Table of Contents
Advertisement
User Manual 190S6FGT
LCD Panel Technology
Q: What is a Liquid Crystal Display?
A: A Liquid Crystal Display (LCD) is an optical device that is
commonly used to display ASCII characters and images on digital
items such as watches, calculators, portable game consoles, etc. LCD
is the technology used for displays in notebooks and other small
computers. Like light-emitting diode and gas-plasma technologies,
LCD allows displays to be much thinner than cathode ray tube
(CRT) technology.
LCD consumes much less power than LED and gas-displays because
it works on the principle of blocking light rather than emitting it.
Q: How are LCDs made?
A: LCDs are created from two glass plates separated from each
other at a distance of a few microns. The plates are filled with liquid
crystal and then sealed together. The top plate is colored with an
RGB pattern to make the color filter. Polarizers are then glued to
both plates. This combination is sometimes called 'glass' or 'cell.' The
LCD cell is assembled into a 'module' by adding the backlight, driver
electronics and frame.
Q: What is polarization ?
A: Polarization is basically directing light to shine in one direction.
Light is electromagnetic waves. Electric and magnetic fields oscillate
in a direction perpendicular to the propagation of the light beam.
The direction of these fields is called the 'polarization direction'.
Normal or non-polarized light has fields in several directions;
polarized light has a field in only one direction.
Q: What differentiates passive matrix LCDs from active matrix LCDs?
A: An LCD is made with either a passive matrix or an active matrix
display grid. An active matrix has a transistor located at each pixel
intersection, requiring less current to control the luminance of a
pixel. For this reason, the current in an active matrix display can be
switched on and off more frequently, improving the screen refresh
time (your mouse pointer will appear to move more smoothly
across the screen, for example). The passive matrix LCD has a grid
of conductors with pixels located at each intersection in the grid.
Q: How does a TFT LCD Panel work?
A: On each column and row of the TFT LCD panel, a data source
drive and a gate drive are attached, respectively. The TFT drain of
each cell is connected to the electrode. The molecular arrangement
of liquid crystal elements differ according to whether it is impressed
with voltage or not. It varies the direction of polarized light and the
amount of light by letting it through different arrays of liquid crystal
elements. When two polarized filters are arranged vertically on a
polarized light pole, the light that passes through the upper polarized
panel is turned 90 degrees along with the spiral structure of the
liquid crystal molecules and goes through the polarized filter at the
52
Advertisement
Table of Contents
