<s>
A	O
surface-conduction	B-General_Concept
electron-emitter	I-General_Concept
display	I-General_Concept
(	O
SED	O
)	O
is	O
a	O
display	B-Device
technology	I-Device
for	O
flat	B-General_Concept
panel	I-General_Concept
displays	I-General_Concept
developed	O
by	O
a	O
number	O
of	O
companies	O
.	O
</s>
<s>
In	O
a	O
general	O
sense	O
,	O
a	O
SED	O
consists	O
of	O
a	O
matrix	O
of	O
tiny	O
cathode-ray	B-Device
tubes	I-Device
,	O
each	O
"	O
tube	O
"	O
forming	O
a	O
single	O
sub-pixel	O
on	O
the	O
screen	O
,	O
grouped	O
in	O
threes	O
to	O
form	O
red-green-blue	O
(	O
RGB	O
)	O
pixels	B-Algorithm
.	O
</s>
<s>
SEDs	O
combine	O
the	O
advantages	O
of	O
CRTs	O
,	O
namely	O
their	O
high	O
contrast	O
ratios	O
,	O
wide	O
viewing	B-General_Concept
angles	I-General_Concept
,	O
and	O
very	O
fast	O
response	O
times	O
,	O
with	O
the	O
packaging	O
advantages	O
of	O
LCD	O
and	O
other	O
flat	B-General_Concept
panel	I-General_Concept
displays	I-General_Concept
.	O
</s>
<s>
SEDs	O
are	O
closely	O
related	O
to	O
another	O
developing	O
display	B-Device
technology	I-Device
,	O
the	O
field	B-General_Concept
emission	I-General_Concept
display	I-General_Concept
,	O
or	O
FED	O
,	O
differing	O
primarily	O
in	O
the	O
details	O
of	O
the	O
electron	O
emitters	O
.	O
</s>
<s>
A	O
conventional	O
cathode	B-Device
ray	I-Device
tube	I-Device
(	O
CRT	O
)	O
is	O
powered	O
by	O
an	O
electron	O
gun	O
,	O
essentially	O
an	O
open-ended	O
vacuum	O
tube	O
.	O
</s>
<s>
When	O
viewed	O
from	O
a	O
distance	O
,	O
the	O
spots	O
,	O
known	O
as	O
"	O
sub-pixels	O
,	O
"	O
blend	O
together	O
in	O
the	O
eye	O
to	O
produce	O
a	O
single	O
picture	B-Algorithm
element	I-Algorithm
known	O
as	O
a	O
pixel	B-Algorithm
.	O
</s>
<s>
The	O
SED	O
replaces	O
the	O
single	O
gun	O
of	O
a	O
conventional	O
CRT	O
with	O
a	O
grid	O
of	O
nanoscopic	O
emitters	O
,	O
one	O
for	O
each	O
sub-pixel	O
of	O
the	O
display	O
.	O
</s>
<s>
This	O
allows	O
SED	B-General_Concept
displays	I-General_Concept
to	O
work	O
without	O
an	O
active	B-General_Concept
matrix	I-General_Concept
of	O
thin-film	O
transistors	O
that	O
LCDs	O
and	O
similar	O
displays	O
require	O
to	O
precisely	O
select	O
every	O
sub-pixel	O
,	O
and	O
further	O
reduces	O
the	O
complexity	O
of	O
the	O
emitter	O
array	O
.	O
</s>
<s>
However	O
,	O
this	O
also	O
means	O
that	O
changes	O
in	O
voltage	O
cannot	O
be	O
used	O
to	O
control	O
the	O
brightness	O
of	O
the	O
resulting	O
pixels	B-Algorithm
.	O
</s>
<s>
Instead	O
,	O
the	O
emitters	O
are	O
rapidly	O
turned	O
on	O
and	O
off	O
using	O
pulse-width	B-Algorithm
modulation	I-Algorithm
,	O
so	O
that	O
