<s>
A	O
seven-segment	B-General_Concept
display	I-General_Concept
is	O
a	O
form	O
of	O
electronic	O
display	B-Device
device	I-Device
for	O
displaying	O
decimal	B-Application
numerals	O
that	O
is	O
an	O
alternative	O
to	O
the	O
more	O
complex	O
dot	B-General_Concept
matrix	I-General_Concept
displays	I-General_Concept
.	O
</s>
<s>
Seven-segment	B-General_Concept
displays	I-General_Concept
are	O
widely	O
used	O
in	O
digital	O
clocks	O
,	O
electronic	O
meters	O
,	O
basic	O
calculators	B-Application
,	O
and	O
other	O
electronic	O
devices	O
that	O
display	O
numerical	O
information	O
.	O
</s>
<s>
In	O
1910	O
,	O
a	O
seven-segment	B-General_Concept
display	I-General_Concept
illuminated	O
by	O
incandescent	O
bulbs	O
was	O
used	O
on	O
a	O
power-plant	O
boiler	O
room	O
signal	O
panel	O
.	O
</s>
<s>
Some	O
early	O
seven-segment	B-General_Concept
displays	I-General_Concept
used	O
incandescent	O
filaments	O
in	O
an	O
evacuated	O
bulb	O
;	O
they	O
are	O
also	O
known	O
as	O
numitrons	O
.	O
</s>
<s>
Minitrons	O
are	O
filament	O
segment	B-Device
displays	I-Device
that	O
are	O
housed	O
in	O
DIP	B-Algorithm
packages	O
like	O
modern	O
LED	O
segment	B-Device
displays	I-Device
.	O
</s>
<s>
They	O
may	O
have	O
up	O
to	O
16	B-General_Concept
segments	I-General_Concept
.	O
</s>
<s>
There	O
were	O
also	O
segment	B-Device
displays	I-Device
that	O
used	O
small	O
incandescent	O
light	O
bulbs	O
instead	O
of	O
LEDs	O
or	O
incandescent	O
filaments	O
.	O
</s>
<s>
These	O
worked	O
similarly	O
to	O
modern	O
LED	O
segment	B-Device
displays	I-Device
.	O
</s>
<s>
Vacuum	B-General_Concept
fluorescent	I-General_Concept
display	I-General_Concept
versions	O
were	O
also	O
used	O
in	O
the	O
1970s	O
.	O
</s>
<s>
Many	O
early	O
(	O
c	B-Language
.	O
1970s	O
)	O
LED	O
seven-segment	B-General_Concept
displays	I-General_Concept
had	O
each	O
digit	O
built	O
on	O
a	O
single	O
die	O
.	O
</s>
<s>
The	O
seven-segment	O
pattern	O
is	O
sometimes	O
used	O
in	O
posters	O
or	O
tags	O
,	O
where	O
the	O
user	O
either	O
applies	O
color	O
to	O
pre-printed	O
segments	O
,	O
or	O
applies	O
color	O
through	O
a	O
seven-segment	O
digit	O
template	B-Algorithm
,	O
to	O
compose	O
figures	O
such	O
as	O
product	O
prices	O
or	O
telephone	O
numbers	O
.	O
</s>
<s>
For	O
many	O
applications	O
,	O
dot-matrix	O
LCDs	B-Device
have	O
largely	O
superseded	O
LED	O
displays	O
in	O
general	O
,	O
though	O
even	O
in	O
LCDs	B-Device
,	O
seven-segment	B-General_Concept
displays	I-General_Concept
are	O
common	O
.	O
</s>
<s>
Unlike	O
LEDs	O
,	O
the	O
shapes	O
of	O
elements	O
in	O
an	O
LCD	B-Device
panel	I-Device
are	O
arbitrary	O
since	O
they	O
are	O
formed	O
on	O
the	O
display	O
by	O
photolithography	B-Algorithm
.	O
</s>
<s>
In	O
contrast	O
,	O
the	O
shapes	O
of	O
LED	O
segments	O
tend	O
to	O
be	O
simple	O
rectangles	O
,	O
reflecting	O
the	O
fact	O
that	O
they	O
have	O
to	O
be	O
physically	O
moulded	O
to	O
shape	O
,	O
which	O
makes	O
it	O
difficult	O
to	O
form	O
more	O
complex	O
shapes	O
than	O
the	O
segments	O
of	O
7-segment	B-General_Concept
displays	I-General_Concept
