<s>
An	O
image	B-Algorithm
sensor	I-Algorithm
or	O
imager	B-Algorithm
is	O
a	O
sensor	O
that	O
detects	O
and	O
conveys	O
information	O
used	O
to	O
form	O
an	O
image	O
.	O
</s>
<s>
Image	B-Algorithm
sensors	I-Algorithm
are	O
used	O
in	O
electronic	O
imaging	O
devices	O
of	O
both	O
analog	O
and	O
digital	O
types	O
,	O
which	O
include	O
digital	B-Device
cameras	I-Device
,	O
camera	B-Algorithm
modules	I-Algorithm
,	O
camera	O
phones	O
,	O
optical	O
mouse	O
devices	O
,	O
medical	B-Application
imaging	I-Application
equipment	O
,	O
night	O
vision	O
equipment	O
such	O
as	O
thermal	B-Algorithm
imaging	I-Algorithm
devices	O
,	O
radar	B-Application
,	O
sonar	B-Application
,	O
and	O
others	O
.	O
</s>
<s>
As	O
technology	O
changes	O
,	O
electronic	O
and	O
digital	B-Algorithm
imaging	I-Algorithm
tends	O
to	O
replace	O
chemical	O
and	O
analog	O
imaging	O
.	O
</s>
<s>
The	O
two	O
main	O
types	O
of	O
electronic	O
image	B-Algorithm
sensors	I-Algorithm
are	O
the	O
charge-coupled	B-Algorithm
device	I-Algorithm
(	O
CCD	B-Algorithm
)	O
and	O
the	O
active-pixel	B-Architecture
sensor	I-Architecture
(	O
CMOS	B-Architecture
sensor	I-Architecture
)	O
.	O
</s>
<s>
Both	O
CCD	B-Algorithm
and	O
CMOS	B-Architecture
sensors	I-Architecture
are	O
based	O
on	O
metal	B-Architecture
–	I-Architecture
oxide	I-Architecture
–	I-Architecture
semiconductor	I-Architecture
(	O
MOS	O
)	O
technology	O
,	O
with	O
CCDs	O
based	O
on	O
MOS	O
capacitors	O
and	O
CMOS	B-Architecture
sensors	I-Architecture
based	O
on	O
MOSFET	B-Architecture
(	O
MOS	O
field-effect	O
transistor	B-Application
)	O
amplifiers	O
.	O
</s>
<s>
The	O
two	O
main	O
types	O
of	O
digital	B-Algorithm
image	I-Algorithm
sensors	I-Algorithm
are	O
the	O
charge-coupled	B-Algorithm
device	I-Algorithm
(	O
CCD	B-Algorithm
)	O
and	O
the	O
active-pixel	B-Architecture
sensor	I-Architecture
(	O
CMOS	B-Architecture
sensor	I-Architecture
)	O
,	O
fabricated	B-Architecture
in	O
complementary	O
MOS	O
(	O
CMOS	B-Device
)	O
or	O
N-type	B-Algorithm
MOS	I-Algorithm
(	O
NMOS	B-Algorithm
or	O
Live	B-Algorithm
MOS	I-Algorithm
)	O
technologies	O
.	O
</s>
<s>
Both	O
CCD	B-Algorithm
and	O
CMOS	B-Architecture
sensors	I-Architecture
are	O
based	O
on	O
the	O
MOS	B-Architecture
technology	I-Architecture
,	O
with	O
MOS	O
capacitors	O
being	O
the	O
building	O
blocks	O
of	O
a	O
CCD	B-Algorithm
,	O
and	O
MOSFET	B-Architecture
amplifiers	O
being	O
the	O
building	O
blocks	O
of	O
a	O
CMOS	B-Architecture
sensor	I-Architecture
.	O
</s>
<s>
Cameras	O
integrated	O
in	O
small	O
consumer	O
products	O
generally	O
use	O
CMOS	B-Architecture
sensors	I-Architecture
,	O
which	O
are	O
usually	O
cheaper	O
and	O
have	O
lower	O
power	O
consumption	O
in	O
battery	O
powered	O
devices	O
than	O
CCDs	O
.	O
</s>
<s>
CCD	B-Algorithm
sensors	I-Algorithm
are	O
used	O
for	O
high	O
end	O
broadcast	O
quality	O
video	O
cameras	O
,	O
and	O
CMOS	B-Architecture
sensors	I-Architecture
dominate	O
in	O
still	O
photography	O
and	O
consumer	O
goods	O
where	O
