Fujitsu MHS2020AT, Product Manual

Page: 56 / 254

Theory of Device Operation
4-2 C141-E171-03EN
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 MHS2060AT and MHS2040AT have two disks and MHS2030AT
and MHS2020AT have one disk.
Servo data is recorded on each cylinder (total 120). 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. MHS2060AT has 4 heads and
MHS2040AT has 3 heads and MHS2030AT and MHS2020AT have 2 heads.