Controlled environment light fixture

Abstract

Controlled environment light fixture configurations include an LED light source. The light fixtures can be installed and removed from below the ceiling. The light fixture can be installed and removed without opening the lens frame of the light fixture. The light fixture includes a sealed housing and seals to the ceiling when installed. The light fixtures are provided in exterior dimension sizes that allow the fixtures to be installed in a variety of controlled environment ceilings in recessed configurations. The lower surface exposed to the controlled environment is free of welds and grinds in order to provide a corrosion resistant surface.

1 - 20 . (canceled) 
     
     
         21 . A light fixture for a controlled environment ceiling application, the light fixture comprising:
 an enclosure that includes an aluminum housing and a lens frame;   an LED light source carried by the enclosure;   the LED light source being mounted directly to the aluminum housing such that the housing functions as a conductive heat sink for the LED circuit board.   
     
     
         22 . The light fixture of  claim 21 , wherein the aluminum housing includes an integral aluminum LED mount that defines a substantially vertical surface when the light fixture is mounted in the ceiling; the LED light source being mounted to the substantially vertical surface of the integral aluminum LED mount. 
     
     
         23 . The light fixture of  claim 22 , wherein the aluminum housing defines a plurality of fins used to increase surface area of the housing to remove heat from the housing. 
     
     
         24 . The light fixture of  claim 23 , wherein the housing includes an extruded aluminum envelope disposed between first and second aluminum end caps; the extruded aluminum envelope defining the plurality of fins. 
     
     
         25 . The light fixture of  claim 24 , wherein the extruded aluminum envelope defines a plurality of channels; the end caps being secured to the envelope with threaded fasteners that engage the channels. 
     
     
         26 . The light fixture of  claim 25 , wherein each of the end caps defines a slot; the envelope having first and second ends disposed in the slots of the ends caps; and a sealing material disposed in the slots between the envelope ends and the end caps. 
     
     
         27 . A light fixture for a controlled environment ceiling; the light fixture comprising:
 an enclosure having a lens frame sealed to a housing;   the housing having a mounting surface adapted to engage the ceiling when the light fixture is installed;   the housing having a height above the mounting surface of no more than two inches; and   an LED light source disposed within the enclosure.   
     
     
         28 . The light fixture of  claim 27 , further comprising an LED power supply carried within the enclosure and a light guide plate having a plurality of edges; the light guide plate being disposed above the lens frame of the enclosure; the LED light source being arranged to direct light into an edge of the light guide plate. 
     
     
         29 . The light fixture of  claim 27 , wherein the lens frame includes a lens and wherein the LED light source is arranged to direct light in a direction substantially perpendicular to the lens of the lens frame. 
     
     
         30 . The light fixture of  claim 27 , wherein the lens frame includes a lens and wherein the LED light source is arranged to direct light in a direction substantially parallel to the lens of the lens frame. 
     
     
         31 . The light fixture of  claim 27 , wherein the mounting surface is an upwardly-facing mounting surface adapted to be disposed below the ceiling when the light fixture is installed; and further comprising a gasket carried by the housing; the gasket having a first portion for sealing the housing to the ceiling when the light fixture is installed in the ceiling; the first portion of the gasket being disposed on the upwardly-facing mounting surface. 
     
     
         32 . A light fixture for a controlled environment ceiling; the light fixture comprising:
 an enclosure having a lens frame and a housing; the housing adapted to fit into one of a 1×2, 2×2, and 2×4 light opening defined by a 2.0″ T-bar grid ceiling; and   an LED light source disposed within the enclosure.   
     
     
         33 . The light fixture of  claim 32 , wherein the enclosure can be mounted to ceilings formed from other systems including gypsum and panel systems. 
     
     
         34 . The light fixture of  claim 32 , further comprising an LED power supply carried within the enclosure and a light guide plate having a plurality of edges; the light guide plate being disposed above the lens frame of the enclosure; the LED light source being arranged to direct light into an edge of the light guide plate. 
     
     
         35 . The light fixture of  claim 32 , wherein the lens frame includes a lens and wherein the LED light source is arranged to direct light in a direction substantially perpendicular to the lens of the lens frame. 
     
     
         36 . The light fixture of  claim 32 , wherein the lens frame includes a lens and wherein the LED light source is arranged to direct light in a direction substantially parallel to the lens of the lens frame. 
     
     
         37 - 44 . (canceled) 
     
     
         45 . A light fixture for a controlled environment ceiling; the light fixture comprising:
 an enclosure having a lens frame and a housing;   an LED light source disposed within the enclosure; and   the lens frame having a lens carried by a stainless steel perimeter frame; the perimeter frame having a plurality of corners and an outwardly-facing surface exposed to the controlled environment when the light fixture is installed; the corners of the stainless steel perimeter frame being free of welds.   
     
     
         46 . The light fixture of  claim 45 , wherein the housing has an upwardly-facing mounting surface used to mount the light fixture to the ceiling;
 a gasket having a first portion disposed on the upwardly-facing mounting surface to seal the housing to the ceiling; and   the stainless steel perimeter frame engaging the gasket.   
     
     
         47 . The light fixture of  claim 45 , wherein the entire outwardly-facing surface is free of welds. 
     
     
         48 . A light fixture for a controlled environment ceiling; the light fixture comprising:
 an enclosure that includes a housing and a lens frame; the housing having an upwardly-facing mounting surface adapted to be disposed below the ceiling when the light fixture is installed;   an LED light source disposed within the enclosure;   an LED power supply disposed within the enclosure;   a gasket carried by the housing; the gasket having a first portion for sealing the housing to the ceiling when the light fixture is installed in the ceiling; the first portion of the gasket being disposed on the upwardly-facing mounting surface;   a light guide plate disposed within the enclosure; the light guide plate having a plurality of edges; and the LED light source arranged to direct light into an edge of the light guide plate; and   the light fixture having a symmetric/asymmetric light distribution pattern.   
     
     
         49 . The light fixture of  claim 48 , wherein the lens frame includes a lens; the lens having the symmetric/asymmetric light distribution pattern. 
     
     
         50 . The light fixture of  claim 48 , wherein the light guide plate has the symmetric/asymmetric light distribution pattern. 
     
     
         51 . The light fixture of  claim 48 , further comprising a diffuser disposed below the light guide plate; the diffuser having the symmetric/asymmetric light distribution pattern.