Optical Drive System - Sony CBK-HD01 Maintenance Manual

1-2-8. Optical Drive System

Recording System
Recording data sent from the DVP-45 board through the
ATA bus (Ultra ATA33) is sent to the Blu-ray Disc
Controller (BDC) IC300 on the DR-606 board.
The BDC performs signal processing to conform to
recording format, such as ATA interface, ECC coding and
17PP (Parity Preserve/Prohibit RMTR) modulation.
The recording data is converted to multi-pulse in the BDC,
and the multi-pulse data is sent through the flexible card
wire to the optical block to be written into the disc.
Playback System
• Data Playback System
The RF signal played back from the disc is sent from the
optical block to the Front End Processor (FEP) IC200 on
the DR-606 board where equalizing and asymmetry
correction are performed after the RF signal passes
through the AGC. After A/D conversion by the read
clock played back in the PLL, the signal is sent to the
BDC IC300.
In the BDC, the signal passes through the adaptive
digital filter, and Viterbi demodulation, 17PP demodula-
tion, and ECC decoding are applied to the signal. Then
the signal is sent through the ATA bus to the DVP-45
board as played back data.
• Address restoration system
The address data restored from the disc is sent from the
optical block to the FEP (IC200) on the DR-606 board.
The analog address data passes through the AGC and
BPF and is converted to digital data in the FEP. The
digital data is then sent to the BDC (IC300) for address
decoding.
The PLL in the FEP generates a wobble clock (WCK).
Servo System
• Tri-Axis Actuator and SA Actuator
The object lens of the optical block is controlled for
focus direction, track direction, and tilt angle by the tri
axis actuator.
The light reflected from the disc is converted to the
electrical signal by the optical block. The electrical
signal is input to the FEP IC200, and the focus error
signal and the track error signal are detected. The SV
DSP IC400 outputs the control data based on the errors
to the driver IC501 and controls the focus actuator and
the track actuator through the driver.
1-16
The tilt actuator is controlled for its angle against the
disc to be optimum based on the tilt adjustment result for
the jitter of the playback signal to be minimum and the
output of the angular velocity sensor.
The SA actuator position is controlled for the spherical
aberration to be optimum at the start-up adjustment when
the disc is inserted. The SA actuator for the double layer
disc is controlled to the optimum position every time to
jump the layer.
• Seek Motor
The seek motor controls the position of the optical block
so that the track to be recorded or played back is kept
within the object lens driving range.
• ND Filter
The transmission factor of the ND filter is selectable to
reduce the laser noise that occurs when the read power
light is emitted for the single layer disc.
• Spindle Motor
The FG generated by the spindle motor is amplified and
shaped on the SE-857 board, and is then input into the
SV DSP IC400 on the DR-606 board.
The SV DSP compares the FG frequency with the target
frequency, and then controls the spindle motor via the
driver IC500.
System Control
The SY CPU IC600 on the DR-606 board performs system
control. It controls ATA interface, Data Manager, RF-
related ICs, servo ICs, and loader. It also carries out
interlocking control, maintenance and error log
management of each device including the optical block.
Firmware programs of the SY CPU and DSP as well as
sources of each PLD are stored in the flash memory IC602,
and the CPU loads them to each device when the power is
turned on.
The BDC IC300 and SV DSP IC400 are controlled by the
parallel CPU bus, while RF-related ICs are controlled by
the serial port through SYS PE IC700.
Adjustment values and hours meter data are stored in the
EEPROM IC4 on the SE-857 board.
PDW-700/V1 (E)