text: turning now to the drawings , fig1 shows an embodiment of a reduced shadow system for illuminating an activity area 20 . this system for substantially reducing shadow and glare while providing even illumination levels within the designated area can be applied to an entire room or to modules ( e . g . 40 ft .× 40 ft .) within a large room or un - divided building such as a warehouse , barn , garage , or factory . a light source 22 of any type may be located near the center of the activity area 24 to be illuminated . the light source 22 may use an electrically powered lamp 26 such as a high pressure sodium or metal halide bulb . in other embodiments , the light source 22 could be made using a light pipe , optical fiber , arc lamp , flame , mantle , laser , light emitting diode , or other means for introducing natural or artificial light for illumination , each of which and their equivalents is deemed equivalent to an electrically powered lamp 26 . the light source 22 is equipped with an upper reflector 28 and a lower reflector 30 designed to enhance radial light emission . lenses or prisms may also be used either together with , or in place of the upper source reflector 28 and lower source reflector 30 to minimize losses and to confine light to the radial plane generally parallel to the floor 32 of the activity area 24 . it is also possible to configure the upper source reflector 28 and the lower source reflector 30 , together with any lenses or prisms so that light emanating from the source describes a hollow conical pattern rather than a flat disk pattern . in that way , it would be possible to mount the source 22 at an elevation different from the elevation of the perimeter reflectors 34 . paths of light emanating from the source 22 are shown by dashed lines terminating with arrow points . it is axiomatic that the angle of reflection from a flat reflecting surface or the tangent to a curved reflecting surface is the same as the angle of incidence under most circumstances . any apparent deviation from the fundamental laws of physics and optics in the illustrated light paths is unintentional , and all assertions regarding the behavior of light and materials made in this disclosure are to be construed so as to conform with those physical and chemical laws published in the crc handbook of chemistry and physics , 47 th edition , and such other treatises as may have equivalent authority among engineers , physicists , and other professionals active in the fields of optics and lighting design . the light source 22 is normally installed near the ceiling of the structure , but preferably below any roof trusses or other obstructions that would absorb light . perimeter reflectors 34 are installed at or near the upper part of the walls 36 , below structural elements , mechanical installations , and preferably near the elevation of the light source 22 . the perimeter reflectors 34 may have a reflective face surface , a transparent face surface with a reflective backing , a coated reflective face surface , or may be made of one or more refractive elements such as prisms , and could be made from sheet stock having a multiplicity of prisms formed on one or more surfaces . most of the light from the source 22 is focused on the perimeter reflectors 34 . however , some of the light from the central source 22 may be directed downwardly through light transmitting portions 38 in the lower source reflector 30 ; the light transmitting portions may be apertures , slots , transparent materials , translucent materials , or any other light transmitting element . the amount of light directed downward from the source 22 may be varied by changing the relative sizes of the upper and lower source reflectors 28 30 or by positioning an auxiliary downward reflector 42 in the light path . it is to be understood that some installations will benefit from the availability of light directed upward ( e . g . to illuminate gantries ), accordingly , the upper source reflector 28 may be fitted with light transmitting portions , the size of the upper source reflector 28 may be made smaller so as to permit light to reflect upward from the lower source reflector 30 , or auxiliary upward reflectors 44 may be positioned in the light path between the source 22 and the perimeter reflectors 34 . it is also possible to position auxiliary reflectors 42 44 to direct light to other selected locations . light from the source 22 striking the perimeter reflectors 34 is reflected to the activity area 24 . in many installations , the perimeter reflectors 34 will be formed and adjusted to aim the maximum light possible onto a work surface such as a tabletop 40 , storage shelves , or other objects to be illuminated within the activity area 24 . the perimeter reflectors 34 may be mounted in any manner desired to accommodate any room or module configuration ( e . g ., rectangular , oval , round , hexagonal , square , triangular , pentagonal , etc .). since most construction establishes square or rectangular activity areas 24 , those terms may be used for convenience here , but without limitation or exclusion of activity areas having any other plan or elevation configuration . an embodiment may be made with one or more concave perimeter reflectors 46 . convex or multiply curved perimeter reflectors 48 may also be used . planar reflectors 50 might be used to direct light as desired in some embodiments of this system . any combination of reflector shapes may be used in an installation to achieve optimum lighting performance . the perimeter reflectors 34 , in general will be elongated for being fitted at the upper and outer periphery of the activity area 24 to be illuminated . it will be possible to make the perimeter reflectors 34 from any reflective sheet , film , panel or other material . in a room 40 ft . square having a ceiling clearance of 16 feet , for example , aluminized mylar ® film 3 . 