overall	O
cost	O
is	O
a	O
major	O
concern	O
.	O
</s>
<s>
Each	O
cell	O
of	O
a	O
CCD	B-Algorithm
image	B-Algorithm
sensor	I-Algorithm
is	O
an	O
analog	O
device	O
.	O
</s>
<s>
A	O
CMOS	B-Architecture
image	I-Architecture
sensor	I-Architecture
has	O
an	O
amplifier	O
for	O
each	O
pixel	O
compared	O
to	O
the	O
few	O
amplifiers	O
of	O
a	O
CCD	B-Algorithm
.	O
</s>
<s>
This	O
results	O
in	O
less	O
area	O
for	O
the	O
capture	O
of	O
photons	B-Application
than	O
a	O
CCD	B-Algorithm
,	O
but	O
this	O
problem	O
has	O
been	O
overcome	O
by	O
using	O
microlenses	O
in	O
front	O
of	O
each	O
photodiode	O
,	O
which	O
focus	O
light	O
into	O
the	O
photodiode	O
that	O
would	O
have	O
otherwise	O
hit	O
the	O
amplifier	O
and	O
not	O
been	O
detected	O
.	O
</s>
<s>
Some	O
CMOS	B-Device
imaging	B-Algorithm
sensors	I-Algorithm
also	O
use	O
Back-side	B-Algorithm
illumination	I-Algorithm
to	O
increase	O
the	O
number	O
of	O
photons	B-Application
that	O
hit	O
the	O
photodiode	O
.	O
</s>
<s>
CMOS	B-Architecture
sensors	I-Architecture
can	O
potentially	O
be	O
implemented	O
with	O
fewer	O
components	O
,	O
use	O
less	O
power	O
,	O
and/or	O
provide	O
faster	O
readout	O
than	O
CCD	B-Algorithm
sensors	I-Algorithm
.	O
</s>
<s>
Another	O
design	O
,	O
a	O
hybrid	O
CCD/CMOS	O
architecture	O
(	O
sold	O
under	O
the	O
name	O
"	O
sCMOS	O
"	O
)	O
consists	O
of	O
CMOS	B-Device
readout	O
integrated	O
circuits	O
(	O
ROICs	O
)	O
that	O
are	O
bump	O
bonded	O
to	O
a	O
CCD	B-Algorithm
imaging	I-Algorithm
substrate	O
–	O
a	O
technology	O
that	O
was	O
developed	O
for	O
infrared	O
staring	B-Algorithm
arrays	I-Algorithm
and	O
has	O
been	O
adapted	O
to	O
silicon-based	O
detector	O
technology	O
.	O
</s>
<s>
Another	O
approach	O
is	O
to	O
utilize	O
the	O
very	O
fine	O
dimensions	O
available	O
in	O
modern	O
CMOS	B-Device
technology	O
to	O
implement	O
a	O
CCD	B-Algorithm
like	O
structure	O
entirely	O
in	O
CMOS	B-Device
technology	O
:	O
such	O
structures	O
can	O
be	O
achieved	O
by	O
separating	O
individual	O
poly-silicon	O
gates	O
by	O
a	O
very	O
small	O
gap	O
;	O
though	O
still	O
a	O
product	O
of	O
research	O
hybrid	O
sensors	O
can	O
potentially	O
harness	O
the	O
benefits	O
of	O
both	O
CCD	B-Algorithm
and	O
CMOS	B-Architecture
imagers	I-Architecture
.	O
</s>
<s>
There	O
are	O
many	O
parameters	O
that	O
can	O
be	O
used	O
to	O
evaluate	O
the	O
performance	O
of	O
an	O
image	B-Algorithm
sensor	I-Algorithm
,	O
including	O
dynamic	O
range	O
,	O
signal-to-noise	O
ratio	O
,	O
and	O
low-light	O
sensitivity	O
.	O
</s>
<s>
It	O
’s	O
because	O
in	O
a	O
given	O
integration	O
(	O
exposure	O
)	O
time	O
,	O
more	O
photons	B-Application
hit	O
the	O
pixel	O
with	O
larger	O
area	O
.	O
</s>
<s>
Exposure	O
time	O
of	O
image	B-Algorithm
sensors	I-Algorithm
is	O
generally	O
controlled	O
by	O
either	O
a	O
conventional	O
mechanical	O
shutter	O
,	O
as	O
in	O
film	O
cameras	O
,	O
or	O
by	O
an	O
electronic	O
shutter	O
.	O
</s>
<s>
Electronic	O
shuttering	O
can	O
be	O
"	O
global	O
,	O
"	O
in	O
which	O
