A pixel is located at the junction of each row and column control lines. Passive matrix displays use one transistor to address each row and one to address each column of pixels. Pixels are turned on when both row and column lines are energized and off when both control lines are de-energized. This addressing scheme is called multiplexing. The residual electrical current that travels down each control line can cause crosstalk at unselected pixels.
Crosstalk partially darkens pixels and lowers the display's overall contrast.
This usually appears on a passive matrix PowerBook display as two dark boxes, parallel to each other on the display. Because of the transistors, pixels can be turned on and off at a very fast rate. The transistor at each pixel eliminates the crosstalk phenomenon, which lowers contrast on an FSTN display. The TFT method eliminates the time dependency associated with multiplexed displays by directly addressing each pixel. In This Issue T he Different Flavors of SCSI Sometimes hooking up multiple SCSI devices was confusing.