, for example, is commonly employed to provide a desired lighting effect. With recessed lighting, the majority of a lighting system is disposed substantially behind or recessed into an architectural surface or feature (such as a soffit). The lighting system typically includes a housing, a light source, such as an incandescent, fluorescent or halogen bulb, and some means for electrically connecting the fixture to a source of operating power. With new construction, the fixture is typically supported by hangers attached to joists. When remodeling, the fixture may be inserted through an aperture formed in an existing surface and attached to the surface material, such that the aperture provides a path for light generated by the light source. 
     More recently, the options for functional and decorative lighting designs has increased with the advent of newer light sources, such as LEDs, video panels, and other image forming devices. Accordingly, light sources are being incorporated into architectural surfaces in a variety of news ways. Often, the architectural surface is formed with gaps into which light sources are placed. The gaps may have various shapes, such as linear strips, arcuate curves, or other geometric profiles. One or more light sources are inserted into the gaps to provide the desired lighting effect. 
     Various fixtures have been proposed to secure the light sources to the architectural surfaces. Typically, these fixtures have a relatively large depth profile that necessitates excessive clearance space behind the ceiling, wall, or floor surface. Additionally, such lighting fixtures and systems are overly difficult to install, whether being used in new construction or in remodeling or renovation of existing dwellings. For example, it may be necessary to reframe a wall to add sufficient depth for the lighting fixture, which may also require cutting and reframing window sills, headers, and other architectural features for structural continuity. Conventional fixtures may be thicker than typical wall cavities and therefore require extra framing sizes. The overly bulky conventional fixtures may further interfere with other systems such as HVAC ducts, plumbing pipes, and electrical conduit runs, thereby requiring additional care when planning system layout and coordinating field installation. It is also difficult to insert and/or remove the light source from such conventional fixtures. Still further, conventional fixtures suffer from socket shadow, where light sources arranged end-to-end create light variations on the lens or louver of the fixture. 
     SUMMARY OF THE DESCRIPTION 
     A lighting fixture is disclosed for attachment to an architectural surface structure and adapted to hold a light source. The lighting fixture includes a base plate, and first and second mounting brackets. Each mounting bracket includes a rear panel coupled to the base plate and a front panel joined to the rear panel by a side wall to define a receptacle between the front panel and the base plate, the receptacle having a depth defined by a spacing distance between the front panel and the base plate sufficient to receive an edge of the light source, each front panel further defining an inner terminal edge, the first and second mounting brackets being oriented such that the receptacles diametrically oppose one another, the first and second mounting brackets further being positioned such that the front panel inner terminal edges are laterally spaced from one another to define a lighting opening. A first clamp is disposed in the first mounting bracket receptacle, the first clamp including a base end coupled to the base plate, a grip portion configured to engage the light source, and a spring section disposed between the base end and the grip portion and sized to receive a first edge of the light source, the spring section being configured to bias the first edge of the light source toward the base plate. A second clamp is disposed in the second mount bracket receptacle, the second clamp including a base end coupled to the base plate, a grip portion configured to engage the light source, and a spring section disposed between the base end and the grip portion and sized to receive a second edge of the light source, the spring section being configured to bias the first edge of the light source toward the base plate. 
     An alternative lighting fixture is disclosed for attachment to an architectural surface structure and adapted to hold a light source. The lighting fixture comprises a base plate and first and second mounting brackets. Each mounting bracket includes a rear panel coupled to the base plate and a front panel joined to the rear panel by a side wall to define a receptacle between the front panel and the base plate, the receptacle having a depth defined by a spacing distance between the front panel and the base plate sufficient to receive an edge of the light source, each front panel further defining an inner terminal edge, the first and second mounting brackets being oriented such that the receptacles diametrically oppose one another, the first and second mounting brackets further being positioned such that the front panel inner terminal edges are laterally spaced from one another to define a lighting opening. A first clamp has a base end coupled to the first mounting bracket rear panel and a spring configured to extend at least partially toward the first mounting bracket front panel, thereby to generate a biasing force directed toward the first mounting bracket front panel. A second clamp has a base end coupled to the second mounting bracket rear panel and a spring configured to extend at least partially toward the second mounting bracket front panel, thereby to generate a biasing force directed toward the second mounting bracket front panel. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a more complete understanding of the disclosed methods and apparatuses, reference should be made to the embodiment illustrated in greater detail on the accompanying drawings, wherein: 
         FIG. 1  is a schematic illustration of a room incorporating various types of lighting systems according to the present disclosure. 
         FIG. 2  is a perspective view of a lighting fixture constructed according to the present disclosure. 
         FIG. 3  is a cross-sectional view of the lighting fixture taken along line  3 - 3  of  FIG. 2 . 
         FIG. 4  is an enlarged cross-sectional view of a bracket and clamp used in the lighting fixture of  FIG. 2 . 
         FIG. 5  is an enlarged perspective view of a clamp used in the lighting fixture of  FIG. 2 . 
