Low power and low cost are primary requirements for an imaging
infrared camera serving law enforcement applications. These
include handheld, vehicle and helmet mounted systems for
search and surveillance applications. In this paper, a 120x160
amorphous silicon (a-Si) microbolometer-based uncooled
infrared camera technology offering a low cost, low power
solution to infrared surveillance for UGS applications is
presented.
A 120x160 micro infrared camera (MIRC) has been demonstrated
which exhibits a noise equivalent temperature difference
(NETD) sensitivity ~50 mK using f/1 optics and ~80 mK using
f/1.2 optics. This sensitivity has been achieved without the
use of a thermoelectric cooler for array temperature
stabilization thereby significantly reducing the power
requirements. Operation over the 0-60C ambient temperature
range has been demonstrated. Chopperless camera operation at a
20 Hz frame rate with power consumption of 380 mW without
display and 800 mW with display has also been demonstrated.
The 120x160 MIRC operates under digital signal processor (DSP)
control. This DSP-controlled architecture employs commercial
off-the-shelf DSP, A/D, memory and voltage regulator chips.
The camera also employs low cost optics, as well as low cost
wafer-level vacuum packaging. Wafer level vacuum packaging
offers a low cost, high volume approach for uncooled FPA
applications. In this paper, a-Si microbolometer technology
for the MIRC will be presented. Also, the key features and
performance parameters of the MIRC are presented.