the	O
total	O
brightness	O
of	O
a	O
spot	O
at	O
any	O
given	O
time	O
can	O
be	O
controlled	O
.	O
</s>
<s>
SED	B-General_Concept
screens	I-General_Concept
consist	O
of	O
two	O
glass	O
sheets	O
separated	O
by	O
a	O
few	O
millimeters	O
,	O
the	O
rear	O
layer	O
supporting	O
the	O
emitters	O
and	O
the	O
front	O
the	O
phosphors	O
.	O
</s>
<s>
Electrodes	O
are	O
added	O
into	O
this	O
array	O
,	O
typically	O
using	O
platinum	B-Operating_System
,	O
leaving	O
a	O
gap	O
of	O
about	O
60	O
micrometers	O
between	O
the	O
columns	O
.	O
</s>
<s>
It	O
then	O
passes	O
through	O
the	O
LCD	O
layer	O
,	O
which	O
selectively	O
reduces	O
the	O
output	O
for	O
each	O
sub-pixel	O
.	O
</s>
<s>
In	O
front	O
of	O
the	O
LCD	O
,	O
shutters	O
are	O
small	O
colored	O
filters	O
,	O
one	O
for	O
each	O
RGB	O
sub-pixel	O
.	O
</s>
<s>
To	O
counteract	O
this	O
effect	O
and	O
improve	O
switching	O
speed	O
,	O
LCDs	O
use	O
an	O
Active	B-General_Concept
matrix	I-General_Concept
addressing	I-General_Concept
of	O
transparent	O
thin-film	O
transistors	O
to	O
switch	O
each	O
shutter	O
directly	O
.	O
</s>
<s>
Additionally	O
,	O
the	O
use	O
of	O
a	O
polarizer	O
to	O
create	O
the	O
shutter	O
limits	O
the	O
viewing	B-General_Concept
angles	I-General_Concept
where	O
a	O
visually	O
indistinguishable	O
contrast-ratio	O
experience	O
may	O
be	O
had	O
.	O
</s>
<s>
Scenes	O
are	O
lit	O
only	O
on	O
those	O
pixels	B-Algorithm
that	O
require	O
it	O
,	O
and	O
only	O
to	O
the	O
amount	O
of	O
brightness	O
they	O
require	O
.	O
</s>
<s>
SEDs	O
are	O
also	O
much	O
less	O
complex	O
in	O
overall	O
terms	O
–	O
they	O
lack	O
the	O
active	B-General_Concept
matrix	I-General_Concept
layer	O
,	O
backlighting	O
section	O
,	O
color	O
filters	O
,	O
and	O
the	O
driver	O
electronics	O
that	O
adjust	O
for	O
various	O
disadvantages	O
in	O
the	O
LCD	O
shuttering	O
process	O
.	O
</s>
<s>
The	O
same	O
set	O
claims	O
to	O
offer	O
viewing	B-General_Concept
angles	I-General_Concept
of	O
178	O
degrees	O
,	O
but	O
the	O
useful	O
viewing	B-General_Concept
angles	I-General_Concept
are	O
much	O
narrower	O
,	O
and	O
beyond	O
that	O
,	O
both	O
color	O
gamut	O
and	O
contrast	O
ratio	O
changes	O
.	O
</s>
<s>
SEDs	O
are	O
very	O
closely	O
related	O
to	O
the	O
field	B-General_Concept
emission	I-General_Concept
display	I-General_Concept
(	O
FED	O
)	O
,	O
differing	O
only	O
in	O
the	O
details	O
of	O
the	O
emitter	O
.	O
</s>
<s>
FEDs	O
have	O
one	O
advantage	O
the	O
SED	O
does	O
not	O
offer	O
;	O
since	O
each	O
sub-pixel	O
has	O
hundreds	O
of	O
emitters	O
,	O
"	O
dead	O
"	O
emitters	O
can	O
be	O
corrected	O
by	O