33 feet wide and 40 feet long could be installed by affixing the lower perimeter reflector edge 52 to the wall 14 . 27 feet above the floor and affixing the upper perimeter reflector edge to the ceiling 1 . 73 feet from the wall at the top of each wall or interior partition . light emanating from the source 22 would travel to the perimeter reflector 34 and be reflected downward and inward toward the activity area . it will be possible to hold a reflective sheet or film at various convex curves by appropriate selection of the points on the wall and ceiling to which the lower perimeter reflector edge 52 and upper perimeter reflector edge 54 are attached . if it is necessary to form a concave reflector section , reflective film may be attached to battens that can be flexed to the desired section curve and held with tension members such as wire , string , rope , banding , strips , webbing , rods , and other equivalent structures . battens may be omitted if the reflector is fitted to any resilient sheet material that can be deformed in the desired manner . for example , a reflective metal sheet could be formed to the desired curve and then installed at the appropriate location . it would also be possible to hold a resilient metal sheet at the appropriate cross - section curve with tension members . alternatively , rigid , flexible , resilient , or semi - rigid pre - formed , reflector panels could be fabricated from metals , polymer resins , composites , flexible sheets , or other materials and ready for installation at the desired height to route light from the source 22 toward the activity area 24 . lower perimeter reflector edges 52 may be attached to the wall directly by adhesives or fasteners 56 , or by fitting the edge into a channel 58 that may be attached to the wall . a wall attachment member 60 may be used to link the upper perimeter reflector edge 54 to the wall 36 or a ceiling attachment member 62 can be used to link the perimeter reflector 34 to the ceiling , roof trusses , or other structural element available for mounting . both the wall attachment member 60 and the ceiling attachment member 62 may be made adjustable to facilitate system layout , installation and setup . a channel 58 , tube , rod , reinforcement , or stiffener of any sort may be fitted to either edge of the perimeter reflector , if deemed beneficial . perimeter reflectors may be mounted between support columns or in other modular room subdivisions in order to evenly light a room using more than a single source 22 . a spreader 64 member may extend between the upper perimeter edge 54 and a riser 66 member which may be planar or be comprised of a multiplicity of discrete battens , shafts , rods , and their equivalents . the lower perimeter reflector edge 52 , and the lower end or edge of the riser 66 can be connected within or by a channel 58 , by fasteners , by adhesives , by sonic welding , heat sealing , or any other means . the spreader 64 and riser 66 may be connected by any convenient type of fastener , or may be formed integrally . it may be possible also to form the spreader 64 , riser 66 , and reflector 34 integrally or as an assembly ready for hanging . for example , coiled reflective stock could be formed into perimeter reflectors 34 of any desired length using a forming apparatus similar , or identical , to the machines used to form continuous steel siding . in the case of assembled or integrally formed back - to - back perimeter reflector 68 elements having sufficient stiffness , it may be possible to omit either the spreader 64 or the riser 66 or both . back - to - back perimeter reflectors 68 may be suspended from ceiling attachment members 62 that are affixed to preexisting components of the structure , such as roof trusses . if necessary , suitable struts , tubes , rods , pipes , beams , or other members may be added to the structure to enable the ceiling attachment members 62 to be attached so as to make it convenient to suspend the perimeter reflectors . perimeter reflectors may be made of materials light enough to be installed in a manner similar to that used to install suspended acoustical tile grid . it will be possible for skilled electrical contractors to properly install the light source 22 at the desired location and height without undue effort . the type and wattage of the lamp 26 may be determined based on the activities contemplated , the area to be illuminated , the room factor , and the ceiling height . it is to be understood that certain types of lamp 26 may yield different operating characteristics that others . for example , lamps may be equipped with internal or external reflectors to enhance the emission of light radially . other lamps 26 may be available only in shapes that are incompatible with embodiments according to this specification . it is believed , however that high efficiency metal halide , high pressure sodium and other lamps 26 are available in configurations suitable for practicing the invention . the width of the perimeter reflector 34 may be affected by several factors . if the light emanating from the source 22 is focused in a thin disk or layer having little divergence between the source 22 and the perimeter reflector 34 ( i . e ., radially collimated ), the perimeter reflector 34 can be narrow . if light from the source diverges substantially , the