<s>
A	O
back-illuminated	B-Algorithm
sensor	I-Algorithm
,	O
also	O
known	O
as	O
backside	B-Algorithm
illumination	I-Algorithm
(	O
BI	O
)	O
sensor	O
,	O
is	O
a	O
type	O
of	O
digital	B-Algorithm
image	I-Algorithm
sensor	I-Algorithm
that	O
uses	O
a	O
novel	O
arrangement	O
of	O
the	O
imaging	O
elements	O
to	O
increase	O
the	O
amount	O
of	O
light	O
captured	O
and	O
thereby	O
improve	O
low-light	O
performance	O
.	O
</s>
<s>
Sony	O
was	O
the	O
first	O
to	O
reduce	O
these	O
problems	O
and	O
their	O
costs	O
sufficiently	O
to	O
introduce	O
a	O
5-megapixel	O
1.75µm	O
BI	O
CMOS	B-Architecture
sensor	I-Architecture
at	O
general	O
consumer	O
prices	O
in	O
2009	O
.	O
</s>
<s>
BI	O
sensors	O
from	O
OmniVision	O
Technologies	O
have	O
since	O
been	O
used	O
in	O
consumer	O
electronics	O
from	O
other	O
manufacturers	O
as	O
in	O
the	O
HTC	B-Application
EVO	I-Application
4G	I-Application
Android	O
smartphone	O
,	O
and	O
as	O
a	O
major	O
selling	O
point	O
for	O
the	O
camera	O
in	O
Apple	O
's	O
iPhone	B-Operating_System
4	I-Operating_System
.	O
</s>
<s>
A	O
traditional	O
,	O
front-illuminated	O
digital	B-Device
camera	I-Device
is	O
constructed	O
in	O
a	O
fashion	O
similar	O
to	O
the	O
human	O
eye	O
,	O
with	O
a	O
lens	O
at	O
the	O
front	O
and	O
photodetectors	O
at	O
the	O
back	O
.	O
</s>
<s>
This	O
traditional	O
orientation	O
of	O
the	O
sensor	O
places	O
the	O
active	B-General_Concept
matrix	I-General_Concept
of	O
the	O
digital	B-Device
camera	I-Device
image	B-Algorithm
sensor	I-Algorithm
—	O
a	O
matrix	O
of	O
individual	O
picture	O
elements	O
—	O
on	O
its	O
front	O
surface	O
and	O
simplifies	O
manufacturing	O
.	O
</s>
<s>
A	O
back-illuminated	B-Algorithm
sensor	I-Algorithm
contains	O
the	O
same	O
elements	O
,	O
but	O
arranges	O
the	O
wiring	O
behind	O
the	O
photocathode	O
layer	O
by	O
flipping	O
the	O
silicon	O
wafer	O
during	O
manufacturing	O
and	O
then	O
thinning	B-Algorithm
its	O
reverse	O
side	O
so	O
that	O
light	O
can	O
strike	O
the	O
photocathode	O
layer	O
without	O
passing	O
through	O
the	O
wiring	O
layer	O
.	O
</s>
<s>
This	O
change	O
can	O
improve	O
the	O
chance	O
of	O
an	O
input	O
photon	B-Application
being	O
captured	O
from	O
about	O
60%	O
to	O
over	O
90%	O
,	O
(	O
i.e.	O
</s>
<s>
BSI-CMOS	B-Algorithm
sensors	O
are	O
most	O
advantageous	O
in	O
partial	O
sun	O
and	O
other	O
low	O
light	O
conditions	O
.	O
</s>
<s>
Orienting	O
the	O
active	B-General_Concept
matrix	I-General_Concept
transistors	B-Application
behind	O
the	O
photocathode	O
layer	O
can	O
lead	O
to	O
a	O
host	O
of	O
problems	O
,	O
such	O
as	O
crosstalk	O
,	O
which	O
causes	O
image	B-Algorithm
noise	I-Algorithm
,	O
dark	O
current	O
,	O
and	O
color	O
mixing	O
between	O
adjacent	O
pixels	O
.	O
</s>
<s>
Thinning	B-Algorithm
also	O
makes	O
the	O
silicon	O
wafer	O
more	O
fragile	O
.	O
</s>
<s>
Industry	O
observers	O
noted	O
that	O
a	O
back-illuminated	B-Algorithm
sensor	I-Algorithm
could	O
theoretically	O
cost	O
less	O
than	O
a	O
similar	O
front-illuminated	O
version	O
.	O
</s>
<s>
The	O
OV8810	O
was	O
used	O
in	O
the	O
HTC	B-Application
Droid	I-Application
Incredible	I-Application
and	O
HTC	B-Application
EVO	I-Application
4G	I-Application
,	O
which	O
were	O
released	O
in	O
April	O
and	O
June	O
2009	O
,	O
respectively	O
.	O
</s>
<s>
Apple	O
selected	O
