<s>
In	O
computing	O
,	O
an	O
input	B-Device
device	I-Device
is	O
a	O
piece	O
of	O
equipment	O
used	O
to	O
provide	O
data	O
and	O
control	O
signals	O
to	O
an	O
information	O
processing	O
system	O
,	O
such	O
as	O
a	O
computer	O
or	O
information	O
appliance	O
.	O
</s>
<s>
Examples	O
of	O
input	B-Device
devices	I-Device
include	O
keyboards	B-Device
,	O
mouse	B-Device
,	O
scanners	O
,	O
cameras	O
,	O
joysticks	B-Device
,	O
and	O
microphones	B-Application
.	O
</s>
<s>
Input	B-Device
devices	I-Device
can	O
be	O
categorized	O
based	O
on	O
:	O
</s>
<s>
modality	B-General_Concept
of	O
input	O
(	O
e.g.	O
,	O
mechanical	O
motion	O
,	O
audio	O
,	O
visual	O
,	O
etc	O
.	O
)	O
</s>
<s>
A	O
keyboard	B-Device
is	O
a	O
human	B-General_Concept
interface	I-General_Concept
device	I-General_Concept
which	O
is	O
represented	O
as	O
a	O
layout	O
of	O
buttons	O
.	O
</s>
<s>
It	O
acts	O
as	O
the	O
main	O
text	B-Device
entry	I-Device
interface	I-Device
for	O
most	O
users	O
.	O
</s>
<s>
Keyboards	B-Device
are	O
available	O
in	O
many	O
form	O
factors	O
,	O
depending	O
on	O
the	O
use	O
case	O
.	O
</s>
<s>
Standard	O
keyboards	B-Device
can	O
be	O
categorized	O
by	O
its	O
size	O
and	O
number	O
of	O
keys	O
,	O
and	O
the	O
type	O
of	O
switch	O
it	O
employs	O
.	O
</s>
<s>
Other	O
keyboards	B-Device
cater	O
to	O
specific	O
use	O
cases	O
,	O
such	O
as	O
a	O
numeric	B-Device
keypad	I-Device
or	O
a	O
keyer	B-Device
.	O
</s>
<s>
Desktop	O
keyboards	B-Device
are	O
typically	O
large	O
,	O
often	O
have	O
full	O
key	O
travel	O
distance	O
,	O
and	O
features	O
such	O
as	O
multimedia	O
keys	O
and	O
a	O
numeric	B-Device
keypad	I-Device
.	O
</s>
<s>
Keyboards	B-Device
on	O
laptops	O
and	O
tablets	O
typically	O
compromise	O
on	O
comfort	O
to	O
achieve	O
a	O
thin	O
figure	O
.	O
</s>
<s>
There	O
are	O
various	O
switch	O
technologies	O
used	O
in	O
modern	O
keyboards	B-Device
,	O
such	O
as	O
mechanical	O
switches	O
(	O
which	O
use	O
springs	O
)	O
,	O
scissor	O
switches	O
(	O
usually	O
found	O
on	O
a	O
laptop	O
keyboard	B-Device
)	O
,	O
or	O
a	O
membrane	O
.	O
</s>
<s>
Other	O
keyboards	B-Device
do	O
not	O
have	O
physical	O
keys	O
,	O
such	O
as	O
a	O
virtual	B-Device
keyboard	I-Device
,	O
or	O
a	O
projection	B-Device
keyboard	I-Device
.	O
</s>
<s>
Ergonomic	B-Device
keyboard	I-Device
A	O
keyboard	B-Device
placing	O
design	O
emphasis	O
on	O
ergonomics	O
and	O
comfort	O
.	O
</s>
<s>
Chorded	B-Device
keyboard	I-Device
A	O
keyboard	B-Device
used	O
by	O
pressing	O
several	O
keys	O
together	O
.	O
</s>
<s>
Thumb	B-Device
keyboard	I-Device
A	O
miniature	O
keyboard	B-Device
found	O
in	O
PDAs	B-Application
and	O
mobile	O
phones	O
.	O
</s>
<s>
Keyer	B-Device
A	O
chorded	B-Device
keyboard	I-Device
without	O
the	O
board	O
.	O
</s>
<s>
Numeric	B-Device
keypad	I-Device
While	O
some	O
keyboards	B-Device
include	O
a	O
them	O
(	O
commonly	O
found	O
at	O
the	O
right	O
side	O
)	O
,	O
numeric	B-Device
keypads	I-Device
can	O
be	O
found	O
as	O
independent	O
devices	O
.	O
</s>
<s>
It	O
is	O
commonly	O
used	O
as	O
a	O
simple	O
and	O
intuitive	O
way	O
to	O
