Reflectors optimized for led lighting fixture

Abstract

An LED apparatus and method of operating the apparatus is provided for illumination toward a preferential side in a downward and forward direction. The LED apparatus includes a printed circuit board; a plurality of LED devices arranged in one or more horizontal rows and mounted to the printed circuit board; a secondary lens associated with each of the LED devices and being disposed on the printed circuit board; and a diffuse horizontal reflector disposed between the printed circuit board and the secondary lenses. The horizontal reflector may be made a diffuse reflector by providing a roughened bottom surface of the secondary lenses including flanges, thereby enabling the use of a specularly reflective material on the printed circuit board surface while still obtaining diffuse reflection.

1 . An LED lighting apparatus for illumination toward a preferential side in a vertically downward and horizontally forward direction, comprising:
 a horizontal printed circuit board (PCB);   a plurality of LED devices each comprising an LED emitter covered by a primary lens, the plurality of LED devices being arranged in one or more horizontal rows and mounted to the printed circuit board;   a secondary lens associated with each one of the LED devices and being disposed on the printed circuit board;   a PCB reflector being a horizontal reflector disposed between the printed circuit board and the secondary lenses; and   a roughened bottom surface of the secondary lenses for diffusing LED light that passes therethrough, including light reflected by the PCB reflector.   
     
     
         2 . (canceled) 
     
     
         3 . The LED lighting apparatus of  claim 1  wherein the PCB reflector has a plurality of openings that fit closely around each of the plurality of LED devices, thereby allowing the LED devices to protrude through the PCB reflector. 
     
     
         4 - 6 . (canceled) 
     
     
         7 . The LED lighting apparatus of  claim 1  wherein:
 each of the secondary lenses has a plurality of leveling bosses extending below the bottom surface; and 
 the PCB reflector has corresponding through holes to allow direct contact of the leveling bosses with the printed circuit board. 
 
     
     
         8 . (canceled) 
     
     
         9 . The LED lighting apparatus of  claim 1 , wherein:
 the printed circuit board is disposed in a housing and a cover lens is mounted to the housing to cover the LED devices.   
     
     
         10 . The LED lighting apparatus of  claim 9  wherein:
 non-vertical surfaces that are exposed to an underside of the cover lens have a diffusely reflecting surface. 
 
     
     
         11 . The LED lighting apparatus of  claim 10  further comprising:
 a vertical specular reflector disposed parallel with the one or more horizontal rows of LED devices. 
 
     
     
         12 - 13 . (canceled) 
     
     
         14 . A method of directing illumination from an LED lighting apparatus toward a preferential side in a vertically downward and horizontally forward direction comprising the steps of:
 mounting one or more rows of LED devices on a horizontally oriented printed circuit board (PCB);   associating a secondary lens with each LED device;   disposing a horizontal PCB reflector around the LED devices, between the printed circuit board and a bottom surface of each of the secondary lenses; and   diffusing light that reflects off of the PCB reflector by making the bottom surfaces of the secondary lenses to be diffusely translucent.   
     
     
         15 - 17 . (canceled) 
     
     
         18 . The method of  claim 14  further comprising the steps of:
 aligning the one or more rows of LED devices in a horizontal direction that is orthogonal to the horizontally forward direction; and 
 disposing a vertical specular reflector parallel with the one or more rows of LED devices. 
 
     
     
         19 - 20 . (canceled) 
     
     
         21 . The method of  claim 14  further comprising the step of:
 providing a diffusely reflective surface on non-vertical surfaces that are exposed to light from the LED devices. 
 
     
     
         22 . The method of  claim 14  further comprising the step of:
 floating the PCB reflector by providing through holes in the PCB reflector and leveling bosses extending therethrough to establish direct contact between the secondary lenses and the printed circuit board. 
 
     
     
         23 . The method of  claim 14  further comprising the step of:
 selecting sheet material for the PCB reflector according to cost, without limiting its reflective surface to being a diffuse reflector. 
 
     
     
         24 . The method of  claim 14  further comprising holding the secondary lenses in place on the printed circuit board by the steps of:
 providing flanges that extend horizontally from the secondary lenses; and 
 securing a module cover over the printed circuit board and the flanges; while providing one or more openings that allow the secondary lenses to protrude therethrough. 
 
     
     
         25 . The method of  claim 24  further comprising the step of:
 attaching a diffusely reflecting horizontal module reflector over at least a portion of the module cover that is exposed to light from the LED devices. 
 
     
     
         26 . The method of  claim 25  wherein a plurality of differently shaped secondary lens types is used to manufacture a plurality of different LED lighting apparatus types, minimizing manufacturing parts inventory by further method steps of:
 using a single version of the module cover for holding any one of a set of the differently shaped secondary lens types; and 
 using a set of different module reflectors wherein each of the module reflectors has openings that are sized and positioned to closely fit around the secondary lenses of a corresponding secondary lens type. 
 
     
     
         27 . The LED lighting apparatus of  claim 10  wherein:
 a surface exposed to an underside of the cover lens has a coating of diffusely reflecting paint. 
 
     
     
         28 . The LED lighting apparatus of  claim 3  wherein the PCB reflector is constructed of a plastic sheet having a specular reflecting surface. 
     
     
         29 . The LED lighting apparatus of  claim 28  wherein the PCB reflector is constructed of a polyester sheet material. 
     
     
         30 . The LED lighting apparatus of  claim 1  further comprising:
 flanges that horizontally extend out from the secondary lenses; and 
 a module cover secured over the printed circuit board, and having one or more openings sized and positioned such that the secondary lenses protrude therethrough, while the lens flanges are at least partly covered by the module cover around the openings therein. 
 
     
     
         31 . The LED lighting apparatus of  claim 30  further comprising:
 a diffusely reflecting horizontal module reflector mounted over the module cover. 
 
     
     
         32 . The LED lighting apparatus of  claim 31  wherein:
 the module reflector covers a portion of the module cover that is exposed to light from the LED devices. 
 
     
     
         33 . The LED lighting apparatus of  claim 31  further comprising:
 a set of different module reflectors corresponding to a set of differently shaped secondary lens types, wherein each of the module reflectors has openings that are sized and positioned to closely fit around the secondary lenses of a corresponding secondary lens type. 
 
     
     
         34 . The LED lighting apparatus of  claim 31  wherein:
 the module reflector is constructed of a material selected from the group consisting of: reflective adhesive tape, textured foil, PET plastic having a micro cellular structure, and white plastic with a roughened surface.