Fujitsu MPF3XXXAT manual Head, Actuator

4.2.2Head

Figure 4.1 shows the read/write head structures. The Numerals 0 to 3 indicate read/write heads. These heads are raised from the disk surface as the spindle motor approaches the rated rotation speed.

MPF3102AT Model

Spindle

1

0

MPF3153AT Model

Spindle

2

1

0

Actuator

Actuator

MPF3204AT Model

Spindle Actuator

3

2

1

0

Figure 4.1 Head structure

4.2.3Spindle

The spindle consists of a disk stack assembly and spindle motor. The disk stack assembly is activated by the direct drive sensor-less DC spindle motor, which has a speed of 5,400 rpm. The spindle is controlled with detecting a PHASE signal generated by counter electromotive voltage of the spindle motor at starting. After that, the rotational speed is kept with detecting a servo information.

4.2.4Actuator

The actuator consists of a voice coil motor (VCM) and a head carriage. The VCM moves the head carriage along the inner or outer edge of the disk. The head carriage position is controlled by feeding back the difference of the target position that is detected and reproduced from the servo information read by the read/write head.

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