US Patent 9587848 Building automation controller with rear projecting light

An HVAC controller may include a housing that is mountable on a vertical surface and a printed circuit board that is disposed within the housing. The printed circuit board may include a light source operably secured to the printed circuit board. A light guide may be secured relative to the printed circuit board such that light from the light source enters the light guide and propagates along the light guide. The light guide includes a light input pocket configured to receive light from the light source, a bifurcated inlet section optically coupled to the light input pocket, a light guide body extending from the bifurcated inlet section, and an output surface extending along a rear facing surface of the light guide body such that light exiting the output surface is projected onto the vertical surface to which the housing is mountable.