perimeter reflector 34 will be more effective if it is wide enough to redirect the largest practical portion of the source beam toward the activity area 24 . likewise , if light from the source is divergent , it might be preferred to install a concave perimeter reflector 46 to focus the light onto the activity area 24 at the height above the floor 32 where most of the activities to be illuminated occur . on the other hand , if the source 22 projects a narrow beam , it may be desirable to use a narrow , convex perimeter reflector 48 to disperse light more evenly into the activity area . it might also be practical to use highly reflective , non - imaging , ( e . g ., white ) planar or curved perimeter reflector panels 50 to direct light from the source 22 to the activity area 24 in some installations ( e . g ., where a substantial amount of upward light is desired ). it should be noted that various tints , colors , coverings , coatings , or materials for fabrication may be incorporated in the manufacture of perimeter reflectors to achieve desired lighting effects in applications where maximum lighting efficacy is not essential . it should also be noted that embodiments are particularly suited to improving illumination of large areas that have limited ceiling clearance by reducing shadows and by reducing variations in light intensity within an illuminated activity area 24 . embodiments may also be installed for illuminating only the specific vertical segment in which the activity area is present . it may be possible to direct much of the source 22 output to the surface of a work table 40 or to elevated work areas . [ 0048 ] fig2 is a reflected ceiling view of the lighting system of fig1 showing luminaires , or light sources 22 centered in modular grids of perimeter reflectors 34 . if the individual modules depicted were 40 ft .× 40 ft . the figure would show the lighting installation for a 120 ft .× 160 ft . space ( 19 , 200 ft 2 ). support columns 70 might be required at six locations within the structure to support the roof , ceiling , or other floors of a multi - story structure . [ 0049 ] fig3 depicts several types of light sources 22 , or luminaires that may comprise elements of embodiments according to this disclosure . embodiments may incorporate a luminaire adapted for elongated lamps 72 that emit most light radially . lenses or condensers may be included in a luminaire 74 to produce radially collimated light . a dual reflector luminaire 76 may accommodate an elongated , radially emitting lamp or other lamp types . also shown in fig3 is a lens 77 adapted for focusing or collimating the light emitted from the lamp 26 radially . although the lens 77 depicted is an annular lens with prism elements , it is to be understood that linear elements , fresnel lenses , or other lens types could perform similarly . it is to be understood also that more than one annular lens , or a single annular lens having multiple focusing elements , may be positioned to surround an elongated lamp 26 such as the one shown in the luminaire 76 in order to refract light emitted from the lamp 26 toward the perimeter reflectors 34 . [ 0051 ] fig4 is an alternative embodiment of the lighting system of fig1 wherein a narrow beam light source having a lamp 78 is situated below an elevated pyramidal or conical central dispersion reflector 80 . it is to be understood that such a narrow beam source 78 may equivalently be mounted above the pyramidal or conical central dispersion reflector 80 , and that in such a configuration , the central reflector 80 would be inverted from the depiction of fig4 . this embodiment may be preferred for temporary installations , when an existing narrow beam or cylindrically collimated light source is available at the site of system 20 installation , or when multiple lamps 26 are to be operated simultaneously to provide greater light intensity , to obtain desired color balance , or for any other purpose . in this manner , lighting efficacy could conveniently be increased by combining lamps of differing types . it would be possible , for example , to fit a light source 22 with a low pressure sodium lamp which , although very efficient , produces monochromatic light that many people find objectionable . a narrow beam source 78 of a different type , such as metal halide , could be distributed by a pyramidal or conical central dispersion reflector 80 to add light from other portions of the visible spectrum to improve color balance with superior performance in terms of lumens per watt . it may also be possible to provide multiple types of lamps 26 within a single source or luminaire 22 , from each of which light emanates radially toward the perimeter reflectors 34 . lamps 26 may be fitted with internal or external reflector elements , lenses , prisms , or other components that will enhance radially or conically directed light emission , and lead to further improvements to the utility of embodiments according to this specification . [ 0054 ] fig5 shows an optional mounting configuration for installation of the perimeter reflectors of the lighting system of fig1 . clips 82 or other linking components of any known structure affixed to the upper perimeter reflector edge 54 may engage a rope , bar , cable , wire , elongated member , or other support 84 . the support member 84 may be attached to trusses , joists , walls , ceilings , other building components , or structures by rollers , sheaves , eyes , or other suitable fasteners 86 installed near the ends of the perimeter reflector 34 . this configuration allows the perimeter reflector 34 , or sections of it , to be