.	O
</s>
<s>
However	O
,	O
the	O
high	O
recognition	O
factor	O
of	O
seven-segment	B-General_Concept
displays	I-General_Concept
,	O
and	O
the	O
comparatively	O
high	O
visual	O
contrast	O
obtained	O
by	O
such	O
displays	O
relative	O
to	O
dot-matrix	O
digits	O
,	O
makes	O
seven-segment	O
multiple-digit	O
LCD	B-Device
screens	I-Device
very	O
common	O
on	O
basic	O
calculators	B-Application
.	O
</s>
<s>
The	O
seven-segment	B-General_Concept
display	I-General_Concept
has	O
inspired	O
type	O
designers	O
to	O
produce	O
typefaces	O
reminiscent	O
of	O
that	O
display	O
(	O
but	O
more	O
legible	O
)	O
,	O
such	O
as	O
New	O
Alphabet	O
,	O
"	O
DB	O
LCD	B-Device
Temp	O
"	O
,	O
"	O
ION	O
B	O
"	O
,	O
etc	O
.	O
</s>
<s>
Using	O
a	O
restricted	O
range	O
of	O
letters	O
that	O
look	O
like	O
(	O
upside-down	O
)	O
digits	O
,	O
seven-segment	B-General_Concept
displays	I-General_Concept
are	O
commonly	O
used	O
by	O
school	O
children	O
to	O
form	O
words	O
and	O
phrases	O
using	O
a	O
technique	O
known	O
as	O
"	O
calculator	B-Application
spelling	O
"	O
.	O
</s>
<s>
Seven-segment	B-General_Concept
displays	I-General_Concept
may	O
use	O
a	O
liquid	B-Device
crystal	I-Device
display	I-Device
(	O
LCD	B-Device
)	O
,	O
a	O
light-emitting	O
diode	O
(	O
LED	O
)	O
for	O
each	O
segment	O
,	O
an	O
electrochromic	O
display	O
,	O
or	O
other	O
light-generating	O
or	O
controlling	O
techniques	O
such	O
as	O
cold	O
cathode	O
gas	O
discharge	O
(	O
Panaplex	O
)	O
,	O
vacuum	B-General_Concept
fluorescent	I-General_Concept
(	O
VFD	O
)	O
,	O
incandescent	O
filaments	O
(	O
Numitron	O
)	O
,	O
and	O
others	O
.	O
</s>
<s>
For	O
gasoline	O
price	O
totems	O
and	O
other	O
large	O
signs	O
,	O
vane	B-General_Concept
displays	I-General_Concept
made	O
up	O
of	O
electromagnetically	O
flipped	O
light-reflecting	O
segments	O
(	O
or	O
"	O
vanes	O
"	O
)	O
are	O
still	O
commonly	O
used	O
.	O
</s>
<s>
A	O
precursor	O
to	O
the	O
7-segment	B-General_Concept
display	I-General_Concept
in	O
the	O
1950s	O
through	O
the	O
1970s	O
was	O
the	O
cold-cathode	O
,	O
neon-lamp-like	O
nixie	B-Application
tube	I-Application
.	O
</s>
<s>
Starting	O
in	O
1970	O
,	O
RCA	O
sold	O
a	O
display	B-Device
device	I-Device
known	O
as	O
the	O
that	O
used	O
incandescent	O
filaments	O
arranged	O
into	O
a	O
seven-segment	B-General_Concept
display	I-General_Concept
.	O
</s>
<s>
In	O
USSR	O
,	O
the	O
first	O
electronic	O
calculator	B-Application
"	O
Vega	O
"	O
,	O
which	O
was	O
produced	O
from	O
1964	O
,	O
contains	O
20	O
decimal	B-Application
digits	O
with	O
seven-segment	O
electroluminescent	O
display	O
.	O
</s>
<s>
Hence	O
a	O
7	B-General_Concept
segment	I-General_Concept
plus	O
decimal	B-Application
point	O
package	O
will	O
only	O
require	O
nine	O
pins	O
,	O
though	O
commercial	O
products	O
typically	O
contain	O
more	O
pins	O
,	O
and/or	O
spaces	O
where	O
pins	O
would	O
go	O
,	O
in	O
order	O
to	O
match	O
standard	O
IC	O
sockets	O
.	O
</s>
<s>
Multiple-digit	O
LED	O
displays	O
as	O
used	O
in	O
pocket	O
calculators	B-Application
and	O
similar	O
devices	O
used	O
multiplexed	B-General_Concept
