<s>
Large-screen	B-General_Concept
television	I-General_Concept
technology	I-General_Concept
(	O
colloquially	O
big-screen	B-General_Concept
TV	I-General_Concept
)	O
developed	O
rapidly	O
in	O
the	O
late	O
1990s	O
and	O
2000s	O
.	O
</s>
<s>
Prior	O
to	O
the	O
development	O
of	O
thin-screen	O
technologies	O
,	O
rear-projection	O
television	O
was	O
standard	O
for	O
larger	O
displays	O
,	O
and	O
jumbotron	B-Application
,	O
a	O
non-projection	O
video	O
display	O
technology	O
,	O
was	O
used	O
at	O
stadiums	O
and	O
concerts	O
.	O
</s>
<s>
Various	O
thin-screen	O
technologies	O
are	O
being	O
developed	O
,	O
but	O
only	O
liquid	B-Device
crystal	I-Device
display	I-Device
(	O
LCD	B-Device
)	O
,	O
plasma	O
display	O
(	O
PDP	O
)	O
and	O
Digital	B-General_Concept
Light	I-General_Concept
Processing	I-General_Concept
(	O
DLP	B-General_Concept
)	O
have	O
been	O
publicly	O
released	O
.	O
</s>
<s>
Recent	O
technologies	O
like	O
organic	B-Device
light-emitting	I-Device
diode	I-Device
(	O
OLED	B-Device
)	O
as	O
well	O
as	O
not-yet-released	O
technologies	O
like	O
surface-conduction	B-General_Concept
electron-emitter	I-General_Concept
display	I-General_Concept
(	O
SED	O
)	O
or	O
field	B-General_Concept
emission	I-General_Concept
display	I-General_Concept
(	O
FED	O
)	O
are	O
in	O
development	O
to	O
replace	O
earlier	O
flat-screen	O
technologies	O
in	O
picture	B-Algorithm
quality	I-Algorithm
.	O
</s>
<s>
Large-screen	O
technologies	O
have	O
almost	O
completely	O
displaced	O
cathode-ray	B-Device
tubes	I-Device
(	O
CRT	B-Device
)	O
in	O
television	O
sales	O
due	O
to	O
the	O
necessary	O
bulkiness	O
of	O
cathode-ray	B-Device
tubes	I-Device
.	O
</s>
<s>
The	O
diagonal	O
screen	O
size	O
of	O
a	O
CRT	B-Device
television	O
is	O
limited	O
to	O
about	O
because	O
of	O
size	O
requirements	O
of	O
the	O
cathode-ray	B-Device
tube	I-Device
,	O
which	O
fires	O
three	O
beams	O
of	O
electrons	O
onto	O
the	O
screen	O
to	O
create	O
a	O
viewable	O
image	O
.	O
</s>
<s>
A	O
large-screen	B-General_Concept
TV	I-General_Concept
requires	O
a	O
longer	O
tube	O
,	O
making	O
a	O
large-screen	O
CRT	B-Device
TV	O
of	O
about	O
unrealistic	O
.	O
</s>
<s>
Newer	O
large-screen	B-General_Concept
televisions	I-General_Concept
are	O
comparably	O
thinner	O
.	O
</s>
<s>
Display	B-General_Concept
resolution	I-General_Concept
:	O
the	O
number	O
of	O
pixels	B-Algorithm
in	O
each	O
dimension	O
on	O
a	O
display	O
.	O
</s>
<s>
Dot	O
pitch	O
:	O
This	O
is	O
the	O
size	O
of	O
an	O
individual	O
pixel	B-Algorithm
,	O
which	O
includes	O
the	O
length	O
of	O
the	O
subpixels	O
and	O
distances	O
between	O
subpixels	O
.	O
</s>
<s>
It	O
can	O
be	O
measured	O
as	O
the	O
horizontal	O
or	O
diagonal	O
length	O
of	O
a	O
