Fujitsu MHM2100AT - Mobile 10 GB Hard Drive Product Manual page 55

Theory of Device Operation
4.1 Outline
This chapter consists of two parts. First part (Section 4.2) explains mechanical
assemblies of the disk drive. Second part (Sections 4.3 through 4.7) explains a
servo information recorded in the disk drive and drive control method.
4.2 Subassemblies
The disk drive consists of a disk enclosure (DE) and printed circuit assembly
(PCA).
The DE contains all movable parts in the disk drive, including the disk, spindle,
actuator, read/write head, and air filter. For details, see Subsections 4.2.1 to 4.2.5.
The PCA contains the control circuits for the disk drive. The disk drive has one
PCA. For details, see Sections 4.3.
4.2.1 Disk
The DE contains disks with an outer diameter of 65 mm and an inner diameter of
20 mm. The MHL2300AT have three disks and MHM2200AT and
MHM2150AT have two disks and MHM2100AT have one disk.
The head contacts the disk each time the disk rotation stops; the disk surface is
durable at least 50,000 CSS (Contact Start/Stop) or more.
Servo data is recorded on each cylinder (total 66). Servo data written at factory is
read out by the read head. For servo data, see Section 4.7.
4.2.2 Head
Figure 4.1 shows the head structures. MHL2300AT has 6 heads and
MHM2200AT has 4 heads and MHM2150AT has 3 heads and MHM2100AT has
2 heads. These heads are raised from the disk surface as the spindle motor the
rated rotation speed.
4-2 C141-E104-03EN