<s>
A	O
screen	B-General_Concept
protector	I-General_Concept
is	O
an	O
additional	O
sheet	O
of	O
material	O
—	O
commonly	O
polyurethane	O
or	O
laminated	O
glass	O
—	O
that	O
can	O
be	O
attached	O
to	O
the	O
screen	O
of	O
an	O
electronic	O
device	O
and	O
protect	O
it	O
against	O
physical	O
damage	O
.	O
</s>
<s>
The	O
first	O
screen	B-General_Concept
protector	I-General_Concept
was	O
designed	O
and	O
patented	O
by	O
Herbert	O
Schlegel	O
in	O
1968	O
for	O
use	O
on	O
television	O
screens	O
.	O
</s>
<s>
Screen	B-General_Concept
protectors	I-General_Concept
first	O
entered	O
the	O
mobile-device	B-Application
market	O
after	O
the	O
rise	O
of	O
personal	B-Application
digital	I-Application
assistants	I-Application
(	O
PDAs	B-Application
)	O
.	O
</s>
<s>
Since	O
PDAs	B-Application
were	O
often	O
operated	O
via	O
a	O
stylus	B-Device
,	O
the	O
tip	O
of	O
the	O
stylus	B-Device
could	O
scratch	O
the	O
sensitive	O
LCD	B-Device
screen	I-Device
surface	O
.	O
</s>
<s>
Therefore	O
,	O
screen	B-General_Concept
protectors	I-General_Concept
provided	O
sacrificial	O
protection	O
from	O
this	O
damage	O
.	O
</s>
<s>
Since	O
then	O
,	O
the	O
ubiquity	O
of	O
mobile-devices	O
have	O
seen	O
the	O
screen	B-General_Concept
protector	I-General_Concept
become	O
more	O
widely	O
used	O
.	O
</s>
<s>
Screen	B-General_Concept
protectors	I-General_Concept
are	O
made	O
of	O
either	O
plastics	O
,	O
such	O
as	O
polyethylene	O
terephthalate	O
(	O
PET	O
)	O
or	O
thermoplastic	O
polyurethane	O
(	O
TPU	O
)	O
,	O
or	O
of	O
laminated	O
tempered	O
glass	O
,	O
similar	O
to	O
the	O
device	O
’s	O
original	O
screen	O
they	O
are	O
meant	O
to	O
protect	O
.	O
</s>
<s>
Plastic	O
screen	B-General_Concept
protectors	I-General_Concept
cost	O
less	O
than	O
glass	O
and	O
are	O
thinner	O
(	O
around	O
thick	O
,	O
compared	O
to	O
for	O
glass	O
)	O
and	O
more	O
flexible	O
.	O
</s>
<s>
Screen	B-General_Concept
protectors	I-General_Concept
 '	O
surface	O
can	O
be	O
glossy	O
or	O
matte	O
.	O
</s>
<s>
Screen	B-General_Concept
protectors	I-General_Concept
have	O
been	O
known	O
to	O
interfere	O
with	O
the	O
operation	O
of	O
some	O
touchscreens	B-Device
.	O
</s>
<s>
Also	O
,	O
an	O
existing	O
oleophobic	O
coating	O
of	O
a	O
touchscreen	B-Device
will	O
be	O
covered	O
,	O
although	O
some	O
tempered	O
glass	O
screen	B-General_Concept
protectors	I-General_Concept
come	O
with	O
their	O
own	O
oleophobic	O
coating	O
.	O
</s>
<s>
On	O
some	O
devices	O
,	O
the	O
thickness	O
of	O
screen	B-General_Concept
protectors	I-General_Concept
can	O
affect	O
the	O
look	O
and	O
feel	O
of	O
the	O
device	O
.	O
</s>
<s>
The	O
main	O
function	O
of	O
this	O
screen	B-General_Concept
protector	I-General_Concept
is	O
to	O
protect	O
the	O
LCD	B-Device
screen	I-Device
from	O
all	O
kinds	O
of	O
threats	O
that	O
can	O
reduce	O
user	O
discomfort	O
,	O
such	O
as	O
:	O
</s>
<s>
Scratches	O
:	O
scratches	O
caused	O
by	O
blunt	O
objects	O
,	O
with	O
a	O
protective	O
film	O
the	O
LCD	B-Device
screen	I-Device
is	O
protected	O
against	O
any	O
scratches	O
that	O
could	O
damage	O
the	O
screen	O
surface	O
.	O
</s>
<s>
Sunlight	O
:	O
Exposure	O
to	O
sunlight	O
can	O
reduce	O
the	O
image	O
quality	O
of	O
the	O
LCD	B-Device
screen	I-Device
.	O
</s>
<s>
With	O
a	O
screen	B-General_Concept
protector	I-General_Concept
,	O
everyone	O
can	O
see	O
the	O
LCD	B-Device
screen	I-Device
clearly	O
and	O
not	O
be	O
disturbed	O
by	O
the	O
reflection	O
of	O
sunlight	O
.	O
</s>
<s>
Dust	O
:	O
Dirt	O
adhering	O
to	O
the	O
LCD	B-Device
screen	I-Device
is	O
very	O
difficult	O
to	O
clean	O
because	O
the	O
LCD	B-Device
screen	I-Device
is	O
a	O
high	O
sensitivity	O
screen	O
,	O
with	O
a	O
protective	O
film	O
;	O
it	O
is	O
easy	O
to	O
clean	O
the	O
LCD	B-Device
screen	I-Device
.	O
</s>
<s>
If	O
you	O
are	O
afraid	O
to	O
do	O
cleaning	O
,	O
simply	O
remove	O
the	O
dusty	O
screen	B-General_Concept
protector	I-General_Concept
and	O
replace	O
it	O
with	O
a	O
new	O
one	O
.	O
</s>
<s>
Water	O
:	O
water	O
on	O
the	O
LCD	B-Device
screen	I-Device
can	O
be	O
fatal	O
to	O
the	O
surface	O
of	O
the	O
screen	O
.	O
</s>
<s>
With	O
the	O
protection	O
provided	O
by	O
the	O
screen	B-General_Concept
protector	I-General_Concept
,	O
water	O
will	O
not	O
easily	O
penetrate	O
and	O
damage	O
components	O
inside	O
the	O
LCD	B-Device
screen	I-Device
.	O
</s>