pixel	B-Algorithm
.	O
</s>
<s>
A	O
smaller	O
dot	O
pitch	O
generally	O
results	O
in	O
sharper	O
images	O
because	O
there	O
are	O
more	O
pixels	B-Algorithm
in	O
a	O
given	O
area	O
.	O
</s>
<s>
In	O
the	O
case	O
of	O
CRT	B-Device
based	O
displays	O
,	O
pixels	B-Algorithm
are	O
not	O
equivalent	O
to	O
the	O
phosphor	O
dots	O
,	O
as	O
they	O
are	O
to	O
the	O
pixel	B-Algorithm
triads	O
in	O
LC	B-Device
displays	I-Device
.	O
</s>
<s>
For	O
an	O
LC	B-Device
display	I-Device
it	O
is	O
defined	O
as	O
the	O
total	O
time	O
it	O
takes	O
for	O
a	O
pixel	B-Algorithm
to	O
transition	O
from	O
black	O
to	O
white	O
,	O
and	O
then	O
white	O
to	O
black	O
.	O
</s>
<s>
Aspect	B-General_Concept
ratio	I-General_Concept
:	O
The	O
ratio	O
of	O
the	O
display	O
width	O
to	O
the	O
display	O
height	O
.	O
</s>
<s>
The	O
aspect	B-General_Concept
ratio	I-General_Concept
of	O
a	O
traditional	O
television	O
is	O
4:3	O
,	O
which	O
is	O
being	O
discontinued	O
;	O
the	O
television	O
industry	O
is	O
currently	O
changing	O
to	O
the	O
16:9	O
ratio	O
typically	O
used	O
by	O
large-screen	O
,	O
high-definition	O
televisions	O
.	O
</s>
<s>
A	O
pixel	B-Algorithm
on	O
an	O
LCD	B-Device
consists	O
of	O
multiple	O
layers	O
of	O
components	O
:	O
two	O
polarizing	O
filters	O
,	O
two	O
glass	O
plates	O
with	O
electrodes	O
,	O
and	O
liquid	B-Device
crystal	I-Device
molecules	O
.	O
</s>
<s>
The	O
liquid	B-Device
crystals	I-Device
are	O
sandwiched	O
between	O
the	O
glass	O
plates	O
and	O
are	O
in	O
direct	O
contact	O
with	O
the	O
electrodes	O
.	O
</s>
<s>
The	O
electrodes	O
are	O
treated	O
with	O
a	O
layer	O
of	O
polymer	B-Language
to	O
control	O
the	O
alignment	O
of	O
liquid	B-Device
crystal	I-Device
molecules	O
in	O
a	O
particular	O
direction	O
.	O
</s>
<s>
Twisted	O
nematic	O
liquid	B-Device
crystals	I-Device
are	O
naturally	O
twisted	O
,	O
and	O
are	O
commonly	O
used	O
for	O
LCDs	B-Device
because	O
they	O
react	O
predictably	O
to	O
temperature	O
variation	O
and	O
electric	O
current	O
.	O
</s>
<s>
When	O
the	O
liquid	B-Device
crystal	I-Device
material	O
is	O
in	O
its	O
natural	O
state	O
,	O
light	O
passing	O
through	O
the	O
first	O
filter	O
will	O
be	O
rotated	O
(	O
in	O
terms	O
of	O
polarity	O
)	O
by	O
the	O
twisted	O
molecule	O
structure	O
,	O
which	O
allows	O
the	O
light	O
to	O
pass	O
through	O
the	O
second	O
filter	O
.	O
</s>
<s>
When	O
voltage	O
is	O
applied	O
across	O
the	O
electrodes	O
,	O
the	O
liquid	B-Device
crystal	I-Device
structure	O
is	O
untwisted	O
to	O
an	O
extent	O
determined	O
by	O
the	O
amount	O
of	O
voltage	O
.	O
</s>
<s>
This	O
filter	O
will	O
block	O
the	O
passage	O
of	O
light	O
because	O
of	O
the	O
difference	O
in	O
polarity	O
orientation	O
,	O
and	O
the	O