         FIG. 6A  is a side elevation view illustrating one end of a light panel inserted into a bracket of a lighting fixture. 
         FIG. 6B  is a side elevation view illustrating both ends of a light panel inserted into the brackets of a lighting fixture. 
         FIG. 7  is a cross-sectional view of an alternative embodiment of lighting fixture configured for use in a remodeling process. 
         FIG. 8  is a cross-sectional view of a further alternative embodiment of a lighting system configured for use along an outer periphery of an architectural surface. 
         FIG. 9  is a perspective view of an alternative lighting fixture. 
         FIG. 10  is a side elevation view, in cross-section, of the lighting fixture of  FIG. 9  with installed light source and filter. 
         FIG. 11  is an enlarged plan view of a bracket used in the lighting system of  FIG. 9 . 
         FIG. 12  is an enlarged perspective view of a clamp used in the lighting system of  FIG. 9 . 
         FIG. 13  is a side elevation view, in cross-section, of a light source being installed into the lighting system of  FIG. 9 . 
         FIG. 14  is a side elevation view, in cross-section, of a further embodiment of a lighting system. 
         FIG. 15  is an enlarged perspective view of a clamp used in the lighting system of  FIG. 14 . 
         FIG. 16  is a side elevation view, in cross-section, of a light source being installed into the lighting system of  FIG. 14 . 
         FIG. 17  is a side elevation view of the lighting system of  FIG. 14  with an alternative lens. 
         FIG. 18  is a side elevation view, in cross-section, of an alternative embodiment of a lighting system for an outside corner of an architectural structure. 
         FIG. 19  is a side elevation view, in cross-section, of a lighting system for an inside corner of an architectural structure. 
         FIG. 20  is a perspective view of a lighting system having mitered corners. 
     
    
    
     It should be understood that the drawings are not necessarily to scale and that the disclosed embodiments are sometimes illustrated diagrammatically and in partial views. In certain instances, details which are not necessary for an understanding of the disclosed methods and apparatuses or which render other details difficult to perceive may have been omitted. It should be understood, of course, that this disclosure is not limited to the particular embodiments illustrated herein. 
     DETAILED DESCRIPTION OF THE DISCLOSURE 
     Various embodiments of a lighting fixture adapted for attachment to an architectural surface structure and configured to hold a light source are disclosed herein. The lighting fixture facilitates introduction of lighting design elements by providing a structure that is easily incorporated into commonly used architectural surface structures. The disclosed lighting fixtures further accommodate different sizes of light sources. Light sources may be quickly and easily inserted into and removed from the lighting fixture. According to certain features disclosed herein, the lighting fixture may include spring arms and bearing structures to automatically center the light source in the fixture. The bearing structures may also be configured to support a portion of the light source as it is assembled with the lighting fixture, thereby making it easier to install and remove the light source. While the lighting fixture is described herein for use in an interior wall, it will be appreciated that the lighting fixture may be used in any type of interior or exterior architectural surface or feature, including a wall, ceiling, floor, roof, or soffit. 
     Various embodiments of a lighting system are described below, including embodiments relating particularly to LED-based light sources. It should be appreciated, however, that the present invention is not limited to any particular manner of implementation, and that the various embodiments discussed explicitly herein are primarily for purposes of illustration. For example, the various concepts discussed herein may be suitably implemented in a variety of environments involving LED-based light sources, other types of light sources not including LEDs, environments that involve both LEDs and other types of light sources in combination, and environments that involve non-lighting-related devices alone or in combination with various types of light sources. 
     As used herein for purposes of the present disclosure, the term “LED” should be understood to include any electroluminescent diode or other type of carrier injection/junction-based system that is capable of generating radiation in response to an electric signal. Thus, the term LED includes, but is not limited to, various semiconductor-based structures that emit light in response to current, light emitting polymers, organic light emitting diodes (OLEDs), electroluminescent strips, and the like. In particular, the term LED refers to light emitting diodes of all types (including semi-conductor and organic light emitting diodes) that may be configured to generate radiation in one or more of the infrared spectrum, ultraviolet spectrum, and various portions of the visible spectrum (generally including radiation wavelengths from approximately 400 nanometers to approximately 700 nanometers). Some examples of LEDs include, but are not limited to, various types of infrared LEDs, ultraviolet LEDs, red LEDs, blue LEDs, green LEDs, yellow LEDs, amber LEDs, orange LEDs, and white LEDs. Additional LEDs include RGB, RGGB, and RGBW configurations, as well as LEDs with remote phosphor systems. It also should be appreciated that LEDs may be configured and/or controlled to generate radiation having various bandwidths (e.g., full widths at half maximum, or FWHM) for a given spectrum (e.g., narrow bandwidth, broad bandwidth), and a variety of dominant wavelengths within a given general color categorization. 