displays	I-General_Concept
to	O
reduce	O
the	O
number	O
of	O
I/O	O
pins	O
required	O
to	O
control	O
the	O
display	O
.	O
</s>
<s>
In	O
this	O
manner	O
an	O
eight	O
digit	O
display	O
with	O
seven	O
segments	O
and	O
a	O
decimal	B-Application
point	O
would	O
require	O
only	O
8	O
cathode	O
drivers	O
and	O
8	O
anode	O
drivers	O
,	O
instead	O
of	O
sixty-four	O
drivers	O
and	O
IC	O
pins	O
.	O
</s>
<s>
Often	O
in	O
pocket	O
calculators	B-Application
the	O
digit	O
drive	O
lines	O
would	O
be	O
used	O
to	O
scan	O
the	O
keyboard	O
as	O
well	O
,	O
providing	O
further	O
savings	O
;	O
however	O
,	O
pressing	O
multiple	O
keys	O
at	O
once	O
would	O
produce	O
odd	O
results	O
on	O
the	O
multiplexed	B-General_Concept
display	I-General_Concept
.	O
</s>
<s>
Although	O
to	O
a	O
naked	O
eye	O
all	O
digits	O
of	O
an	O
LED	O
display	O
appear	O
lit	O
,	O
only	O
one	O
digit	O
is	O
lit	O
at	O
any	O
given	O
time	O
in	O
a	O
multiplexed	B-General_Concept
display	I-General_Concept
.	O
</s>
<s>
In	O
most	O
applications	O
,	O
the	O
segments	O
are	O
of	O
nearly	O
uniform	O
shape	O
and	O
size	O
(	O
usually	O
elongated	O
hexagons	B-Application
,	O
though	O
trapezoids	O
and	O
rectangles	O
can	O
also	O
be	O
used	O
)	O
,	O
though	O
in	O
the	O
case	O
of	O
adding	O
machines	O
,	O
the	O
vertical	O
segments	O
are	O
longer	O
and	O
more	O
oddly	O
shaped	O
at	O
the	O
ends	O
in	O
an	O
effort	O
to	O
further	O
enhance	O
readability	O
.	O
</s>
<s>
The	O
segments	O
are	O
referred	O
to	O
by	O
the	O
letters	O
A	O
to	O
G	O
,	O
where	O
the	O
optional	O
decimal	B-Application
point	O
(	O
an	O
"	O
eighth	O
segment	O
"	O
,	O
referred	O
to	O
as	O
DP	O
)	O
is	O
used	O
for	O
the	O
display	O
of	O
non-integer	O
numbers	O
.	O
</s>
<s>
A	O
single	O
byte	O
can	O
encode	O
the	O
full	O
state	O
of	O
a	O
7-segment-display	O
including	O
the	O
decimal	B-Application
point	O
.	O
</s>
<s>
In	O
the	O
gfedcba	O
representation	O
,	O
a	O
byte	O
value	O
of	O
0x06	O
would	O
turn	O
on	O
segments	O
"	O
c	B-Language
"	O
and	O
"	O
b	O
"	O
,	O
which	O
would	O
display	O
a	O
"	O
1	O
"	O
.	O
</s>
<s>
The	O
numerical	O
digits	O
0	O
to	O
9	B-General_Concept
are	O
the	O
most	O
common	O
characters	O
displayed	O
on	O
seven-segment	B-General_Concept
displays	I-General_Concept
.	O
</s>
<s>
Alternate	O
patterns	O
:	O
The	O
numeral	O
1	O
may	O
be	O
represented	O
with	O
the	O
left	O
segments	O
,	O
the	O
numerals	O
6	O
and	O
9	B-General_Concept
may	O
be	O
represented	O
without	O
a	O
"	O
tail	O
"	O
,	O
and	O
the	O
numeral	O
7	O
represented	O
with	O
a	O
'	O
tail	O
 '	O
:	O
</s>
<s>
In	O
Unicode	O
13.0	O
,	O
10	O
codepoints	O
had	O
been	O
given	O
for	O
segmented	O
digits	O
0	O
–	O
9	B-General_Concept
in	O
the	O
Symbols	O
for	O
Legacy	O
Computing	O
block	O
,	O
to	O
replicate	O
early	O
computer	O
fonts	O
that	O
included	O
seven-segment	O
versions	O
of	O
the	O
digits	O
.	O
</s>
<s>
Four	O
binary	O
bits	O
are	O
needed	O
to	O
specify	O
the	O
numbers	O
0	O
–	O
9	B-General_Concept
,	O
but	O
can	O
also	O
specify	O
10	O
–	O
15	O
,	O
so	O
usually	O
decoders	O
with	O
4	O
bit	O
inputs	O
