| abstract |
A PNP bipolar transistor or an enhancement mode P-channel FET is used as a buffer to drive a video signal from an imager to video processing circuits. An endoscope with a solid state imager having a negative-going video pulse is used, with a video buffer located at or near the distal end to buffer the CCD video signal. The buffer employs a PNP bipolar transistor that is biased by a bias circuit for the base and a power supply for the collector, both located near the transistor, and a load for the emitter located at some distance from the transistor. |