     For example, one implementation of an LED configured to generate essentially white light (e.g., a white LED) may include a number of dies which respectively emit different spectra of electroluminescence that, in combination, mix to form essentially white light. In another implementation, a white light LED may be associated with a phosphor material (positioned either at the die or remotely, such as in a snap-on lens or an intermediary lens) that converts electroluminescence having a first spectrum to a different second spectrum. In one example of this implementation, electroluminescence having a relatively short wavelength and narrow bandwidth spectrum “pumps” the phosphor material, which in turn radiates longer wavelength radiation having a somewhat broader spectrum. 
     It should also be understood that the term “LED” does not limit the physical and/or electrical package type of an LED. For example, as discussed above, an LED may refer to a single light emitting device having multiple dies that are configured to respectively emit different spectra of radiation (e.g., that may or may not be individually controllable). Also, an LED may be associated with a phosphor that is considered as an integral part of the LED (e.g., some types of white LEDs). In general, the term LED may refer to packaged LEDs, non-packaged LEDs, surface mount LEDs, chip-on-board LEDs, T-package mount LEDs, radial package LEDs, power package LEDs, LEDs including some type of encasement and/or optical element (e.g., a diffusing lens), etc. 
     The term “light source” should be understood to refer to any one or more of a variety of radiation sources, including, but not limited to, LED-based sources (including one or more LEDs as defined above), incandescent sources (e.g., filament lamps, halogen lamps), fluorescent sources, phosphorescent sources, high-intensity discharge sources (e.g., sodium vapor, mercury vapor, and metal halide lamps), lasers, other types of electroluminescent sources, pyro-luminescent sources (e.g., flames), candle-luminescent sources (e.g., gas mantles, carbon arc radiation sources), photo-luminescent sources (e.g., gaseous discharge sources), cathode luminescent sources using electronic satiation, galvano-luminescent sources, crystallo-luminescent sources, kine-luminescent sources, thermo-luminescent sources, triboluminescent sources, sonoluminescent sources, radioluminescent sources, and luminescent polymers. 
     A given light source may be configured to generate electromagnetic radiation within the visible spectrum, outside the visible spectrum, or a combination of both. Hence, the terms “light” and “radiation” are used interchangeably herein. Additionally, a light source may include as an integral component one or more filters (e.g., color filters), lenses, or other optical components. The lens may have one of many possible distributions, such as wide, narrow, asymmetric, and wall-wash, among others. The lens may be provided directly on the light source or remotely positioned, and may be provided with other components such as remote phosphor, inner or outer prisms, micro-prisms, or holographic prisms. The lens may also be a diffusion lens provided before the final surface lens. 
     Also, it should be understood that light sources may be configured for a variety of applications, including, but not limited to, indication, display, and/or illumination. An “illumination source” is a light source that is particularly configured to generate radiation having a sufficient intensity to effectively illuminate an interior or exterior space. In this context, “sufficient intensity” refers to sufficient radiant power in the visible spectrum generated in the space or environment (the unit “lumens” often is employed to represent the total light output from a light source in all directions, in terms of radiant power or “luminous flux”) to provide ambient illumination (i.e., light that may be perceived indirectly and that may be, for example, reflected off of one or more of a variety of intervening surfaces before being perceived in whole or in part). 
     The term “lighting fixture” is used herein to refer to the structure for supporting a light source. A “lighting system” would include both a lighting fixture and a light source. 
       FIG. 1  illustrates various locations and configurations of lighting systems in which the lighting fixtures disclosed herein may be used. For example, lighting systems  12 A,  12 B have light sources formed as vertically oriented, elongate strips extending fully or partially along a single wall  10 A. Lighting system  12 C has a light source that extends along both the wall  10 A and a ceiling  11 . Lighting system  12 D has a light source that extends along a single wall  10 B in a pattern that includes a right angle  14 A and an obtuse angle  14 B. Lighting system  12 E has a light source disposed in a single wall  12 B and formed in a closed polygon shape such as a rectangle. Lighting system  12 F has a light source disposed in the wall  12 B and extending as a substantially horizontally oriented strip with a slanted end  15 . Lighting system  12 G has a light source that is a vertically oriented, elongate strip that spans an inside corner formed between two walls  12 B and  12 C. Lighting system  12 H has a light source that extends substantially horizontally over three walls  12 B,  12 C, and  12 D and includes an inner corner  16 A and an outer corner  16 B. Lighting system  121  has a light source that is a vertically oriented, elongate strip that spans an outside corner formed between two walls  12 C and  12 D. Lighting system  12 J has a light source disposed in a single wall  12 D and formed in a relatively small geometric shape such as a square. Lighting system  12 K has a light source that forms a border along a perimeter of a wall  10 E. Lighting system  12 L has a light source that is disposed in the ceiling  11  and is formed as an elongate strip. In addition to the illustrated embodiments, the lighting system may also be partially or completely disposed in a floor  13 . The foregoing merely provides examples of the various shapes and patterns in which the lighting systems may be provided, and is not intended to be exhaustive. In that regard, combinations or further modifications of the foregoing examples may be employed. For example, the lighting system may have a light source that traverses an acute, rather than obtuse, angle, is formed in “open” or “non-polygon” patterns, or has multiple legs of varying length and/or width. 
