A bipolar image detector with smart functions

A new type of bipolar image detector has been developed which consists of bipolar sensor cells, bipolar frame memory cells, and signal transfer circuits. The imager with 100 H/spl times/70 V pixels was designed to detect near-infrared LED rays exactly and rapidly, and was fabricated using 2-/spl mu/m Bi-CMOS process. The device, utilizing operations specific to bipolar cells, amplifies signal charges and cancels noises to have a high signal-to-noise ratio (S/N) immune to a long time hold. It also offers several novel functions such as cancellation of external light signal, preliminary fast readout, and main readout of a selected part. Equipped with peripheral circuits, the chip is 3.66/spl times/3.7 mm in size and is very suitable for image processing use.