case	O
the	O
entire	O
image	B-Algorithm
sensor	I-Algorithm
area	O
's	O
accumulation	O
of	O
photoelectrons	O
starts	O
and	O
stops	O
simultaneously	O
,	O
or	O
"	O
rolling	O
"	O
in	O
which	O
case	O
the	O
exposure	O
interval	O
of	O
each	O
row	O
immediate	O
precedes	O
that	O
row	O
's	O
readout	O
,	O
in	O
a	O
process	O
that	O
"	O
rolls	O
"	O
across	O
the	O
image	O
frame	O
(	O
typically	O
from	O
top	O
to	O
bottom	O
in	O
landscape	O
format	O
)	O
.	O
</s>
<s>
There	O
are	O
several	O
main	O
types	O
of	O
color	B-Algorithm
image	I-Algorithm
sensors	O
,	O
differing	O
by	O
the	O
type	O
of	O
color-separation	O
mechanism	O
:	O
</s>
<s>
Integral	O
color	O
sensors	O
use	O
a	O
color	B-Algorithm
filter	I-Algorithm
array	I-Algorithm
fabricated	B-Architecture
on	O
top	O
of	O
a	O
single	O
monochrome	O
CCD	B-Algorithm
or	O
CMOS	B-Architecture
image	I-Architecture
sensor	I-Architecture
.	O
</s>
<s>
The	O
most	O
common	O
color	B-Algorithm
filter	I-Algorithm
array	I-Algorithm
pattern	O
,	O
the	O
Bayer	B-Algorithm
pattern	I-Algorithm
,	O
uses	O
a	O
checkerboard	O
arrangement	O
of	O
two	O
green	O
pixels	O
for	O
each	O
red	O
and	O
blue	O
pixel	O
,	O
although	O
many	O
other	O
color	O
filter	O
patterns	O
have	O
been	O
developed	O
,	O
including	O
patterns	O
using	O
cyan	O
,	O
magenta	O
,	O
yellow	O
,	O
and	O
white	O
pixels	O
.	O
</s>
<s>
Integral	O
color	O
sensors	O
were	O
initially	O
manufactured	O
by	O
transferring	O
colored	O
dyes	O
through	O
photoresist	O
windows	O
onto	O
a	O
polymer	O
receiving	O
layer	O
coated	O
on	O
top	O
of	O
a	O
monochrome	O
CCD	B-Algorithm
sensor	I-Algorithm
.	O
</s>
<s>
This	O
processing	O
is	O
also	O
referred	O
to	O
as	O
demosaicing	B-Algorithm
or	O
de-bayering	O
.	O
</s>
<s>
Foveon	B-Algorithm
X3	I-Algorithm
sensor	I-Algorithm
,	O
using	O
an	O
array	O
of	O
layered	O
pixel	O
sensors	O
,	O
separating	O
light	O
via	O
the	O
inherent	O
wavelength-dependent	O
absorption	O
property	O
of	O
silicon	O
,	O
such	O
that	O
every	O
location	O
senses	O
all	O
three	O
color	O
channels	O
.	O
</s>
<s>
3CCD	B-Algorithm
,	O
using	O
three	O
discrete	O
image	B-Algorithm
sensors	I-Algorithm
,	O
with	O
the	O
color	O
separation	O
done	O
by	O
a	O
dichroic	O
prism	O
.	O
</s>
<s>
Because	O
each	O
sensor	O
is	O
equally	O
sensitive	O
within	O
its	O
passband	B-Algorithm
,	O
and	O
at	O
full	O
resolution	O
,	O
3-CCD	O
sensors	O
produce	O
better	O
color	O
quality	O
and	O
better	O
low	O
light	O
performance	O
.	O
</s>
<s>
Special	O
sensors	O
are	O
used	O
in	O
various	O
applications	O
such	O
as	O
thermography	B-Algorithm
,	O
creation	O
of	O
multi-spectral	O
images	O
,	O
video	O
laryngoscopes	O
,	O
gamma	O
cameras	O
,	O
sensor	O
arrays	O
for	O
x-rays	B-Library
,	O
and	O
other	O
highly	O
sensitive	O
arrays	O
for	O
astronomy	O
.	O
</s>
<s>
While	O
in	O
general	O
,	O
digital	B-Device
cameras	I-Device
use	O
a	O
flat	O
sensor	O
,	O
Sony	O
prototyped	O
a	O
curved	O
sensor	O
in	O
2014	O
to	O
reduce/eliminate	O
Petzval	O
field	O
curvature	O
that	O