     As shown in  FIGS. 2 and 3 , a lighting fixture  20  is coupled to an architectural surface structure such as a wall  22 . The wall  22  may be constructed from any material. In the illustrated embodiment, a gap  24  is formed in the wall  22  and is bordered by wall portions  22 A,  22 B. The gap  24  may have virtually any shape including, but not limited to, a rectangle, polygon, curve, oval, or circle. In an exemplary embodiment, the wall  22  is constructed from one or more drywall sheets arranged on a conventional stud frame, and the gap  24  is created by removing a portion or portions from the one or more drywall sheets. Alternatively, the lighting fixture  20  may first be installed on the studs and the wall may be added later. In other embodiments, the wall  22  may be constructed of wallboard, lathing for plaster, wood, or any other material used to construct an architectural surface. 
     The lighting fixture  20  includes a base plate  30  that forms a rear or base of the fixture. In the illustrated embodiment, the base plate  30  spans a longitudinal length of the fixture and extends in opposite lateral directions to partially overlie the wall portions  22 A,  22 B. The base plate  30  may include pre-drilled holes  32  sized to accept fasteners for attaching the base plate  30  to the wall  22 . The base plate  30  is preferably constructed of a material suitable for supporting the components of the lighting fixture  20  and the light source. It is further preferable to use material that can act as a heat sink to maintain the thermal performance of the light source. Two exemplary materials exhibiting these properties are sheet metal and aluminum. The base plate  30  may further include heat fins projecting rearward to improve heat dissipation. Additionally, the base plate  30  may be coated with an intumescent paint to provide a fire-rated assembly to meet construction and/or fire code requirements. The intumescent coating can be applied on the front surface, rear surface, or both the front and rear surfaces of the base plate  30 . The base plate  30  further may be formed without holes for applications requiring air tight construction, thereby to stop airflow from conditioned to unconditioned spaces. 
     First and second mounting brackets  34 A,  34 B are coupled to the base plate  30 . Each mounting bracket  34 A,  34 B includes a front panel  36 , a side wall  38 , and a rear panel  40  ( FIG. 3 ). An exterior surface  37  of the front panel  36  may be formed with grooves  39  for receiving drywall compound, plaster, or similar material commonly applied to architectural surfaces. An inner terminal edge  42  of the front panel  36  may include a lip  44  which defines a suitable depth for the drywall compound over the front panel  36 , thereby to conceal the mounting brackets  34 A,  34 B. While the inner terminal edges  42  are illustrated in  FIG. 3  as being substantially linear and oriented parallel to one another, it will be appreciated that the edges  42  may have a curved or otherwise non-linear shape and may be oriented non-parallel with respect to each other. An outer terminal edge  46  of the front panel partially overlies an associated wall portion  22 A,  22 B. The portion of the front panel  36  located near the outer terminal edge  46  may gradually thin so that a front surface slopes toward the wall  22 , thereby to facilitate a substantially continuous appearance once mud or plaster is applied. The front surfaces of the front panels  36  may further include grooves  39  for improving adherence of mud or plaster thereto. The grooves may be spaced in a particular pattern that indicates to the installer where screws may be used to attach the brackets  34 A,  34 B to the wall  22 . 
     While the base plate  30  and brackets  34 A,  34 B are illustrated in  FIG. 3  as separate components that are assembled together, it will be appreciated that these elements may be formed together as a unitary structure. 
     The side wall  38  is configured to create sufficient spacing between the front and rear panels  36 ,  40  to receive a light source and between the front panel  36  and base plate  30  to receive the wall  22 , as best shown in  FIGS. 3 and 7 . The inwardly extending portion of the front panel  36  and the base plate  30  form an edge receptacle  50 . The front panel  36  and base plate  30  are separated by a spacing distance D so that the edge receptacle  50  has a depth sufficient to receive the light source. The outwardly extending portions of the front panel  36  and base plate  30  form an exterior socket  52  having a depth sufficient to receive a portion of the wall  22 . As a result, the fixture  20  may have a thickness that is substantially the same as the wall  22 , and therefore the fixture  20  may be installed without requiring reframing or other considerations associated with thicker, conventional light fixtures. 
     A bearing structure  60  may be formed on an interior surface  62  of the front panel  36  to assist with insertion of the light source into the lighting fixture  20  and to center the light source within the lighting fixture  20 . As best shown in  FIGS. 3 ,  4 , and  6 A, the bearing structure  60  is illustrated as having an inclined bearing structure profile, with a base end  64  located nearer the inner terminal edge  42  of the front panel  36  and a projection end  66 . The bearing structure  60  is configured to extend gradually farther into the edge receptacle  50  from the base end  64  to the projection end  66 . In the illustrated embodiment, the bearing structure  60  defines an inclined surface  68  extending between the base and projection ends  64 ,  66 . 
