Thermal imaging system with integrated thermal chopper

摘要

A thermal imaging system (10) contains a focal plane array (14) including a plurality of thermal sensors (50) mounted on a substrate (52). The focal plane array (14) generates both a reference signal which represents the temperature of the substrate (52) and a biased signal corresponding to the total radiance emitted by a scene (11). Electronics (16) process the reference signal and the biased signal to obtain an unbiased signal representing radiance differences emitted by objects in the scene (11). A thermoelectric cooler/heater (38) may be provided to optimally adjust the temperature of the substrate (52) to improve overall image quality. Each thermal sensor (50) contains an electrode (66 and 68) that electrically couples the thermal sensor (50) to the substrate (52) and also allows the thermal sensor (50) to deflect, contact, and thermally shunt with the substrate (52).