can	O
also	O
display	O
Hexadecimal	O
(	O
Hex	O
)	O
digits	O
.	O
</s>
<s>
By	O
choosing	O
better	O
synonyms	B-Application
,	O
it	O
is	O
possible	O
to	O
work	O
around	O
many	O
shortcomings	O
of	O
seven-segment	O
alphabet	O
encodings	O
.	O
</s>
<s>
Lowercase	O
letters	O
"	O
b	O
"	O
and	O
"	O
q	O
"	O
are	O
identical	O
to	O
the	O
alternate	O
numerical	O
digits	O
'	O
6	O
 '	O
and	O
'	O
9	B-General_Concept
 '	O
.	O
</s>
<s>
on	O
a	O
CD	O
player	O
)	O
are	O
also	O
commonly	O
represented	O
on	O
7-segment	B-General_Concept
displays	I-General_Concept
.	O
</s>
<s>
Seven-segment	B-General_Concept
displays	I-General_Concept
have	O
also	O
been	O
used	O
to	O
show	O
letters	O
of	O
the	O
Cyrillic	O
and	O
Greek	O
alphabets	O
:	O
</s>
<s>
When	O
all	O
letters	O
need	O
to	O
be	O
displayed	O
on	O
a	O
device	O
,	O
sixteen-segment	B-General_Concept
and	O
dot	B-General_Concept
matrix	I-General_Concept
displays	I-General_Concept
are	O
better	O
choices	O
than	O
seven-segment	B-General_Concept
displays	I-General_Concept
.	O
</s>
<s>
+	O
Punctuation	O
encodings	O
Glyph	O
Display	O
Unicode	O
Name(s )	O
0x0020	O
Space	O
,	O
Blank	O
,	O
All	O
segments	O
off	O
_	O
0x005F	O
Underscore	O
,	O
Low	O
dash	B-Protocol
,	O
Low	O
line	O
-	O
0x002D	O
Hyphen-minus	O
,	O
Minus	O
,	O
Negative	O
,	O
Hyphen	O
,	O
Dash	B-Protocol
‾	O
0x203E	O
Overline	O
,	O
Overscore	O
,	O
Overbar	O
,	O
Macron	O
=	O
0x003D	O
Equals	O
,	O
Double	O
hyphen	O
=	O
0x207C	O
Superscript	O
"	O
equals	O
"	O
≡	O
0x2261	O
Triple	O
bar	O
,	O
Hamburger	O
button	O
,	O
Identical	O
To	O
°	O
0x00B0	O
Degree	O
,	O
Superscript	O
zero	O
"	O
0x0022	O
Double	O
quote	O
,	O
Double	O
prime	O
'	O
0x0027	O
Apostrophe	B-Language
,	O
Single	O
quote	O
,	O
Prime	O
(	O
or	O
[	O
0x005B	O
Parenthesis	O
,	O
Bracket	O
(	O
conflicts	O
with	O
uppercase	O
C	B-Language
)	O
)	O
or	O
]	O
0x005D	O
Parenthesis	O
,	O
Bracket	O
?	O
</s>
<s>
In	O
the	O
past	O
,	O
some	O
seven-segment	O
decoder	O
ICs	O
did	O
n't	O
output	O
the	O
following	O
modern	O
decimal/hexadecimal	O
font	O
.	O
</s>
<s>
For	O
"	O
1	O
"	O
,	O
the	O
MC14558B	O
displays	O
the	O
number	O
on	O
the	O
left	O
side	O
of	O
the	O
display	O
using	O
segments	O
"	O
e	O
"	O
and	O
"	O
f	O
"	O
instead	O
of	O
the	O
usual	O
"	O
b	O
"	O
and	O
"	O
c	B-Language
"	O
.	O
</s>
<s>
For	O
"	O
6	O
"	O
and	O
"	O
9	B-General_Concept
"	O
,	O
the	O
CD4511B	O
,	O
MC14558B	O
,	O
TC5002	O
,	O
SN74x46/SN74x47/SN74x48/SN74x49	O
displays	O
both	O
numbers	O
without	O
a	O
"	O
tail	O
"	O
,	O
where	O
"	O
x	O
"	O
is	O
the	O
TTL	O
logic	O
family	O
.	O
</s>
<s>
The	O
MM74C912	O
displayed	O
"	O
o	O
"	O
for	O
A	O
and	O
B	O
,	O
"	O
−	O
"	O
for	O
C	B-Language
,	O
D	O
and	O
E	O
,	O
and	O
blank	O
for	O
F	O
.	O
The	O
CD4511B	O
just	O
displayed	O
blanks	O
.	O
</s>
<s>
Soviet	O
programmable	B-Application
calculators	I-Application
like	O
the	O
Б3	O
–	O
34	O
used	O
the	O
symbols	O
"	O
−	O
"	O
,	O
"	O
L	O
"	O
,	O
"	O
C	B-Language
"	O
,	O
"	O
Г	O
"	O
,	O
"	O
E	O
"	O
,	O
and	O
"	O
"	O
(	O
space	O
)	O
,	O
allowing	O
the	O
error	O
message	O
EГГ0Г	O
to	O
be	O
displayed	O
.	O
</s>