     The inclined bearing structure  60  described herein may assist with centering the light source within the lighting fixture  20 . When the light source is biased into contact with the bearing structure  60  (as understood more fully below), the inclined surface  68  urges the engaged edge of the light source toward a center of the fixture  20 . In addition, the bearing structure  60  provides a support for holding an edge of the light source during installation. As best understood in the context of a horizontally extending light system, a bottom edge of the light source may first be inserted into the edge receptacle  50  formed by the lower mounting bracket  34 . The bearing structure  60  projects into the receptacle  50  to engage and support the lower edge of the light source, thereby preventing it from sliding too far into the mounting bracket  34 . As a result, the bearing structure  60  assists with installation of the light source. It will be appreciated that the bearing structure  60  may be provided in alternative configurations, such as a corner, step, rounded/curved edge, or other abutment surface. Some of these alternative configurations may provide only one of the centering and edge support functions. 
     A slot  70  ( FIG. 3 ) may also be formed on the interior surface  62  of the front panel  36  to receive a tab  72 . The slot  70  and tab  72  allow multiple mounting brackets to be quickly and easily aligned, if needed. 
     The first and second mounting brackets  34 A,  34 B are oriented on the base plate  30  so that their respective edge receptacles  50  diametrically oppose each other, as illustrated in  FIGS. 1 and 2 . The mounting brackets  34 A,  34 B are further positioned on the base plate  30  so that their respective front panel inner terminal edges  42  are laterally spaced from one another. A lighting gap  74  spans the distance between the inner terminal edges  42  through which the light source will direct light. 
     An end cap  76  may be provided at the longitudinal ends of the fixture  20 . As best shown in  FIGS. 3 and 4 , the mounting bracket side walls  38  may be configured with a fastener socket  77  for receiving a fastener  78 , thereby to secure the end cap  76  to the brackets  34 A,  34 B. 
     The lighting fixture  30  further includes one or more clamps  80  coupled to each mounting bracket  34 A,  34 B for holding a light source in the fixture. As used herein, the term “coupled” includes components that are either directly attached or attached through one or more intermediate components. As best shown in  FIGS. 4 and 5 , each clamp  80  is generally provided as a leaf spring. Accordingly, each clamp  80  includes a base end  82  coupled to the mounting bracket  34 . In the illustrated embodiment, the base end  82  includes inner and outer tabs  84 A,  84 B configured to closely fit over the mounting bracket rear panel  40 . A spring end  86  is provided opposite the base end  82 . The spring end  86  is preferably aligned with the lighting gap  74  and configured to apply a biasing force in the direction of the mounting bracket front panel  36 . To obtain the desired biasing force, an aperture  88  may be formed in the spring end  86 . Each clamp  80  may further include a stop  90  extending into the edge receptacle  50  and sized to reliably engage an edge of the light source as it is inserted the mounting bracket  34 , thereby to prevent the light source from sliding too far into the receptacle  50 . 
     Still further, each clamp  80  may include a spring arm  92  for providing additional biasing force and for centering the light source within the fixture  20 . As best shown in  FIG. 4 , the spring arm  92  extends at an oblique angle a from a body of the clamp  80 . Accordingly, the spring arm  92  applies a biasing force directed not only toward the front panel  40  but also toward a center of the fixture  20 . The light source, when engaged at opposite lateral portions by such spring arms  92 , is automatically centered with respect to the lighting gap  74 . 
     A sufficient number of clamps are coupled to each bracket  34  to ensure that the light source is securely retained within the lighting fixture  20 . In the embodiment illustrated in  FIG. 2 , a single clamp  80  is attached to each bracket  34 A,  34 B. In other embodiments, however, more than one clamp  80  may be attached to each bracket  34 A,  34 B. Various factors, such as the longitudinal length of the fixture  20 , size and weight of the light source, size of the lighting gap, and orientation of the lighting system (i.e., extending horizontally or vertically along a wall, extending across a ceiling, etc.), should be considered when selecting the number of clamps  80  to use. 
     While the spring end  86 , stop  90 , and spring arm  92  are described above as integrally provided in a single clamp  80 , it will be appreciated that these components may be provided as separate structures. 
     An alternative embodiment of a lighting fixture  120  is illustrated in  FIG. 7  that is particularly suited for renovation or remodeling projects. The lighting fixture  120  is substantially similar to the lighting fixture  20  described above, but has a modified base plate  130 . More specifically, the lateral edges of the base plate  130  do not extend outwardly to overlie portions of the wall  22  but instead terminate at the mounting bracket side wall  38 . This allows the assembled lighting fixture  120  to be inserted into the wall  22  from the front without requiring access to the space behind the wall  22 . In this embodiment, fasteners may be used to attach the mounting bracket front panel  36  to the exterior surface of the wall  22 . The fasteners may be concealed by applying drywall compound over the front panel  36 . 