applying	O
slightly	O
more	O
power	O
to	O
the	O
working	O
ones	O
.	O
</s>
<s>
In	O
theory	O
,	O
this	O
could	O
increase	O
yields	O
because	O
the	O
chance	O
of	O
a	O
pixel	B-Algorithm
being	O
completely	O
dead	O
is	O
very	O
low	O
,	O
and	O
the	O
chance	O
that	O
a	O
screen	O
has	O
many	O
dead	O
pixels	B-Algorithm
is	O
greatly	O
reduced	O
.	O
</s>
<s>
Among	O
these	O
were	O
the	O
SED	O
,	O
the	O
FED	O
,	O
and	O
the	O
organic	B-Device
light-emitting	I-Device
diode	I-Device
system	O
that	O
uses	O
printable	O
LEDs	O
.	O
</s>
<s>
In	O
October	O
2006	O
,	O
Toshiba	O
's	O
president	O
announced	O
the	O
company	O
plans	O
to	O
begin	O
full	O
production	O
of	O
55-inch	O
SED	B-General_Concept
TVs	I-General_Concept
in	O
July	O
2007	O
at	O
its	O
recently	O
built	O
SED	O
volume-production	O
facility	O
in	O
Himeji	O
.	O
</s>
<s>
In	O
December	O
2006	O
,	O
Toshiba	O
President	O
and	O
Chief	O
Executive	O
Atsutoshi	O
Nishida	O
said	O
Toshiba	O
was	O
on	O
track	O
to	O
mass-produce	O
SED	B-General_Concept
TV	I-General_Concept
sets	O
in	O
cooperation	O
with	O
Canon	O
by	O
2008	O
.	O
</s>
<s>
He	O
said	O
the	O
company	O
planned	O
to	O
start	O
small-output	O
production	O
in	O
the	O
fall	O
of	O
2007	O
,	O
but	O
they	O
do	O
not	O
expect	O
SED	B-General_Concept
displays	I-General_Concept
to	O
become	O
a	O
commodity	O
and	O
will	O
not	O
release	O
the	O
technology	O
to	O
the	O
consumer	O
market	O
because	O
of	O
its	O
expected	O
high	O
price	O
,	O
reserving	O
it	O
solely	O
for	O
professional	O
broadcasting	O
applications	O
.	O
</s>
<s>
Canon	O
also	O
had	O
an	O
ongoing	O
OLED	B-Device
development	O
process	O
that	O
started	O
in	O
the	O
midst	O
of	O
the	O
lawsuit	O
.	O
</s>
<s>
Canon	O
later	O
announced	O
that	O
they	O
were	O
purchasing	O
Tokki	O
Corp	O
,	O
a	O
maker	O
of	O
OLED	B-Device
fabrication	O
equipment	O
.	O
</s>
<s>
Canon	O
officially	O
announced	O
on	O
25	O
May	O
2010	O
the	O
end	O
of	O
the	O
development	O
of	O
SED	B-General_Concept
TVs	I-General_Concept
for	O
the	O
home	O
consumer	O
market	O
,	O
but	O
indicated	O
that	O
they	O
will	O
continue	O
development	O
for	O
commercial	O
applications	O
like	O
medical	O
equipment	O
.	O
</s>
<s>
On	O
18	O
August	O
2010	O
,	O
Canon	O
decided	O
to	O
liquidate	O
SED	O
Inc.	O
,	O
a	O
consolidated	O
subsidiary	O
of	O
Canon	O
Inc	O
.	O
developing	O
SED	O
technology	O
,	O
citing	O
difficulties	O
to	O
secure	O
appropriate	O
profitability	O
and	O
effectively	O
ending	O
hopes	O
to	O
one	O
day	O
see	O
SED	B-General_Concept
TVs	I-General_Concept
in	O
the	O
home	O
or	O
the	O
room	O
or	O
the	O
living	O
room	O
.	O
</s>
