1.2 Configuration of Optical Disk Drive
SCSI controller circuit section
MPU
ODC
SCSI I/F 
DSP User Logic LSI i/f
F-ROM
D-RAM
Driver circuit section
Read Amp
Power Amp
Filter
Sensor
Motor Driver
Mecha section
Head section
Laser Diode
Photo Diode
APC Amp
LPC Amp
Head Amp
Actuator section Focus Act. Track Act. Spindle Motor Temperature Sensor
Bias Coil
Eject Motor
Cartridge Sensor
Figure 1.4 Block diagram of the control circuit section
The control circuit consists of a SCSI controller, which controls operations between the SCSI interface and the drive interface, and a device circuit section, which controls the drive circuit.
(1) SCSI controller circuit section
The SCSI controller circuit, which uses an LSI for improved reliability, controls the drive through SCSI interface control,
(2) Drive circuit section
The drive circuit section consists of the laser diode light emitting control circuit, signal reproduction circuit, servo/seek control circuit, rotation control circuit, and other control circuits. In particular, the servo/seek control circuit consists of a DSP (digital signal processor) for circuit reduction and the realization of a simple configuration.
The drive circuit section performs the seek, erase, record, and playback operations while controlling the focus tracking of the beam.
