Appeal No. 2006-1049
Application No. 09/667,826
and structurally integrated therewith, said readout circuit comprising:
a sample and hold capacitor;
means for biasing the detector elements so as to provide an analog detection
signal from each detector element corresponding to the infrared radiation incident
thereon, wherein the analog detection signal is a voltage signal provided at a
sample node coupled to the sample and hold capacitor; and
means for correcting the analog detection signal from each detector element
by a discrete offset correction and providing a corrected analog detection signal,
wherein the discrete offset correction varies from detector element to detector
element and comprises an offset correction voltage added to, or subtracted from,
the analog detection signal, wherein said means for correcting subtracts or adds a
variable amount of charge from said sample and hold capacitor to provide a
corrected voltage signal at said sample node, and wherein said means for
correcting comprises a plurality of capacitors connected between said sample node
and a reference voltage and a corresponding plurality of switches coupled in series
with each respective capacitor and said reference voltage, wherein said plurality of
switches are selectively turned on or off to provide a desired amount of discrete
offset correction for each detector element.
28. An infrared focal plane array as set out in claim 27, wherein said readout
circuit further comprises means for controlling said means for correcting so as to
selectively open and close said plurality of switches in a time multiplexed manner
during readout of a plurality of separate detector elements.
29. An infrared focal plane array as set out in claim 27, wherein said
detector elements comprise microbolometer detector elements.
30. An infrared focal plane array as set out in claim 29, wherein said means
for said biasing comprises a constant current source coupled to said
microbolometer detector elements and said sample and hold capacitor.
31. An infrared focal plane array as set out in claim 27, wherein said readout
circuit further comprises a differential amplifier having first and second inputs, the
first input thereof coupled to said sample node and said second input thereof
coupled to a adjustable voltage source.
32. An infrared focal plane array as set out in claim 31, wherein said readout
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Last modified: November 3, 2007