     The lighting fixtures described herein allow light sources to be quickly and easily inserted and removed. As shown in  FIGS. 6A and 6B , a light source such as an LED light panel  100  may be provided having lateral edges  102 A,  102 B sized for insertion into the fixture  20 . In the illustrated embodiment, the LED light panel has a substantially rectangular cross-section and is configured as an elongate strip. As noted above, the lighting fixtures may be used with light sources having other configurations and/or cross-sections. The light source may further have other distributions from spot to flood or lambertian, as well as asymmetric for wall wash applications. 
       FIGS. 6A and 6B  also illustrate how a light panel  100  may be installed into a lighting fixture, such as the lighting fixture  20 . A first edge  102 B of the light panel  100  may be inserted into the edge receptacle  50  defined by mounting bracket  34 B. The light panel edge  102 B is advanced until it engages the stop  90 . During this step, the bearing structure  60  may guide the edge  102 B toward the clamp  80  to ensure that it engages the stop  90 . The edge receptacle  50  is sized and the stop  90  is located such that, with the first edge  102 B fully inserted, the second edge  102 A of the light panel has clearance to be rotated into alignment with the edge receptacle  50  of the other mounting bracket  34 A. The light panel  100  may then be repositioned so that the edge  102 A is inserted into the edge receptacle  50  of the mounting bracket  34 A. When the user subsequently releases the light panel  100 , the spring arms  92  and bearing structures  60  engage the opposite edges  102 A,  102 B to secure the light panel  100  in place. The spring arms  92  and bearing structure  60  may also bias the light panel  100  to a centered position with respect to the lighting gap  74 , as illustrated in  FIG. 6B . 
     The lighting systems described herein also allow components in addition to the light source to be inserted into the edge receptacles  50 . For example, a filter, lens, or other optical component may be needed to achieve a desired lighting effect. In the embodiment illustrated in  FIGS. 2-5 , the lens may be slid in place, while other embodiments may use snap-in or other types of lenses. The lens may be colored or configured to produce a desired light distribution, such as spot, flood, or asymmetric. Such components may be formed of relatively thin layers of paper, acrylic ribbon, or other material. These components may be simply and easily assembled with the lighting fixture by positioning them as desired over the light source and inserting them in the same manner as the light source, either individually or in combination with the light source. The clamps  80  will provide a sufficient biasing force to retain the additional components in the desired position. 
     The ease with which components are inserted into and removed from the mounting brackets  34  allows a temporary support member to be used as the lighting fixture is attached to the architectural surface. The temporary support member may be sized and configured to closely fit within the edge receptacles  50 , and may be formed of a durable material such as cardboard or wood. Prior to attachment to the architectural surface, the temporary support member may be inserted into the edge receptacles  50 . The support member prevents drywall compound, plaster, or other construction materials from entering the fixture and provides additional resistance against bending or other undesirable forces as the lighting fixture is manipulated into place and attached to the architectural surface. Once the lighting fixture is in place, the temporary support panel is removed and the light source may be inserted. 
     If needed, a driver, power supply, or current control ballast  94  ( FIG. 7 ) may be provided to power the light source. In the illustrated embodiment, the ballast  94  is disposed in a housing that is attached to a rear of the base plate  130 . The housing may be positioned to occupy unused space behind the architectural surface, such as the space between adjacent studs. Alternatively, the housing may be positioned remotely from the base plate  130 . 
     The mounting brackets  34 A,  34 B may be further configured to provide a wireway for the light source. As best shown in  FIG. 6B , each mounting bracket  34  includes a side space  96  sized to receive one or more wires or connectors for connecting the light source to a power source. Accordingly, the wiring may be located laterally next to the light source rather than behind the light source, thereby helping to maintain the relatively small thickness of the fixture. The side space  96  may be provided on either or both mounting brackets  34 A,  34 B as needed. 
     While the brackets  34 A,  34 B may be configured to provide the wireway as noted above, the space provided behind the front panels  36  may be used for alternative or additional purposes. For example, the front panels  36  may intentionally overlap the edges of the light source  100  by a desired distance to conceal the peripheral edges of the light source  100 . The edges of many light panels may be less bright or may create scallop patterns. The front panels  36  may extend over these areas so that the visible light is more uniform. If, however, a light source is used that generates uniform light entirely to its edges, then the front panels need not extend over the edges of the light source and the light source may have the same width as the aperture between the inner terminal edges of the front panels. 
     A further embodiment of a lighting fixture  220  is illustrated in  FIG. 8 . The lighting fixture  220  is particularly suited for use along a periphery of an architectural surface, such as the lighting system  12 K illustrated in  FIG. 1 . The periphery of an architectural surface is often bordered by another surface that extends along a different plane. In certain applications, therefore, one side of the lighting fixture may have limited available space in which to extend. 
     The lighting fixture  220  addresses the limited available space issue by providing a low profile mounting bracket  234 A. The mounting bracket  234 A includes a front panel  236 , a side wall  238 , and a rear panel  240 . Unlike the previous exemplary embodiments, the front panel  236  does not extend outwardly but instead terminates at the side wall  238 . The lighting fixture  220  also includes a back plate  230  that terminates at the side wall  238  of the mounting bracket  234 A and a clamp  280 A modified to fit the mounting bracket  234 A. The other mounting bracket  234 B and clamp  280 B may be provided substantially identical to those described above. 
