Provided is an amplifier circuit including an inverting input terminal configured to receive a first voltage, an output terminal, and a class A amplifier circuit configured to generate, at the output terminal, an output voltage that changes in reverse polarity with respect to the first voltage, in which a bias current of an output stage of the class A amplifier circuit changes according to the first voltage.

An actuator pivot assembly for a multi-actuator shared shaft data storage device may include a shared pivot shaft around which a first rotary actuator assembly is coupled, with a first bearing assembly interposed therebetween with a first bearing preload, and around which a second rotary actuator assembly is coupled, with a second bearing assembly interposed therebetween with a second different bearing preload. Furthermore, the first bearing assembly may have a first bearing span and the second bearing assembly may have a second bearing span that is different from the first bearing span. Each of the foregoing bearing features may thereby assist with spacing apart the structural resonance frequencies of the actuator assemblies to inhibit transmission of vibration between the actuators during operation.

A split-shaft pivot assembly for a dual-actuator data storage device may include a first pivot shaft having a threaded stud extending from one end and an attachment flange at the other end, and a second pivot shaft having a threaded bore at one end a structurally equivalent attachment flange at the other end, where the two pivot shafts are attached to each other by threading the stud into the bore. A first bearing assembly may be affixed with a first preload around the first pivot shaft, and a second bearing assembly may be affixed with a second different preload around the second pivot shaft. The pivot assembly may further include an elastomeric damper positioned within an annular groove formed in, and around the threaded stud of, the first pivot shaft. Such features may serve to inhibit and/or damp transmission of vibrational energy among the actuators through the shared split-shaft.

A multi-actuator hard disk drive includes a lower actuator with a corresponding voice coil motor assembly (VCMA), a coaxial upper actuator with a corresponding VCMA, and a central extended stiffener plate positioned between the upper and lower VCMAs and extending beyond the pivot area at least to an area adjacent to the disk stack. Use of an extended stiffener plate enables some control over the direct and coupled plant transfer functions, while effectively providing a base support structure for the upper VCMA and cover support structure for the lower VCMA.

A split-shaft pivot assembly for a dual-actuator data storage device may include a first pivot shaft having a threaded stud extending from one end and an attachment flange at the other end, and a second pivot shaft having a threaded bore at one end a structurally equivalent attachment flange at the other end, where the two pivot shafts are attached to each other by threading the stud into the bore. A first bearing assembly may be affixed with a first preload around the first pivot shaft, and a second bearing assembly may be affixed with a second different preload around the second pivot shaft. The pivot assembly may further include an elastomeric damper positioned within an annular groove formed in, and around the threaded stud of, the first pivot shaft. Such features may serve to inhibit and/or damp transmission of vibrational energy among the actuators through the shared split-shaft.

An actuator pivot assembly for a multi-actuator shared shaft data storage device may include a shared pivot shaft around which a first rotary actuator assembly is coupled, with a first bearing assembly interposed therebetween with a first bearing preload, and around which a second rotary actuator assembly is coupled, with a second bearing assembly interposed therebetween with a second different bearing preload. Furthermore, the first bearing assembly may have a first bearing span and the second bearing assembly may have a second bearing span that is different from the first bearing span. Each of the foregoing bearing features may thereby assist with spacing apart the structural resonance frequencies of the actuator assemblies to inhibit transmission of vibration between the actuators during operation.

A storage device performs a background operation involving seeking a read/write head between inner and outer diameters of a disk of the storage device. During the seeking, adjacent test tracks are written at a diameter between the inner and outer diameters of the disk. The adjacent test tracks are written using varying levels of laser power applied to the disk via the read/write head. An optimum value of the laser power is determined based on reading at least one of the adjacent test tracks.

A multi-actuator hard disk drive includes a lower actuator with a corresponding voice coil motor assembly (VCMA), a coaxial upper actuator with a corresponding VCMA, and a central extended stiffener plate positioned between the upper and lower VCMAs and extending beyond the pivot area at least to an area adjacent to the disk stack. Use of an extended stiffener plate enables some control over the direct and coupled plant transfer functions, while effectively providing a base support structure for the upper VCMA and cover support structure for the lower VCMA.

Rotational latency is reduced in a standard conventional form factor HDD system by replacing, for example, the prior art rotary arm actuator of a conventional HDD, with one or more belts and pulleys and one or more read/write heads mounted on, or otherwise associated with the belts. Multiple scaled iterations facilitate energy savings and power optimized systems, without compromise to data access performance.

Rotational latency is reduced in a standard conventional form factor HDD system by replacing, for example, the prior art rotary arm actuator of a conventional HDD, with one or more belts and pulleys and one or more read/write heads mounted on, or otherwise associated with the belts. Multiple scaled iterations facilitate energy savings and power optimized systems, without compromise to data access performance.