<s>
The	O
skiatron	B-Algorithm
is	O
a	O
type	O
of	O
cathode	O
ray	O
tube	O
(	O
CRT	O
)	O
that	O
replaces	O
the	O
conventional	O
phosphor	O
with	O
some	O
type	O
of	O
scotophor	O
,	O
typically	O
potassium	O
chloride	O
.	O
</s>
<s>
Skiatrons	B-Algorithm
were	O
used	O
as	O
an	O
early	O
form	O
of	O
projection	O
television	O
display	O
,	O
particularly	O
in	O
radar	B-Application
stations	I-Application
during	O
World	O
War	O
II	O
.	O
</s>
<s>
During	O
World	O
War	O
II	O
,	O
radar	B-Application
displays	O
using	O
potassium	O
chloride	O
evaporated	O
on	O
a	O
mica	O
plate	O
as	O
target	O
material	O
were	O
actively	O
developed	O
in	O
England	O
,	O
Germany	O
,	O
the	O
United	O
States	O
,	O
and	O
the	O
Soviet	O
Union	O
.	O
</s>
<s>
Skiatrons	B-Algorithm
were	O
used	O
as	O
an	O
early	O
form	O
of	O
projection	O
television	O
display	O
,	O
particularly	O
in	O
radar	B-Application
stations	I-Application
during	O
World	O
War	O
II	O
.	O
</s>
<s>
The	O
skiatron	B-Algorithm
was	O
mounted	O
below	O
a	O
translucent	O
plotting	O
table	O
surface	O
and	O
brightly	O
lit	O
with	O
mercury	O
arc	O
stage	O
lights	O
.	O
</s>
<s>
The	O
image	O
on	O
the	O
surface	O
reflected	O
onto	O
the	O
bottom	O
of	O
the	O
plotting	O
table	O
,	O
using	O
a	O
spherical	O
mirror	O
and	O
a	O
Schmidt	O
corrector	O
plate	O
,	O
in	O
the	O
same	O
fashion	O
as	O
an	O
opaque	B-General_Concept
projector	I-General_Concept
,	O
producing	O
an	O
image	O
of	O
the	O
radar	B-Application
display	O
at	O
a	O
much	O
larger	O
size	O
.	O
</s>
<s>
A	O
variety	O
of	O
methods	O
were	O
used	O
to	O
erase	O
the	O
skiatrons	B-Algorithm
.	O
</s>
<s>
UK	O
radars	B-Application
used	O
fans	O
to	O
cool	O
the	O
tubes	O
which	O
were	O
being	O
heated	O
by	O
the	O
stage	O
lighting	O
of	O
the	O
projectors	O
.	O
</s>
<s>
German	O
examples	O
used	O
a	O
thin	O
,	O
transparent	O
layer	O
of	O
tungsten	B-Application
deposited	O
on	O
the	O
front	O
of	O
the	O
tube	O
,	O
which	O
heated	O
up	O
when	O
current	O
was	O
passed	O
through	O
it	O
.	O
</s>
<s>
After	O
the	O
war	O
,	O
skiatrons	B-Algorithm
were	O
also	O
used	O
for	O
storage	O
oscilloscopes	O
,	O
which	O
were	O
viewed	O
directly	O
instead	O
of	O
as	O
a	O
projection	O
system	O
.	O
</s>
<s>
Some	O
examples	O
included	O
separate	O
areas	O
on	O
the	O
screen	O
covered	O
with	O
potassium	O
chloride	O
or	O
phosphor	O
,	O
allowing	O
the	O
display	O
to	O
be	O
set	O
up	O
on	O
the	O
phosphor	O
section	O
and	O
then	O
recorded	O
on	O
the	O
skiatron	B-Algorithm
section	O
.	O
</s>
<s>
There	O
was	O
some	O
interest	O
in	O
the	O
post-war	O
era	O
using	O
skiatrons	B-Algorithm
for	O
large-format	O
projection	O
televisions	O
,	O
but	O
no	O
known	O
commercial	O
use	O
can	O
be	O
found	O
.	O
</s>
<s>
Even	O
the	O
use	O
in	O
radar	B-Application
was	O
not	O
widespread	O
;	O
looking	O
for	O
an	O
even	O
larger	O
format	O
system	O
with	O
better	O
properties	O
,	O
the	O
RAF	O
turned	O
to	O
the	O
Photographic	O
Display	O
Unit	O
,	O
a	O
system	O
that	O
took	O
a	O
photograph	O
of	O
the	O
display	O
,	O
rapidly	O
processed	O
it	O
,	O
and	O
then	O
projected	O
it	O
through	O
a	O
modified	O
movie	B-Application
projector	I-Application
.	O
</s>
<s>
Even	O
with	O
this	O
complexity	O
,	O
it	O
was	O
faster	O
than	O
the	O
skiatrons	B-Algorithm
,	O
producing	O
a	O
new	O
image	O
every	O
15	O
seconds	O
while	O
the	O
skiatron	B-Algorithm
units	O
were	O
typically	O
longer	O
due	O
to	O
the	O
erasure	O
process	O
.	O
</s>
