Filter
Top Products
Example
2:
CE330S (light
passing
through
the
notch
is
sensed
and
decoded
as
write
protect)
(Double
side,
Double density)
Write
enabled
Front
side
O
0
Light
is
interrupted
by the
label
Write
protected
Front
side
o
0
-r-
nhibit notch
Two
types
of
write
protection
are
used
and
attention
must bepaid
to the
presience
of the
label
because
it may
cause
a
wrong result
if the
label
is
used
improperly.
5)
Media recording methods
Two
recording methode
are
used:
• FM
method
(Single density)
This
method
is
called
the
freqency modulation (FM)
1
0 0
n n n n
C D C D C D C
or
double
frequency
(DF).
Clock
and
data
are
written
on
the
media
which
requires
that
a
clock
bit
that
precede
the
data.
I
fL_JL_fl
0
JL
(C:
clock,
D:
data)
Waveforms
of
data
written
or
read
in the FM
mode
are
shown
below.
r*-
Write
data
(WD)
Write
current
Residual magnetic
flux
on the
media
y
Differentiate
^
waveform
Shaped
waveform
Read
data
(RD)
T_J
—
•«—
\
_
fi_i
.—
>
9
US
4
D
ILJ
1
L_J
—
*•
/
J
r\
i
—
i
i_
k
C
I) C D C
n
n n
0
^v
n
0
»•
^s
r/
n
l
—
i
.«—
~\
\
vy
i i
fl_J
D
ILJ
1
1
—
»•
J
r\
rn
n_j
C
D C D
i n i
0
+
"^
X
n
0
•\
y
f-'
L
J
>
Wrote
Read
Write
current:
The
write
data
is
input
to the
flipflop
and
is
inverted
each
time
a
pulse
is
received
to
change
the
direction
of
writing current.
Read
waveform:
The
peak
of the
waveform
is
detected
at
a
change
of
magnetic
flux.
The
waveform
is
than
shaped
to
obtain
read
data identic
it
>.<_•
tlirf
write
data.
Data
cycle
will
be
4/^s.