Patent attributes
Lighting device embodiments having a housing enclosing one or more interior volumes, along with a serviceable port in the housing to allow venting of one or more of the interior volumes, are disclosed. The lighting devices may further include internal venting paths to allow transfer of contaminating gases to the serviceable port, and a gas permeable pressure valve to allow transfer of contaminants from the interior of the lighting device. The pressure valve may be selectively permeable as a function of applied exterior pressure. The lighting device may also include one or more electronic circuit elements disposed in the one or more interior volumes, and a selectively permeable barrier element disposed in the housing having a first area exposed to one of the interior volumes and a second area exposed to a gas or liquid volume exterior to the housing to allow diffusion of browning contaminants from the one of the interior volumes to the gas or liquid volume exterior to the housing.
