JPH0235372U - - Google Patents

Description

[Brief explanation of drawings]

All the figures relate to the present invention; FIG. 1 is a configuration circuit diagram illustrating a hard disk drive incorporating a head abnormality detection device according to the present invention, and FIG. 2 is a circuit diagram illustrating a configuration example of a read signal value detection circuit of the head abnormality detection means. Figure 3 is a waveform diagram of the main signals related to it, Figure 4 is a relationship diagram between the head and disk showing normal and abnormal head floating states, and Figure 5 is a diagram of the relationship between the head and the disk.
FIG. 3 is a waveform diagram of main signals showing operations related to the present invention of the hard disk drive shown in the figure. In the figure, 1: disk, 1a: disk substrate, 1b:
Storage medium, 1c: magnetic powder, 2: head, 2a: core, 2b: lower surface of core, 2c: notch, 2d:
Groove, 2e: Non-magnetic material for magnetic gap, 2f: Head coil, 2g: Head support arm, 3: Spindle motor, 3a: Pulse generator, 4: Drive circuit, 5: Carriage, 5a: Guide roller, 5
b: Metal band, 6: Head operation motor, 6a:
capstan, 7: drive circuit, 8: read/write circuit, 9: read signal demodulation circuit, 10: control pulse generation circuit, 11: off-track detection circuit, 12:
Processor, 13: Bus, 14: Interface, 20: Hard disk device, 21: Controller, 22: Bus, 30: Monitoring information, 31: Monitoring information for one disk surface, 40: Head abnormality detection means, 41: Read signal value detection circuit, 41a: amplifier circuit, 41b: filter circuit, 41c: rectifier circuit, 4
1d: Smooth resistance, 41e: Smooth capacitor, 41
f: AD converter, 42: software section of head abnormality detection means, 50: servo information, 51, 52:
Servo information part, 60: Track, A to C: Signal in read signal value detection circuit, CP: Clock pulse,
DS: Drive signal, HS: Head selection command, FS:
Abnormality detection signal, IDXe: external index pulse, IDXi: internal index pulse, R: disk rotation direction, RS: read signal, RV: read signal value, RW: read/write command, R3, R31
~R34: Monitoring information reading signal, R5, R51,
R52: Servo information reading signal, S3: Control pulse for reading monitoring information, S5: Control pulse for reading servo information, Td: Reading/writing period, T3: Reading period for monitoring information, T5: Reading period for servo information, WS: Writing input signal, X: head position operation direction, δ
: Flying gap of the head, φ: Magnetic flux.

Claims (1)

[Scope of utility model registration request] This is a device for detecting abnormalities that may occur in the pneumatically floating head that reads and writes information on the tracks of a hard disk drive. Monitoring information consists of a simple repeating pattern written uniformly regardless of the track, and this monitoring information is read through the head in synchronization with the rotation of the disk, and the value of the read signal is set in advance. head abnormality detecting means for determining that the head is abnormal when the disk deviates from the normal range determined by the head; and as long as the disk is in a rotating state, the head abnormality detecting means is constantly operated to detect an abnormality in the flying state of the head. A head abnormality detection device for a hard disk drive, characterized in that: