CHEMISTRY OF LCD
41491961-Lcd-Term-Paper.doc (Size: 1.35 MB / Downloads: 57)
In this term paper I will tell about what is a lcd, different types of lcd`s.how the lcd`s
wor k.Uses of lcd`s how lcd`s work,their general properties,structures,quality,brief history and
much more about lcd`s.
WHAT IS A LCD ?
liquid crystal display is a thin, flat electronic visual display that uses the light modulating properties of LIQUID CRYSTALS (LCs). LCs do not emit light directly.
WHAT ARE L Q RYSTALS ?
We learned t at t ere are t ree common states of matter: solid, li id or gaseous.
t e way t ey do because t eir molecules always maintain t eir orientation and stay in t e
same position wit respect to one anot er. The molecules in
are just the opposite:
They can change their orientation and move anywhere in the li uid. But there are some
substances that can exist in an odd state that is sort of li e a li uid and sort of li e a solid.
When they ar e in this state, their molecules tend to maintain their or ientation, li e the
molecules in a solid, but also move around to different positions, li e the molecules in a
li uid. This means that li uid crystals are neither a solid nor a li uid. That's how they ended
up with their seemingly contradictory name.
USES & PROPERT ES :
They are used in a wide range of applications including: computer monitors,televisions,
instrument panels, aircraft cockpit displays, signage, etc. They are common in consumer
devices such as video players, gaming devices, clocks, watches, calculators, and telephones.
LC s have displaced cathode ray tube(CRT) displays in most applications. They are usually
more compact, lightweight, portable, less expensive, more reliable, and easier on the eyes.
They are available in a wider range of screen sizes than CRT and plasma displays, and since
they do not use phosphors, they cannot suffer image bur n-in.
QUALITY CONTROL :
Some LCD panels have defective transistors, causing permanently lit or unlit pixels which are
always on or off. Unlike integrated circuits, LCD panels with a few defective pixels are
usually still usable. It is also economically prohibitive to discard a panel with just a few bad
pixels because LCD panels are much larger than ICs. Manufacturers have different standards
for determining a maximum acceptable number of defective pixels.