occurs	O
with	O
a	O
flat	O
sensor	O
.	O
</s>
<s>
By	O
the	O
early	O
1990s	O
,	O
they	O
had	O
been	O
replaced	O
by	O
modern	O
solid-state	O
CCD	B-Algorithm
image	B-Algorithm
sensors	I-Algorithm
.	O
</s>
<s>
The	O
basis	O
for	O
modern	O
solid-state	O
image	B-Algorithm
sensors	I-Algorithm
is	O
MOS	B-Architecture
technology	I-Architecture
,	O
which	O
originates	O
from	O
the	O
invention	O
of	O
the	O
MOSFET	B-Architecture
by	O
Mohamed	O
M	O
.	O
Atalla	O
and	O
Dawon	O
Kahng	O
at	O
Bell	O
Labs	O
in	O
1959	O
.	O
</s>
<s>
Later	O
research	O
on	O
MOS	B-Architecture
technology	I-Architecture
led	O
to	O
the	O
development	O
of	O
solid-state	O
semiconductor	O
image	B-Algorithm
sensors	I-Algorithm
,	O
including	O
the	O
charge-coupled	B-Algorithm
device	I-Algorithm
(	O
CCD	B-Algorithm
)	O
and	O
later	O
the	O
active-pixel	B-Architecture
sensor	I-Architecture
(	O
CMOS	B-Architecture
sensor	I-Architecture
)	O
.	O
</s>
<s>
The	O
passive-pixel	O
sensor	O
(	O
PPS	O
)	O
was	O
the	O
precursor	O
to	O
the	O
active-pixel	B-Architecture
sensor	I-Architecture
(	O
APS	O
)	O
.	O
</s>
<s>
A	O
PPS	O
consists	O
of	O
passive	O
pixels	O
which	O
are	O
read	O
out	O
without	O
amplification	O
,	O
with	O
each	O
pixel	O
consisting	O
of	O
a	O
photodiode	O
and	O
a	O
MOSFET	B-Architecture
switch	O
.	O
</s>
<s>
It	O
is	O
a	O
type	O
of	O
photodiode	O
array	O
,	O
with	O
pixels	O
containing	O
a	O
p-n	O
junction	O
,	O
integrated	O
capacitor	O
,	O
and	O
MOSFETs	B-Architecture
as	O
selection	O
transistors	B-Application
.	O
</s>
<s>
These	O
early	O
photodiode	O
arrays	O
were	O
complex	O
and	O
impractical	O
,	O
requiring	O
selection	O
transistors	B-Application
to	O
be	O
fabricated	B-Architecture
within	O
each	O
pixel	O
,	O
along	O
with	O
on-chip	O
multiplexer	B-Protocol
circuits	O
.	O
</s>
<s>
Correlated	O
double	O
sampling	O
(	O
CDS	O
)	O
could	O
also	O
not	O
be	O
used	O
with	O
a	O
photodiode	O
array	O
without	O
external	O
memory	B-General_Concept
.	O
</s>
<s>
In	O
June	O
2022	O
,	O
Samsung	O
Electronics	O
announced	O
that	O
it	O
had	O
created	O
a	O
200	O
million	O
pixel	O
image	B-Algorithm
sensor	I-Algorithm
.	O
</s>
<s>
The	O
charge-coupled	B-Algorithm
device	I-Algorithm
(	O
CCD	B-Algorithm
)	O
was	O
invented	O
by	O
Willard	O
S	O
.	O
Boyle	O
and	O
George	O
E	O
.	O
Smith	O
at	O
Bell	O
Labs	O
in	O
1969	O
.	O
</s>
<s>
While	O
researching	O
MOS	B-Architecture
technology	I-Architecture
,	O
they	O
realized	O
that	O
an	O
electric	O
charge	O
was	O
the	O
analogy	O
of	O
the	O
magnetic	O
bubble	O
and	O
that	O
it	O
could	O
be	O
stored	O
on	O
a	O
tiny	O
MOS	O
capacitor	O
.	O
</s>
<s>
As	O
it	O
was	O
fairly	O
straightforward	O
to	O
fabricate	B-Architecture
a	O
series	O
of	O
MOS	O
capacitors	O
in	O
a	O
row	O
,	O
they	O
connected	O
a	O
suitable	O
voltage	O
to	O
them	O
so	O
that	O
the	O
charge	O
could	O
be	O
stepped	O
along	O
from	O
one	O
to	O
the	O
next	O
.	O
</s>
<s>
The	O
CCD	B-Algorithm
is	O
a	O
semiconductor	O
circuit	O
that	O
was	O
later	O
used	O
in	O
the	O
first	O