select	O
items	O
on	O
a	O
computer	B-Device
screen	I-Device
on	O
a	O
graphical	B-Application
user	I-Application
interface	I-Application
(	O
GUI	B-Application
)	O
,	O
either	O
by	O
moving	O
a	O
mouse	B-Device
pointer	I-Device
,	O
or	O
,	O
in	O
the	O
case	O
of	O
a	O
touch	B-Device
screen	I-Device
,	O
by	O
physically	O
touching	O
the	O
item	O
on	O
screen	O
.	O
</s>
<s>
Common	O
pointing	O
devices	O
include	O
mice	O
,	O
touchpads	B-Application
,	O
and	O
touch	B-Device
screens	I-Device
.	O
</s>
<s>
Whereas	O
mice	O
operate	O
by	O
detecting	O
their	O
displacement	O
on	O
a	O
surface	O
,	O
analog	O
devices	O
,	O
such	O
as	O
3D	O
mice	O
,	O
joysticks	B-Device
,	O
or	O
pointing	O
sticks	O
,	O
function	O
by	O
reporting	O
their	O
angle	O
of	O
deflection	O
.	O
</s>
<s>
pointing	O
is	O
done	O
in	O
the	O
space	O
where	O
visual	O
feedback	O
or	O
the	O
pointer	B-Device
appears	O
.	O
</s>
<s>
Touchscreens	B-Device
and	O
light	B-Device
pens	I-Device
involve	O
direct	O
input	O
.	O
</s>
<s>
Examples	O
involving	O
indirect	O
input	O
include	O
the	O
mouse	B-Device
and	O
trackball	B-Device
.	O
</s>
<s>
For	O
example	O
,	O
digitizing	O
graphics	B-Device
tablets	I-Device
that	O
do	O
not	O
have	O
an	O
embedded	O
screen	O
involve	O
indirect	O
input	O
and	O
sense	O
absolute	O
positions	O
and	O
are	O
often	O
run	O
in	O
an	O
absolute	O
input	O
mode	O
,	O
but	O
they	O
may	O
also	O
be	O
set	O
up	O
to	O
simulate	O
a	O
relative	O
input	O
mode	O
like	O
that	O
of	O
a	O
touchpad	B-Application
,	O
where	O
the	O
stylus	O
or	O
puck	O
can	O
be	O
lifted	O
and	O
repositioned	O
.	O
</s>
<s>
Embedded	O
LCD	O
tablets	O
,	O
which	O
are	O
also	O
referred	O
to	O
as	O
graphics	B-Device
tablet	I-Device
monitors	O
,	O
are	O
the	O
extension	O
of	O
digitizing	O
graphics	B-Device
tablets	I-Device
.	O
</s>
<s>
mouse	B-Device
A	O
hand-held	B-Application
pointing	O
device	O
that	O
is	O
moved	O
across	O
a	O
surface	O
.	O
</s>
<s>
touchpad	B-Application
or	O
trackpad	O
A	O
flat	O
surface	O
operated	O
by	O
moving	O
a	O
finger	O
across	O
its	O
surface	O
.	O
</s>
<s>
touch	B-Device
screen	I-Device
A	O
layer	O
placed	O
over	O
a	O
computer	B-Device
screen	I-Device
,	O
used	O
by	O
physically	O
touching	O
it	O
.	O
</s>
<s>
trackball	B-Device
Similar	O
to	O
a	O
mouse	B-Device
,	O
a	O
trackball	B-Device
has	O
a	O
ball	O
held	O
by	O
a	O
socket	O
.	O
</s>
<s>
Instead	O
of	O
moving	O
the	O
mouse	B-Device
,	O
the	O
user	O
rolls	O
the	O
ball	O
with	O
their	O
finger	O
.	O
</s>
<s>
graphics	B-Device
tablet	I-Device
,	O
digitizer	O
,	O
or	O
drawing	B-Device
tablet	I-Device
A	O
flat	O
surface	O
on	O
which	O
a	O
pen	O
is	O
used	O
,	O
usually	O
to	O
draw	O
images	O
or	O
capture	O
signatures	O
.	O
</s>
<s>
A	O
sensor	O
is	O
an	O
input	B-Device
device	I-Device
which	O
produces	O
data	O
based	O
on	O
physical	O
properties	O
.	O
</s>
<s>
Sensors	O
are	O
commonly	O
found	O
in	O
mobile	B-Application
devices	I-Application
to	O
detect	O
their	O
physical	O
orientation	O
and	O
acceleration	O
,	O
but	O
may	O
also	O
be	O
found	O
in	O
desktop	B-Device
computers	I-Device
in	O