     An alternative lighting system  300  is illustrated in  FIGS. 9-13  in which a light source  301  is biased toward a base plate  302 . The system  300  is coupled to an architectural structure such as a wall  304 , and includes mounting brackets  306 A,  306 B and clamps  308  that are different from the previous embodiments. 
     Each mounting bracket  306 A,  306 B includes a front panel  310 , a side wall  312 , and a rear panel  314  ( FIG. 11 ). An inner terminal edge  316  of the front panel  310  may include a lip  318  which defines a suitable depth at which drywall compound or plaster may be applied over the front panel  310 . The front panel  310  further has an outer terminal edge  320 . A front surface  322  of the front panel  310  may gradually taper rearward so that the thickness of the front panel  310  is greater at the inner terminal edge  316  than at the outer terminal edge  320 , as best shown in  FIG. 11 . Grooves  324  may be formed in the front surface  322  to improve adherence of the drywall compound or plaster to the front panel  310 . The rear panel  314  is coupled to the base plate  302 , and the side wall  312  is sized to create sufficient spacing between the front and rear panels  310 ,  314  to receive light source  301 . The rear panel  314  may also define a wireway space  326  for accommodating electrical wires  328  connected to the light source  301 . An arm  330  extends from a rear surface of the front panel  310  to define a recess  332 . A second recess  334  is located between the front panel  310  and a portion of the side wall  312 . The first and second recesses  332 ,  334  are aligned and sized to receive edges of a tab (not shown) used to connect adjacent mounting brackets, if needed. 
     Multiple clamps  308  may be coupled to the base plate  302  for securing the light source  301  in place. As best shown in  FIG. 12 , each clamp  308  may include a base end  340  adapted for attachment to the base plate  302 . A spring section  342  of the clamp  302  may be arcuate and sized to receive an edge of the light source  301 . A grip portion  344  is configured to engage a surface of the light source  301 , and the spring section  342  may be configured to apply a biasing force toward the base plate  302  when the light source  301  is inserted, as best shown in  FIG. 10 . A clip section  346  is provided to engage a portion of a lens, cover, or other optional structure inserted over the light source, as understood more fully below. The clip section  346  may be angled as shown to provide a biasing force toward the front panel  310 , as well as to accommodate various thicknesses of the optional overlying structure. As shown in  FIG. 9 , multiple clamps  308  may be spaced along the base plate  302  to secure the light source  301  in place. 
     An overlying structure, such as a lens  350 , is shown in  FIG. 10 . The lens  350  includes a main panel  352  and opposed, flexible side walls  354 . Each side wall  354  includes a projection  356 . During installation, the side walls  354  may be flexed inwardly so that the projections  356  may slide past the inner terminal edges  316  of the bracket front panels  310 . Once the projections  356  are past the terminal edges  316 , they may resume an at least partially expanded state to retain the lens  350  within the brackets  306 A,  306 B. The clamp clip sections  346  may also engage a portion of the side walls  354  to further secure the lens  350  in place. Portions of the lens side walls  354  and projections  356  may be cut away to facilitate rolling of the lens for shipping long pieces, or to allow various lens intersections. 
     Installation of the light source  301  into the brackets  306 A,  306 B is best illustrated with reference to  FIG. 13 . A first lateral edge of the light source  301  may be inserted into one of the clamps  308 . The opposite lateral edge of the light source  301  may then be rotated past the bracket  306 B until it is adjacent the base plate  302  and aligned with the other clamp  308 . The light source  301  may then be laterally translated so that both clamps  308  engage and hold the light source  301  in place. By holding the light source  301  against the back plate  302 , the lighting system  300  advantageously increases the amount of heat dissipated through the base plate  302 . 
     The lens  350  may then be snap-fit into place as shown in  FIG. 10 , with the projections  356  pinched between the clamp clip section  346  and a rear surface of the front panel  310 . An outer surface  358  of the lens  350  may be substantially flush with the wall  22  to provide a clean, continuous transition between the wall and light system. 
     The lens  350  illustrated in  FIG. 10  may be of any style and type known in the art. The lens  350  may include an accessory filter (such as a decorative stencil, a color gel, or other diffusing media) disposed behind the outer surface  358 . The lens  350  may include inwardly extending flanges  355  to hold such lens accessories in place. The lens  350  further may be formed with various profiles to obtain asymmetric or different distributions and brightness. The side walls  354  may include an extended, inwardly projecting lip  357  to provide additional diffusion, thereby avoiding hot spots and/or scallops that may emanate from the light source  301 , which may be a particular issue with some LEDs. The lens  350  may be cut and mitered in the field for precise fit and finish. The side walls  354  further may be oriented at a slight angle as shown to permit insertion of a tool such as a putty knife between the lens  350  and brackets  306 A,  306 B, thereby to retract the projections  356  to facilitate removal of the lens  350 . 