resulting	O
pixel	B-Algorithm
will	O
be	O
black	O
.	O
</s>
<s>
The	O
amount	O
of	O
light	O
allowed	O
to	O
pass	O
through	O
at	O
each	O
pixel	B-Algorithm
can	O
be	O
controlled	O
by	O
varying	O
the	O
corresponding	O
voltage	O
accordingly	O
.	O
</s>
<s>
In	O
a	O
color	B-Device
LCD	I-Device
each	O
pixel	B-Algorithm
consists	O
of	O
red	O
,	O
green	O
,	O
and	O
blue	O
subpixels	O
,	O
which	O
require	O
appropriate	O
color	O
filters	O
in	O
addition	O
to	O
the	O
components	O
mentioned	O
previously	O
.	O
</s>
<s>
Each	O
subpixel	O
can	O
be	O
controlled	O
individually	O
to	O
display	O
a	O
large	O
range	O
of	O
possible	O
colors	O
for	O
a	O
particular	O
pixel	B-Algorithm
.	O
</s>
<s>
The	O
electrodes	O
on	O
one	O
side	O
of	O
the	O
LCD	B-Device
are	O
arranged	O
in	O
columns	O
,	O
while	O
the	O
electrodes	O
on	O
the	O
other	O
side	O
are	O
arranged	O
in	O
rows	O
,	O
forming	O
a	O
large	O
matrix	O
that	O
controls	O
every	O
pixel	B-Algorithm
.	O
</s>
<s>
Each	O
pixel	B-Algorithm
is	O
designated	O
a	O
unique	O
row-column	O
combination	O
,	O
and	O
the	O
pixel	B-Algorithm
can	O
be	O
accessed	O
by	O
the	O
control	O
circuits	O
using	O
this	O
combination	O
.	O
</s>
<s>
These	O
circuits	O
send	O
charge	O
down	O
the	O
appropriate	O
row	O
and	O
column	O
,	O
effectively	O
applying	O
a	O
voltage	O
across	O
the	O
electrodes	O
at	O
a	O
given	O
pixel	B-Algorithm
.	O
</s>
<s>
Simple	O
LCDs	B-Device
such	O
as	O
those	O
on	O
digital	O
watches	O
can	O
operate	O
on	O
what	O
is	O
called	O
a	O
passive-matrix	O
structure	O
,	O
in	O
which	O
each	O
pixel	B-Algorithm
is	O
addressed	O
one	O
at	O
a	O
time	O
.	O
</s>
<s>
A	O
voltage	O
applied	O
to	O
one	O
pixel	B-Algorithm
can	O
cause	O
the	O
liquid	B-Device
crystals	I-Device
at	O
surrounding	O
pixels	B-Algorithm
to	O
untwist	O
undesirably	O
,	O
resulting	O
in	O
fuzziness	O
and	O
poor	O
contrast	O
in	O
this	O
area	O
of	O
the	O
image	O
.	O
</s>
<s>
LCDs	B-Device
with	O
high	O
resolutions	O
,	O
such	O
as	O
large-screen	O
LCD	B-Device
televisions	O
,	O
require	O
an	O
active-matrix	O
structure	O
.	O
</s>
<s>
This	O
structure	O
is	O
a	O
matrix	O
of	O
thin-film	O
transistors	O
,	O
each	O
corresponding	O
to	O
one	O
pixel	B-Algorithm
on	O
the	O
display	O
.	O
</s>
<s>
The	O
switching	O
ability	O
of	O
the	O
transistors	O
allows	O
each	O
pixel	B-Algorithm
to	O
be	O
accessed	O
individually	O
and	O
precisely	O
,	O
without	O
affecting	O
nearby	O
pixels	B-Algorithm
.	O
</s>
<s>
The	O
following	O
are	O
types	O
of	O
LC	B-Device
display	I-Device
technologies	O
:	O
</s>
<s>
These	O
limitations	O
are	O
due	O
to	O
variation	O
in	O
the	O
angles	O
of	O
the	O
liquid	B-Device
crystal	I-Device
molecules	O
at	O
different	O
depths	O
,	O
restricting	O
the	O