the	O
form	O
of	O
a	O
thermometer	O
used	O
to	O
monitor	O
system	O
temperature	O
.	O
</s>
<s>
Gyroscope	B-Application
Detects	O
spatial	O
orientation	O
.	O
</s>
<s>
Proximity	B-Device
sensor	I-Device
Detects	O
whether	O
an	O
object	O
is	O
in	O
proximity	O
.	O
</s>
<s>
Ultrasonic	B-Algorithm
transducer	I-Algorithm
Detects	O
movement	O
and	O
range	O
of	O
objects	O
using	O
ultrasound	B-Application
.	O
</s>
<s>
These	O
kinds	O
of	O
devices	O
are	O
typically	O
used	O
in	O
virtual	B-Application
reality	I-Application
systems	O
(	O
CAVEs	O
)	O
,	O
where	O
input	O
that	O
registers	O
six	O
degrees	O
of	O
freedom	O
is	O
required	O
.	O
</s>
<s>
Input	B-Device
devices	I-Device
,	O
such	O
as	O
buttons	O
and	O
joysticks	B-Device
,	O
can	O
be	O
combined	O
on	O
a	O
single	O
physical	O
device	O
that	O
could	O
be	O
thought	O
of	O
as	O
a	O
composite	O
device	O
.	O
</s>
<s>
Joystick	B-Device
Consists	O
of	O
a	O
stick	O
pivoting	O
on	O
a	O
stationary	O
base	O
.	O
</s>
<s>
Gamepad	B-Device
,	O
or	O
joypad	O
Hand	B-Application
held	I-Application
device	O
often	O
used	O
to	O
play	O
modern	O
video	O
games	O
.	O
</s>
<s>
Paddle	B-Device
A	O
paddle	B-Device
could	O
be	O
a	O
game	O
controller	O
consisting	O
of	O
a	O
dial	O
and	O
a	O
button	O
,	O
or	O
an	O
input	B-Device
device	I-Device
such	O
as	O
a	O
Griffin	B-Device
PowerMate	I-Device
or	O
a	O
Microsoft	O
Surface	O
Dial	O
.	O
</s>
<s>
Racing	B-Application
wheel	I-Application
An	O
imitation	O
steering	O
wheel	O
that	O
can	O
be	O
used	O
to	O
play	O
racing	O
video	O
games	O
.	O
</s>
<s>
Wii	B-Device
Remote	I-Device
A	O
remote	B-Protocol
control	I-Protocol
used	O
with	O
the	B-Operating_System
Nintendo	I-Operating_System
Wii	I-Operating_System
video	O
game	O
console	O
which	O
integrates	O
an	O
accelerometer	O
and	O
pointing	O
capabilities	O
.	O
</s>
<s>
Video	O
input	B-Device
devices	I-Device
are	O
used	O
to	O
digitize	O
images	O
or	O
video	O
from	O
the	O
outside	O
world	O
into	O
the	O
computer	O
.	O
</s>
<s>
Many	O
video	O
input	B-Device
devices	I-Device
use	O
a	O
camera	B-Algorithm
sensor	I-Algorithm
.	O
</s>
<s>
Voice	O
input	B-Device
devices	I-Device
are	O
used	O
to	O
capture	O
sound	O
.	O
</s>
<s>
In	O
some	O
cases	O
,	O
an	O
audio	O
output	B-Device
device	I-Device
can	O
be	O
used	O
as	O
an	O
input	B-Device
device	I-Device
,	O
in	O
order	O
to	O
capture	O
produced	O
sound	O
.	O
</s>
<s>
Audio	O
input	B-Device
devices	I-Device
allow	O
a	O
user	O
to	O
send	O
audio	O
info	O
to	O
a	O
computer	O
for	O
processing	O
,	O
recording	O
,	O
or	O
carrying	O
out	O
commands	O
.	O
</s>
<s>
Devices	O
such	O
as	O
microphones	B-Application
allow	O
users	O
to	O
speak	O
to	O
the	O
computer	O
in	O
order	O
to	O
record	O
a	O
voice	O
message	O
or	O
navigate	O
software	O
.	O
</s>
<s>
Aside	O
from	O
recording	O
,	O
audio	O
input	B-Device
devices	I-Device
are	O
also	O
used	O
with	O
speech	B-Application
recognition	I-Application
software	I-Application
.	O
</s>
<s>
Punched	B-Architecture
cards	I-Architecture
and	O
punched	O
tapes	O
were	O
much	O
used	O
in	O
the	O
20th	O
century	O
.	O
</s>