     A further alternative embodiment of a lighting system  400  is illustrated in  FIGS. 14-16 . The lighting system  400  is substantially similar to the system  300  discussed above, but uses a different clamp  402 . As best shown in  FIG. 15 , each clamp  402  may include a base end  404  adapted for attachment to a base plate  403 . A spring section  404  of the clamp  402  may be arcuate and sized to receive an edge of the light source  401 . A grip portion  406  is configured to engage a surface of a light source  408 , and the spring section  342  may be configured to apply a biasing force toward the base plate  403  when the light source  401  is inserted, as best shown in  FIG. 16 . A centering nub  410  is disposed between the spring section  404  and the grip portion  406 . The centering nub  410  projects rearward toward the base plate  403  to provide a biasing force that centers the light source  401  with respect to a gap  412  defined between brackets  414 A,  414 B. A clip section  416  is provided to engage a portion of a lens, cover, or other optional structure inserted over the light source.  FIG. 14  illustrates a snap-fit lens  418 , identical to the lens  350  described above, held securely in place between the clip sections  416  of the clamps  402  and the brackets  414 A,  414 B.  FIG. 14  also illustrates a cover layer  420  of material, such as drywall compound or plaster, applied over the brackets  414 A,  414 B and wall  22  to provide a continuous transition. Lips  422  extending outwardly from the brackets  414 A,  414 B provide a reference depth at which the cover layer  420  may be applied. 
       FIG. 17  illustrates a lighting system  500  nearly identical to the system  400  of  FIGS. 14-16 , except with an alternative lens  502 . Instead of having flexible side walls, the lens  502  is a planar sheet of material having a thickness sufficient to be pinched between clamps  504  and brackets  506 A,  506 B. 
       FIG. 18  illustrates a lighting system  600  having an outer corner bracket  602 , which may be suitable for use on an architectural structure forming an outside edge. The system  600  includes the clamps  402  and one bracket  34 B as described above. The outer corner bracket  602 , however, may join wall sections that extend at an angle to one another, such as perpendicular wall sections  22   a ,  22   b  shown in  FIG. 18 . In the illustrated embodiment, the outer corner bracket  602  includes a first front panel  604 , a second front panel  606 , and an intermediate panel  608 . The intermediate panel  608  may be coupled to a base plate  610 . The first front panel  604  may include a lip  612 . A corner bead  614  may extend outwardly from the corner formed between the first and second front panels  604 ,  606 . The lip  612  and corner bead  614  provide a reference depth at which drywall compound or plaster may be applied over the bracket  602 . 
       FIG. 19  illustrates a lighting system  700  having an inner corner bracket  702  adapted for use at an inside edge of an architectural structure. The system  700  includes clamps  402  and one bracket  34 B as described above. The corner bracket  702 , however, is modified for attachment to a wall  23  that is not substantially planar with the wall  22  to which the bracket  34 B is attached. In the illustrated embodiment, wall  23  is substantially perpendicular to the wall  22  to form an inside corner. The corner bracket  702  includes a base wall  704  coupled to a base plate  706 , an intermediate wall  708 , and a front panel  710  coupled to the wall  23 . The intermediate wall  710  may include a lip  712  providing a reference depth for a cover layer of material (not shown). 
       FIG. 20  illustrates a further alternative embodiment of a lighting system  800 . The lighting system  800  includes a closed end  802  formed by mitered brackets  803 ,  804 , and  806 . A closed end may be used when an end of the fixture terminates at a central part of the wall (such as light system  12 A in  FIG. 1 ) rather than at a wall edge (such as light system  12 B in  FIG. 1 ). The lighting system  800  further includes an open end  810  adapted for connection to an additional portion of the lighting system  800  (not shown). The open end  810  includes brackets  812 ,  814  that are positioned to mate with components on the other fixture piece (not shown). The brackets  812 ,  814  may be mounted on a common base plate  816  prior to reaching the installation site, thereby minimizing expensive field adjustments. This is particularly advantageous for more complex shaped lighting systems, such as lighting system  12 E shown in  FIG. 1 . 
     While the lighting fixture has been illustrated for use in walls or ceilings, it may also be used in various other structures. For example, the lighting fixture may be used in floors, stairs, interior cabs, risers, under cabinets, showers, behind glass tiles, and behind mirror lights, among other locations. Use in a floor requires additional considerations, such as a waterproof barrier for the light source. As noted above, however, the lighting fixtures disclosed herein permit quick and easy insertion of additional components, and therefore are well suited for flooring applications. Furthermore, the mounting brackets, such as brackets  34 A,  34 B, may be modified to have taller lips  44  to accommodate the thicker materials typically used to create floor surfaces. 
     While only certain embodiments have been set forth, alternatives and modifications will be apparent from the above description to those skilled in the art. These and other alternatives are considered equivalents and within the spirit and scope of this disclosure and the appended claims.