angles	O
at	O
which	O
light	O
can	O
leave	O
the	O
pixel	B-Algorithm
.	O
</s>
<s>
In-Plane	O
Switching	O
(	O
IPS	O
)	O
:	O
Unlike	O
the	O
electrode	O
arrangement	O
in	O
traditional	O
TN	O
displays	O
,	O
the	O
two	O
electrodes	O
corresponding	O
to	O
a	O
pixel	B-Algorithm
are	O
both	O
on	O
the	O
same	O
glass	O
plate	O
and	O
are	O
parallel	O
to	O
each	O
other	O
.	O
</s>
<s>
The	O
liquid	B-Device
crystal	I-Device
molecules	O
do	O
not	O
form	O
a	O
helical	O
structure	O
and	O
instead	O
are	O
also	O
parallel	O
to	O
each	O
other	O
.	O
</s>
<s>
Because	O
the	O
twisted	O
molecule	O
structure	O
is	O
not	O
used	O
in	O
an	O
IPS	O
display	O
,	O
the	O
angle	O
at	O
which	O
light	O
leaves	O
a	O
pixel	B-Algorithm
is	O
not	O
as	O
restricted	O
,	O
and	O
therefore	O
viewing	O
angles	O
and	O
color	O
reproduction	O
are	O
much	O
improved	O
compared	O
to	O
those	O
of	O
TN	O
displays	O
.	O
</s>
<s>
Multi-Domain	O
Vertical	O
Alignment	O
(	O
MVA	O
)	O
:	O
In	O
this	O
type	O
of	O
display	O
the	O
liquid	B-Device
crystals	I-Device
are	O
naturally	O
arranged	O
perpendicular	O
to	O
the	O
glass	O
plates	O
but	O
can	O
be	O
rotated	O
to	O
control	O
light	O
passing	O
through	O
.	O
</s>
<s>
There	O
are	O
also	O
pyramid-like	O
protrusions	O
in	O
the	O
glass	O
substrates	O
to	O
control	O
the	O
rotation	O
of	O
the	O
liquid	B-Device
crystals	I-Device
such	O
that	O
the	O
light	O
is	O
channeled	O
at	O
an	O
angle	O
with	O
the	O
glass	O
plate	O
.	O
</s>
<s>
To	O
illuminate	O
a	O
particular	O
cell	O
,	O
the	O
electrodes	O
that	O
intersect	O
at	O
the	O
cell	O
are	O
charged	O
by	O
control	O
circuitry	O
and	O
electric	O
current	O
flows	O
through	O
the	O
cell	O
,	O
stimulating	O
the	O
gas	O
(	O
typically	O
xenon	B-Protocol
and	O
neon	B-Application
)	O
atoms	O
inside	O
the	O
cell	O
.	O
</s>
<s>
These	O
ionized	O
gas	O
atoms	O
,	O
or	O
plasmas	O
,	O
then	O
release	O
ultraviolet	B-Application
photons	O
that	O
interact	O
with	O
a	O
phosphor	O
material	O
on	O
the	O
inside	O
wall	O
of	O
the	O
cell	O
.	O
</s>
<s>
Every	O
pixel	B-Algorithm
on	O
the	O
display	O
is	O
made	O
up	O
of	O
three	O
subpixel	O
cells	O
.	O
</s>
<s>
Light	O
emitted	O
from	O
the	O
subpixel	O
cells	O
is	O
blended	O
together	O
to	O
create	O
an	O
overall	O
color	O
for	O
the	O
pixel	B-Algorithm
.	O
</s>
<s>
A	O
front-projection	B-Device
television	I-Device
uses	O
a	O
projector	O
that	O
is	O
separate	O
from	O
the	O
screen	O
which	O
could	O
be	O
a	O
suitably	O
prepared	O
wall	O
,	O
and	O
the	O
projector	O
is	O
placed	O
in	O
front	O
of	O
the	O
screen	O
.	O
</s>
<s>
CRT	B-General_Concept
rear-projection	I-General_Concept
television	I-General_Concept
:	O
Small	O
cathode-ray	B-Device
tubes	I-Device
create	O
the	O
image	O
in	O
the	O
