摘要 |
An occupancy sensing electronic thermostat is described that includes a thermostat body having a curved exterior front surface, a dot matrix display mounted within the body viewable by a user in front of the front surface, a passive infrared sensor for measuring infrared energy and a shaped Fresnel lens having a smooth outer surface that extends across only a portion of the exterior front surface of the thermostat body. The Fresnel lens is shaped and curved so as to conform to and form a part of the curved exterior front surface of the thermostat body. A second, downwardly directed passive infrared sensor can also be provided to aid in the detection of an approaching user who intends to interact with the thermostat. |