the	O
OV5650	O
to	O
use	O
in	O
the	O
back	O
camera	O
of	O
the	O
iPhone	B-Operating_System
4	I-Operating_System
,	O
which	O
garnered	O
good	O
reviews	O
for	O
its	O
low-light	O
photos	O
.	O
</s>
<s>
Sony	O
's	O
work	O
on	O
new	O
photodiode	O
materials	O
and	O
processes	O
allowed	O
them	O
to	O
introduce	O
their	O
first	O
consumer	O
back-illuminated	B-Algorithm
sensor	I-Algorithm
as	O
their	O
CMOS-based	B-Architecture
"	O
Exmor	B-Device
R	I-Device
"	O
in	O
August	O
2009	O
.	O
</s>
<s>
The	O
iPhone	B-Operating_System
4s	I-Operating_System
employed	O
an	O
image	B-Algorithm
sensor	I-Algorithm
manufactured	O
by	O
Sony	O
.	O
</s>
<s>
In	O
2011	O
,	O
Sony	O
implemented	O
their	O
Exmor	B-Device
R	I-Device
sensor	O
in	O
their	O
flagship	O
smartphone	O
Sony	B-Application
Ericsson	I-Application
Xperia	I-Application
Arc	I-Application
.	O
</s>
<s>
In	O
January	O
2012	O
,	O
Sony	O
developed	O
the	O
back-side	O
illuminated	O
sensor	O
further	O
with	O
Stacked	O
CMOS	B-Device
,	O
where	O
the	O
supporting	O
circuitry	O
is	O
moved	O
below	O
the	O
active	O
pixel	O
section	O
,	O
giving	O
another	O
30%	O
improvement	O
to	O
light	O
capturing	O
capability	O
.	O
</s>
<s>
This	O
was	O
commercialized	O
by	O
Sony	O
in	O
August	O
2012	O
as	O
Exmor	B-Device
RS	I-Device
with	O
resolutions	O
of	O
13	O
and	O
8	O
effective	O
megapixels	O
.	O
</s>
<s>
In	O
September	O
2014	O
Samsung	O
announced	O
the	O
world	O
's	O
first	O
APS-C	B-Algorithm
sensor	O
to	O
adopt	O
BSI	O
pixel	O
technology	O
.	O
</s>
<s>
This	O
28	O
MP	O
sensor	O
(	O
S5KVB2	O
)	O
was	O
adopted	O
by	O
their	O
new	O
compact	B-Device
system	I-Device
camera	I-Device
,	O
the	O
NX1	O
,	O
and	O
was	O
showcased	O
along	O
with	O
the	O
camera	O
at	O
Photokina	O
2014	O
.	O
</s>
<s>
In	O
June	O
2015	O
Sony	O
announced	O
the	O
first	O
camera	O
employing	O
a	O
back-side	O
illuminated	O
full	O
frame	O
sensor	O
,	O
the	O
α7R	B-Algorithm
II	I-Algorithm
.	O
</s>
<s>
In	O
August	O
2017	O
Nikon	B-Algorithm
announced	O
that	O
its	O
forthcoming	O
Nikon	B-Algorithm
D850	I-Algorithm
,	O
a	O
full-frame	B-Algorithm
digital	I-Algorithm
SLR	I-Algorithm
camera	O
,	O
would	O
have	O
a	O
back-illuminated	B-Algorithm
sensor	I-Algorithm
on	O
its	O
new	O
45.7	O
MP	O
sensor	O
.	O
</s>
<s>
In	O
September	O
2018	O
Fujifilm	O
announced	O
the	O
availability	O
of	O
the	O
X-T3	B-Algorithm
,	O
a	O
mirrorless	B-Device
interchangeable-lens	I-Device
camera	I-Device
,	O
with	O
a	O
26.1MP	O
APS-C	B-Algorithm
Fujifilm	B-Algorithm
X-Trans	I-Algorithm
sensor	I-Algorithm
back-illuminated	B-Algorithm
sensor	I-Algorithm
.	O
</s>
<s>
In	O
April	O
2021	O
,	O
Canon	O
announced	O
their	O
new	O
R3	O
model	O
would	O
feature	O
a	O
35mm	B-Algorithm
full-frame	I-Algorithm
,	O
back	O
illuminated	O
,	O
stacked	O
CMOS	B-Architecture
sensor	I-Architecture
and	O
a	O
DIGIC	O
X	O
image	O
processor	O
.	O
</s>
<s>
In	O
April	O
2021	O
,	O
Ricoh	O
released	O
the	O
Pentax	B-Algorithm
K-3	I-Algorithm
III	I-Algorithm
featuring	O
a	O
BSI	O
26	O
megapixel	O
APS-C	B-Algorithm
sensor	O
from	O
Sony	O
and	O
a	O
PRIME	O
V	O
image	O
processor	O
.	O
</s>
<s>
In	O
May	O
2021	O
,	O
Sony	O
announced	O
a	O
new	O
back-illuminated	O
,	O
stacked	O
sensor	O
for	O
the	O
Micro	B-Operating_System
Four	I-Operating_System
Thirds	I-Operating_System
format	O
.	O
</s>