same	O
manner	O
that	O
a	O
traditional	O
CRT	B-Device
television	O
does	O
,	O
which	O
is	O
by	O
firing	O
a	O
beam	O
of	O
electrons	O
onto	O
a	O
phosphor-coated	O
screen	O
;	O
the	O
image	O
is	O
projected	O
onto	O
a	O
large	O
screen	O
.	O
</s>
<s>
This	O
is	O
done	O
to	O
overcome	O
the	O
cathode-ray	B-Device
tube	I-Device
size	O
limit	O
which	O
is	O
about	O
,	O
the	O
maximum	O
size	O
for	O
a	O
normal	O
direct-view-CRT	O
television	O
set	O
(	O
see	O
image	O
)	O
.	O
</s>
<s>
The	O
projection	O
cathode-ray	B-Device
tubes	I-Device
can	O
be	O
arranged	O
in	O
various	O
ways	O
.	O
</s>
<s>
LCD	B-Device
rear-projection	I-Device
television	I-Device
:	O
A	O
lamp	O
transmits	O
light	O
through	O
a	O
small	O
LCD	B-Device
chip	O
made	O
up	O
of	O
individual	O
pixels	B-Algorithm
to	O
create	O
an	O
image	O
.	O
</s>
<s>
The	O
LCD	B-Device
projector	I-Device
uses	O
dichroic	O
mirrors	O
to	O
take	O
the	O
light	O
and	O
create	O
three	O
separate	O
red	O
,	O
green	O
,	O
and	O
blue	O
beams	O
,	O
which	O
are	O
then	O
passed	O
through	O
three	O
separate	O
LCD	B-Device
panels	I-Device
.	O
</s>
<s>
The	O
liquid	B-Device
crystals	I-Device
are	O
manipulated	O
using	O
electric	O
current	O
to	O
control	O
the	O
amount	O
of	O
light	O
passing	O
through	O
.	O
</s>
<s>
DLP	B-General_Concept
rear-projection	I-General_Concept
television	I-General_Concept
:	O
A	O
DLP	B-General_Concept
projector	I-General_Concept
creates	O
an	O
image	O
using	O
a	O
digital	O
micromirror	O
device	O
(	O
DMD	O
chip	O
)	O
,	O
which	O
on	O
its	O
surface	O
contains	O
a	O
large	O
matrix	O
of	O
microscopic	O
mirrors	O
,	O
each	O
corresponding	O
to	O
one	O
pixel	B-Algorithm
(	O
or	O
sub-pixel	O
)	O
in	O
an	O
image	O
.	O
</s>
<s>
Each	O
mirror	O
can	O
be	O
tilted	O
to	O
reflect	O
light	O
such	O
that	O
the	O
pixel	B-Algorithm
appears	O
bright	O
,	O
or	O
the	O
mirror	O
can	O
be	O
tilted	O
to	O
direct	O
light	O
elsewhere	O
(	O
where	O
it	O
is	O
absorbed	O
)	O
to	O
make	O
the	O
pixel	B-Algorithm
appear	O
dark	O
.	O
</s>
<s>
The	O
electrodes	O
are	O
connected	O
to	O
an	O
SRAM	B-Architecture
cell	O
located	O
under	O
each	O
pixel	B-Algorithm
,	O
and	O
charges	O
from	O
the	O
SRAM	B-Architecture
cell	O
move	O
the	O
mirrors	O
.	O
</s>
<s>
In	O
Laser	O
Phosphor	O
Display	O
technology	O
,	O
first	O
demonstrated	O
in	O
June	O
2010	O
at	O
InfoComm	B-General_Concept
,	O
the	O
image	O
is	O
provided	O
by	O
the	O
use	O
of	O
lasers	O
,	O
which	O
are	O
located	O
on	O
the	O
back	O
of	O
the	O
television	O
,	O
reflected	O
off	O
a	O
rapidly	O
moving	O
bank	O
of	O
mirrors	O
to	O
excite	O
pixels	B-Algorithm
on	O
the	O
television	O
screen	O
in	O
a	O
similar	O
way	O
to	O
cathode-ray	B-Device
tubes	I-Device
.	O
</s>
<s>
Though	O
