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Cautions for Handling the Laser Pick-up
The
laser
pick-up
KSS-151A
is assembled
and
precisely
adjusted using a sophisticated manufacturing process in our
plant.
Do not disassemble or attempt to readjust it. Please
keep the following instructions carefully in handling pick-
up.
1. General Care
(1) Storage
Do not store the pick-up in dusty, high-temperatured
or high-humidity environments.
(2)
Please take care for preventing from shock by falling
down or careless handling.
2. Laser Diode (LD)
(1) Protect your eyes
The laser beam may damage the human eye, since the
intensity of the focused spot may reach 1.3 x 10* W/
cm? even if the intensity at the object lens is 400 UW
maximum,
As the light beam
spreads after focused
through the objective lens, it does not effect you in the
place as far as more than 30cms.
However, do not
look
at
the
laser
light
beam
either
through
the
objective lens directly nor another lens or a mirror,
(2) Poison of As
Since the LD chip contains As (Arsenic), as GaAs +
GaAlAs, as known as the poison, although the poison
is relatively
weak,
in comparing.
with
others,
e.g.
As,03,
AsCl3 etc., and the amount
is small, avoid
putting the chip in acid or an alkali solution, heating it
over 200°C or putting it into your mouth... ..
(3) Avoid surge current or electrostatic discharge
The LD may
be damaged
or deteriorated by it's own
strong light if a large current is supplied to it, even if
only a short pulse. —
-Make
sure that there
is no
surge current
in the LD
driving circuit by switches or else. Be careful to handle
pick-up as it may be damaged in a moment by human
electrostaic discharge.
The pins of the LD are short-
circuited
by solder
for protection
during
shipment
(Soldered short circuit portion (A)].
For safety handling of an LD, grounding the human
body, measuring equipments and jig is strongly recom-
mended,
And still it is further desirable to make use of
mat on the platform and floor for handling the LD.
To open the short circuit, remove the soldering quickly
with
a soldering
iron whose metal part is grounded.
The temperature
of the soldering iron should
be less
than 320°C (30W).
'\
3, X-axis Actuator
(1) The
performance
of the actuator may
be effected
if
magnetic material is located nearby, since the actuator
has a strong magnetic circuit.
Do not permit dust to
enter through the clearance of the cover.
(2) Cleaning the lens
It may change the specifications when
dust or dirt is
stuck on the object lens.
For cleaning, use a dry_tense¥@aning paper applying
no excessive pressure to the lens. If it is difficult to re-
move
it, moisten
the paper
with a little amount
of
water. At this time never drip water other than the lens
portion.
4. The Metal Bearing
The
metal
bearing of Cu-compound
sintered alloy is im-
pregnated with oil. However, supply oi! with the specified
oil Froil 0147P, at the pick-up replacing time. You do not
normally need lublicate the bushing in initializing time nor
supplying oil in running time.
5. Handling
Please
handle
the laser pick-up
with
holding
by optical
base.
When
either a part of human
body or some
other things
may happen to touch directly with the circuit part of either
the LD or PD PCB, it may cause deterioration, take careful
attention in handling this base.
6. Deterioration of Laser Pick-up
When
difficulty occurs either in focus or tracking adjust-
ment nor able to adjust the focus or tracking, it seems that
the laser pick-up is deteriorated.
In these cases, check a
value
of
laser
diode
current
and
give
a decision
for
deterioration.
7. Fundamental Deterioration Decision of Laser Pick-up
(1) If a voltage value across Pin @) of TP102 (+5V) and
Pin @ (iop) of Unit (2U-1454) is V1, the value of laser
diode current "'iop 1'' can be found a formula
iop it
(2)
If a "iop" exceeds +10% compared with the IOP indi-
cation on the laser pick-up mameplate, there is a fair
chance
for deterioration
when
it is checked
under a
circumambient temperature 23°C.
(3) When
the circumambient temperature changes +10°C,
"iop
1" will change
5%.
The "'iop 1°' will also be
changed the passage of time.
(4)
In case of the above conditions taking into considera-
tion and performed
the adjustment in proper way, if
the HF level across pin (1) and across (HF) GND of
TP102 in 2U-1454 becomes 0.6V or less values; or a _
gitter
occurs
great,
the
laser
pick-up
is may
be
deteriorated.
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