lowered and raised for cleaning , maintenance , and adjustment . although the perimeter reflector 34 is shown in a state ready for installation , the final location 88 of the installed perimeter reflector is shown by dashed lines . a central support 90 may engage the support member 84 to retain the perimeter reflector at the desired position . [ 0056 ] fig6 is an alternative embodiment of the lighting system of fig1 having an elevated central light source and a second light source situated below an elevated central reflector . this alternative embodiment is comprised of a luminaire 22 fitted with a lamp 26 , an upper source reflector 28 , a lower source reflector 30 that , in combination , direct light toward the perimeter reflectors 34 , and a reflective inverted dispersion pyramid or cone 80 positioned below the lower reflector 30 . the dispersion cone or pyramid 80 may be attached to , or formed integrally with , the upper luminaire 22 . in addition , a second narrow beam light source 78 such as a spotlight or axially collimating luminaire may be positioned below the upper luminaire . the second source may be mounted at a convenient location on the floor , atop installed shelving , or at any other desired location . the dispersion pyramid or cone 80 may be deformed somewhat to compensate for a non - vertical beam where the narrow beam light source 78 is not installed directly below the center of the upper luminaire 22 . it is to be understood that the dispersion cone 80 could also be positioned above the radial emitting luminaire 22 equivalently , or both above and below the radially emitting luminaire 22 . advantages available from this configuration may include the ability to control the light level supplied to an activity area 24 in two or three steps , ability to use lamps that are impractical or impossible to fit with dimmers , increased light output , ability to use more than one type of lamp at the same time ( e . g ., low pressure sodium and metal halide lamps could be used simultaneously to yield higher efficiency with acceptable color balance ), increased amount of light available at the desired places within the activity area 24 , redundancy to avoid blackout upon cessation of light output by a source , improved access for maintenance , and less heat buildup . [ 0058 ] fig6 discloses an alternative reduced shadow system 20 for illuminating an activity 24 area for being occupied by one or more persons , the activity area 24 being above a floor 32 and within a perimeter , comprising : a central light source 22 that emits light radially and generally parallel to the floor 32 , an upper reflective surface 28 positioned above a lamp 26 the upper reflective surface 28 being shaped to direct light emitted by the lamp radially , a lower reflective surface 30 positioned below the lamp 26 , the lower reflective surface 30 being shaped to direct light emitted by the lamp 26 radially toward a perimeter reflector 34 spaced apart from the light source 22 , the perimeter reflector 34 being affixed to a structure enclosing the activity area and being further comprised of a curved reflective surface having a curve to reflect light emitted from the light source 22 toward the activity area 24 , a narrow beam upward source 78 positioned below the central light source 22 , and a dispersion reflector positioned 80 below the central light source 22 . the lighting system may be configured so that the perimeter reflector 34 is further comprised of a generally horizontal elongated surface positioned above the floor 32 and extending substantially along the perimeter of the activity area 24 . it is also possible to make the lighting system 20 with flexible material so that the curvature of the elongated perimeter reflector 34 reflective surface may be varied to achieve desired distribution of light within the activity area 24 or with the lamps 26 of the central source 22 and the upward source 78 are separately controllable so that the color balance and illumination intensity may be set at desired levels . the foregoing embodiments have been proposed and described as examples only , and are not to be construed as limitations of the invention . changes and modifications in the specifically described embodiments may be carried out without departing from the scope of the invention which is intended to be limited only by the scope of the appended claims . it is further to be understood that elements recited in the following claims are intended and deemed to include their structural and functional equivalents . drawing reference numbers 20 reduced shadow system for illuminating an activity area 22 light source , or luminaire 24 activity area 26 electrically powered lamp 28 upper source reflector 30 lower source reflector 32 floor 34 perimeter reflectors , in general 36 wall 38 lower source reflector light transmitting portions 40 tabletop 42 auxiliary down reflector 44 auxiliary up reflector 46 concave perimeter reflector 48 convex perimeter reflector 50 planar perimeter reflector 52 lower perimeter reflector edge 54 upper perimeter reflector edge 56 fastener 58 channel 60 wall attachment member 62 ceiling attachment member 64 spreader 66 riser 68 back - to - back perimeter reflectors 70 roof truss support column location 72 luminaire adapted for elongated lamps 74 collimating luminaire with lens 76 dual reflector luminaire 77 lens , annular with prism elements 78 narrow beam upward source having a lamp 80 dispersion reflector pyramidal or conical 82 clip 84 elongated support member 86 eye , sheave , or roller 88 location of installed perimeter reflector 90 central support member