large-screen	O
CRT	B-Device
TVs/monitors	O
exist	O
,	O
the	O
screen	O
size	O
is	O
limited	O
by	O
their	O
impracticality	O
.	O
</s>
<s>
The	O
bigger	O
the	O
screen	O
,	O
the	O
greater	O
the	O
weight	O
,	O
and	O
the	O
deeper	O
the	O
CRT	B-Device
.	O
</s>
<s>
The	O
Sony	O
PVM-4300	O
monitor	O
weighed	O
200	O
kg	O
(	O
440	O
⁠lb	O
)	O
and	O
had	O
the	O
largest	O
ever	O
CRT	B-Device
with	O
a	O
diagonal	O
display	O
.	O
</s>
<s>
LCDs	B-Device
reflect	O
very	O
little	O
light	O
,	O
allowing	O
them	O
to	O
maintain	O
contrast	O
levels	O
in	O
well-lit	O
rooms	O
and	O
not	O
be	O
affected	O
by	O
glare	O
.	O
</s>
<s>
Poor	O
black	O
level	O
:	O
Some	O
light	O
passes	O
through	O
even	O
when	O
liquid	B-Device
crystals	I-Device
completely	O
untwist	O
,	O
so	O
the	O
best	O
black	O
color	O
that	O
can	O
be	O
achieved	O
is	O
varying	O
shades	O
of	O
dark	O
gray	O
,	O
resulting	O
in	O
worse	O
contrast	O
ratios	O
and	O
detail	O
in	O
the	O
image	O
.	O
</s>
<s>
It	O
is	O
nearly	O
impossible	O
to	O
use	O
an	O
LCD	B-Device
without	O
some	O
image	O
warping	O
occurring	O
.	O
</s>
<s>
LCDs	B-Device
rely	O
heavily	O
on	O
thin-film	O
transistors	O
,	O
which	O
can	O
be	O
damaged	O
,	O
resulting	O
in	O
a	O
defective	B-General_Concept
pixel	I-General_Concept
.	O
</s>
<s>
This	O
is	O
also	O
improving	O
by	O
increasing	O
the	O
refresh	O
rate	O
of	O
LCDs	B-Device
.	O
</s>
<s>
The	O
Screen-door	B-General_Concept
effect	I-General_Concept
:	O
Individual	O
pixels	B-Algorithm
may	O
be	O
visible	O
on	O
the	O
large	O
screen	O
,	O
giving	O
the	O
appearance	O
that	O
the	O
viewer	O
is	O
looking	O
through	O
a	O
screen	O
door	O
.	O
</s>
<s>
Poor	O
black	O
level	O
:	O
Some	O
light	O
passes	O
through	O
even	O
when	O
liquid	B-Device
crystals	I-Device
completely	O
untwist	O
,	O
so	O
the	O
best	O
black	O
color	O
that	O
can	O
be	O
achieved	O
is	O
a	O
very	O
dark	O
gray	O
,	O
resulting	O
in	O
worse	O
contrast	O
ratios	O
and	O
detail	O
in	O
the	O
image	O
.	O
</s>
<s>
Some	O
newer	O
models	O
use	O
an	O
adjustable	B-General_Concept
iris	I-General_Concept
to	O
help	O
offset	O
this	O
.	O
</s>
<s>
Fixed	O
number	O
of	O
pixels	B-Algorithm
,	O
other	O
resolutions	O
need	O
to	O
be	O
scaled	O
to	O
fit	O
this	O
.	O
</s>
<s>
This	O
is	O
a	O
limitation	O
only	O
when	O
compared	O
with	O
CRT	B-Device
displays	I-Device
.	O
</s>
<s>
This	O
artifact	O
is	O
unique	O
to	O
single-chip	O
DLP	B-General_Concept
projectors	I-General_Concept
.	O
</s>
<s>
The	O
Rainbow	O
Effect	O
is	O
significant	O
only	O
in	O
DLP	B-General_Concept
displays	O
that	O
use	O
a	O
single	O
white	O
lamp	O
with	O
a	O
"	O
color	O
wheel	O
"	O
that	O
is	O
synchronized	O
with	O
the	O
display	O
of	O
red	O
,	O
green	O
and	O
blue	O
components	O
.	O
</s>