digital	O
video	O
cameras	O
for	O
television	O
broadcasting	O
.	O
</s>
<s>
Early	O
CCD	B-Algorithm
sensors	I-Algorithm
suffered	O
from	O
shutter	O
lag	O
.	O
</s>
<s>
In	O
1987	O
,	O
the	O
PPD	O
began	O
to	O
be	O
incorporated	O
into	O
most	O
CCD	B-Algorithm
devices	O
,	O
becoming	O
a	O
fixture	O
in	O
consumer	O
electronic	O
video	O
cameras	O
and	O
then	O
digital	B-Device
still	I-Device
cameras	I-Device
.	O
</s>
<s>
Since	O
then	O
,	O
the	O
PPD	O
has	O
been	O
used	O
in	O
nearly	O
all	O
CCD	B-Algorithm
sensors	I-Algorithm
and	O
then	O
CMOS	B-Architecture
sensors	I-Architecture
.	O
</s>
<s>
The	O
NMOS	B-Algorithm
active-pixel	B-Architecture
sensor	I-Architecture
(	O
APS	O
)	O
was	O
invented	O
by	O
Olympus	O
in	O
Japan	O
during	O
the	O
mid-1980s	O
.	O
</s>
<s>
This	O
was	O
enabled	O
by	O
advances	O
in	O
MOS	O
semiconductor	B-Architecture
device	I-Architecture
fabrication	I-Architecture
,	O
with	O
MOSFET	B-Architecture
scaling	O
reaching	O
smaller	O
micron	B-Algorithm
and	I-Algorithm
then	I-Algorithm
sub-micron	I-Algorithm
levels	O
.	O
</s>
<s>
The	O
first	O
NMOS	B-Algorithm
APS	O
was	O
fabricated	B-Architecture
by	O
Tsutomu	O
Nakamura	O
's	O
team	O
at	O
Olympus	O
in	O
1985	O
.	O
</s>
<s>
The	O
CMOS	B-Device
active-pixel	B-Architecture
sensor	I-Architecture
(	O
CMOS	B-Architecture
sensor	I-Architecture
)	O
was	O
later	O
improved	O
by	O
a	O
group	O
of	O
scientists	O
at	O
the	O
NASA	O
Jet	O
Propulsion	O
Laboratory	O
in	O
1993	O
.	O
</s>
<s>
By	O
2007	O
,	O
sales	O
of	O
CMOS	B-Architecture
sensors	I-Architecture
had	O
surpassed	O
CCD	B-Algorithm
sensors	I-Algorithm
.	O
</s>
<s>
By	O
the	O
2010s	O
,	O
CMOS	B-Architecture
sensors	I-Architecture
largely	O
displaced	O
CCD	B-Algorithm
sensors	I-Algorithm
in	O
all	O
new	O
applications	O
.	O
</s>
<s>
The	O
first	O
commercial	O
digital	B-Device
camera	I-Device
,	O
the	O
Cromemco	B-Algorithm
Cyclops	I-Algorithm
in	O
1975	O
,	O
used	O
a	O
32×32	O
MOS	O
image	B-Algorithm
sensor	I-Algorithm
.	O
</s>
<s>
It	O
was	O
a	O
modified	O
MOS	O
dynamic	O
RAM	B-Architecture
(	O
DRAM	O
)	O
memory	B-Architecture
chip	I-Architecture
.	O
</s>
<s>
MOS	O
image	B-Algorithm
sensors	I-Algorithm
are	O
widely	O
used	O
in	O
optical	O
mouse	O
technology	O
.	O
</s>
<s>
The	O
first	O
optical	O
mouse	O
,	O
invented	O
by	O
Richard	O
F	O
.	O
Lyon	O
at	O
Xerox	O
in	O
1980	O
,	O
used	O
a	O
5µm	O
NMOS	B-Algorithm
integrated	O
circuit	O
sensor	O
chip	O
.	O
</s>
<s>
Since	O
the	O
first	O
commercial	O
optical	O
mouse	O
,	O
the	O
IntelliMouse	B-Device
introduced	O
in	O
1999	O
,	O
most	O
optical	O
mouse	O
devices	O
use	O
CMOS	B-Architecture
sensors	I-Architecture
.	O
</s>
<s>
In	O
February	O
2018	O
,	O
researchers	O
at	O
Dartmouth	O
College	O
announced	O
a	O
new	O
image	O
sensing	O
technology	O
that	O
the	O
researchers	O
call	O
QIS	O
,	O
for	O
Quanta	O
Image	B-Algorithm
Sensor	I-Algorithm
.	O
</s>
<s>
Each	O
jot	O
can	O
detect	O
a	O
single	O
particle	O
of	O
light	O
,	O
called	O
a	O
photon	B-Application
.	O
</s>
