<s>
Duplex	B-Device
scanning	I-Device
is	O
a	O
feature	O
of	O
some	O
computer	B-Application
scanners	I-Application
,	O
and	O
multifunction	O
printers	O
(	O
MFPs	O
)	O
that	O
support	O
duplex	O
printing	O
.	O
</s>
<s>
A	O
duplex	O
scanner	O
can	O
automatically	O
scan	B-Application
a	I-Application
sheet	I-Application
of	I-Application
paper	I-Application
on	O
both	O
sides	O
.	O
</s>
<s>
Duplex	B-Device
scanning	I-Device
is	O
usually	O
implemented	O
on	O
multifunction	O
printers	O
using	O
a	O
Reversing	B-Device
Automatic	I-Device
Document	I-Device
Feeder	I-Device
(	O
RADF	B-Device
)	O
,	O
which	O
removes	O
,	O
reverses	O
,	O
and	O
re-feeds	O
the	O
document	O
after	O
scanning	O
one	O
side	O
.	O
</s>
<s>
Duplex	B-Device
scanning	I-Device
is	O
achieved	O
on	O
scanners	O
by	O
either	O
RADF	B-Device
or	O
by	O
single	O
pass	O
duplex	B-Device
scanning	I-Device
using	O
two	O
cameras	O
,	O
one	O
for	O
each	O
side	O
of	O
document	O
;	O
two-camera	O
scanners	O
scan	O
twice	O
as	O
fast	O
as	O
a	O
similar	O
two-pass	O
scanner	O
.	O
</s>
