1050MD/DM-5090(K) COVER 97.11.28 2:25 AM y[W 22
1050MD/DM-5090/DM-9090
CIRCUIT DESCRIPTION
4-7 Precaution on use of test mode5) Take care that VC and GND (ground) are not connected
< An erasure prevention control is not detected in the teston the oscilloscope when two or more signals are moni-
mode. Therefore, when the recording laser power modetored on the oscilloscope. (VC and GND are short-cir-
such as continuous recording mode and traverse adjust-cuited in this case.)
ment mode is entered, the contents of the existing record-Note : The "#" display on the screen indicates an arbitrary
ing are erased irrespective of the control position. Be care-figure.
ful not to enter the continuous recording mode and traverse
adjustment mode when using a disc, containing the data5-4 Creating the recordable continuous recording
that should not be erased, in the test mode.disc
This disc is used for focus bias adjustment and error rate
confirmation. How to create the recordable continuous
5. Electrical adjustmentrecording disc is described below.
5-1 Precaution during confirmation of Laser Diode
1. Insert a commercial recordable disc (blank disc).
emission
During adjustment, do not view the emission of a laser diode2. Turn the JOG DIAL to display OCREC MODE.�
3. Press the ENTER key to display OCREC IN�.
from just above for confirmation. This may damage your eyes.
4. Turn the JOG DIAL (CW ) to display OCREC-MID�.
5. After pressed the ENTER key, a display indicates
5-2 Precaution on handling of Optical pick-up (KMS-
260A)OCREC(0300)� and the recording begins.
The laser diode in an optical pick-up is easy to be subject to6. Terminate the recording within five minutes.
electrostatic destruction. Therefore, solder-bridge the laser tap7. Press the DELETE key to stop the recording.
on the flexible board when handling the optical pick-up.8. Press the EJECT key to take out the recordable disc.
When removing the flexible board from the connector, make aAs a result, a continuously recorded disc can be created for
solder bridge in advance, then remove the board. Be careful
focus bias adjustment and error rate confirmation.
not to remove the solder bridge before inserting the connector.
Note :Take care that no vibration is applied during continu-
Moreover, take careful measures against electrostatic destruc-
ous recording.
tion. The flexible board is cut easily. Handle the flexible board
with care.Pick-up
Flexible board5-5 Laser power adjustment
Connection :
Laser
power m eter
Laser tap
5-3 Precaution during adjustment
Objective lens of
1) Perform the adjustment and confirmation marked with OO�
optical pick up
in the order shown in the table when the parts below are
replaced.Digital
2) In the test mode, perform the adjustment. After adjustmentvoltm eter
is completed, cancel the test mode.
X33
OpticalBD boardADJUSTM ENT
pick-up IC6 D101IC1,IC2,IC10TP2+
1.Temperature compen-TP1-
sation offset adjustmentXOOO
2.Laser power adjustment OOXOAdjustment :
3.Traverse adjustmentOOXO1. Put the laser power meter on the objective lens of the
optical pick-up. Connect the digital voltmeter to TP1 and4.Focus bias adjustment OOXO
5.Error rate confirmationOOXO
TP2.
3) Perform the adjustment in the order described.2. Turn the JOG DIAL to display OLDPWR ADJUST�.
4) Use the following tools and measurement equipment.(Laser power : For adjustment use)
Y CD test disc TGYS-1
3. Press the ENTER key to display O(0.9mW)$##�.
Y Laser power meter
4. Adjust to turn JOG DIAL so that the laser power meter
Y Oscilloscope (with bandwidth of more than 40 M1 )
(Calibrate the probe before measurement.)reads 0.86 - 0.94mW.
Set range 10mW of the laser power meter,then save to
Y Digital voltmeter
press ENTER key.
Y Thermometer
5. O(7.0mW)$##� is displayed.
6. Adjust to turn the JOG DIAL so that laser power meter
reads 6.9-7.1mW, then save to press ENTER key.
("LDPWR<$##" is displayed monentarily.)
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ACEC
