Abstract: A piezo actuator is provided between a suspension spring and a head carriage. When a predetermined track of a magnetic disk is accessed by positioning a magnetic head in the predetermined track, the piezo actuator maintains the magnetic head in an ON track state by dynamically moving a light weight head cartridge according to a servo information or dynamically moving a head assembly in the head cartridge according the servo information.

Abstract: A piezo actuator is provided between a suspension spring and a head carriage. When a predetermined track of a magnetic disk is accessed by positioning a magnetic head in the predetermined track, the piezo actuator maintains the magnetic head in an ON track state by dynamically moving a light weight head cartridge according to a servo information or dynamically moving a head assembly in the head cartridge according the servo information.

Abstract: A magnetic disk certifier includes a defect detector circuit comprising a low-pass filter for extracting a low frequency component of the read-out signal, the low frequency component containing a signal component of the error, a signal generator circuit for generating a signal having a predetermined frequency lower than the frequency of the read-out signal, a synthesizer circuit for synthesizing an output signal of the low-pass filter and the signal outputted from the signal generator circuit and a comparator for generating an error signal by comparing the synthesized signal from the synthesizer circuit with a predetermined reference level.

Abstract: A magnetic disk read/write circuit comprises a core having a pair of coils wound such that signals supplied to the coils becomes opposite in phase and a read circuit having a first input terminal connected to one of terminals of a read head through one of the coils to receive a read signal from the read head and a second input terminal connected to the other terminal of the read head through the other coil to receive the read signal from the read head or a write circuit in which the read head is a write head, the signal at the first input terminal is a signal at the first output terminal and the signal at the second input terminal is a signal at a second input terminal.

Abstract: A magnetic disk certifier includes a defect detector circuit comprising a low-pass filter for extracting a low frequency component of the read-out signal, the low frequency component containing a signal component of the error, a signal generator circuit for generating a signal having a predetermined frequency lower than the frequency of the read-out signal, a synthesizer circuit for synthesizing an output signal of the low-pass filter and the signal outputted from the signal generator circuit and a comparator for generating an error signal by comparing the synthesized signal from the synthesizer circuit with a predetermined reference level.