When a large number of pixels
is required in a display, it is not feasible to drive each
directly since then each pixel would require independent electrodes.
Instead, the display is multiplexed. In a multiplexed display,
electrodes on one side of the display are grouped and wired
together, and each group gets its own voltage source. On the
other side, the electrodes are also grouped, with each group
getting a voltage sink. The groups are designed so each pixel
has a unique, unshared combination of source and sink. The
electronics, or the software driving the electronics then
turns on sinks in sequence, and drives sources for the pixels
of each sink.
Important factors to consider when evaluating an LCD monitor
include resolution, viewable size, response time, matrix type
(passive or active), viewing angle, color support, brightness
and contrast ratio, aspect ratio, and input ports (e.g. DVI
or VGA). |
In-plane switching is an
LCD technology which aligns the liquid crystal cells in a
horizontal direction. In this method, the electrical field
is applied through each end of the crystal, but this requires
two transistors for each pixel instead of the one needed for
a standard thin-film transistor (TFT) display. This results
in blocking more transmission area requiring brighter backlights,
which consume more power making this type of display undesirable
for notebook computers. |