<s>
ISO	B-General_Concept
13406-2	I-General_Concept
is	O
an	O
ISO	O
standard	O
,	O
with	O
the	O
full	O
title	O
"	O
Ergonomic	O
requirements	O
for	O
work	O
with	O
visual	O
displays	O
based	O
on	O
flat	O
panels	O
--	O
Part	O
2	O
:	O
Ergonomic	O
requirements	O
for	O
flat	O
panel	O
displays	O
"	O
.	O
</s>
<s>
It	O
is	O
best	O
known	O
to	O
end	O
consumers	O
for	O
defining	O
a	O
series	O
of	O
flat-panel	O
display	O
"	O
classes	O
"	O
with	O
different	O
numbers	O
of	O
permitted	O
defects	O
(	O
or	O
"	O
dead	B-General_Concept
pixels	I-General_Concept
"	O
)	O
.	O
</s>
<s>
ISO	B-General_Concept
13406-2	I-General_Concept
also	O
provides	O
a	O
classification	O
of	O
Viewing	B-Device
Direction	I-Device
Range	O
Classes	O
and	O
Reflection	O
Classes	O
.	O
</s>
<s>
The	O
standard	O
lists	O
four	O
classes	O
of	O
devices	O
,	O
where	O
a	O
device	O
of	O
a	O
specified	O
class	O
may	O
contain	O
a	O
certain	O
maximum	O
number	O
of	O
defective	B-General_Concept
pixels	I-General_Concept
.	O
</s>
<s>
Three	O
distinct	O
types	O
of	O
defective	B-General_Concept
pixels	I-General_Concept
are	O
described	O
:	O
</s>
<s>
,	O
most	O
manufacturers	O
specify	O
their	O
products	O
as	O
Pixel	B-General_Concept
Fault	I-General_Concept
Class	O
II	O
.	O
</s>
