Methods and apparatus to control head expansion in multi-head hard-disk drives
OwnerToru Takeuchi, Motomu Hashizume +1inventors
InventorsToru Takeuchi, Motomu Hashizume, Hiroyuki Mukai
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Abstract
Methods and apparatus to control head expansion in multi-head hard-disk drives are disclosed. An example control system for use in a multi-head hard-disk drive includes a first sensor to provide a first feedback signal indicating a status of a first head; a second sensor to provide a second feedback signal indicating a status of a second head; and a shared calculation unit to selectively receive one of the first and second feedback signals for a feedback process to control an expansion of the first and second heads.
Claims20
A control system for use in a multi-head hard-disk drive, comprising:
- a first sensor to provide a first feedback signal indicating a status of a first head;
- a second sensor to provide a second feedback signal indicating a status of a second head;
- and
- a shared calculation unit to selectively receive one of the first and second feedback signals for a feedback process to control an expansion of the first and second heads.
A control system for use in a multi-head hard-disk drive, comprising:
- first and second heads, both including a resistive element to control a thermal expansion of the first and second heads;
- a reference generator associated with a dummy head to generate at least one reference signal to be used by the first and second heads during a startup period;
- and
- a shared calculation unit to selectively receive at least one feedback signal from one of the first head, the second head, or the dummy head to implement a feedback process.
A control system for use in a multi-head hard-disk drive, comprising:
- first and second heads, both including a resistor coupled to a driver to control a power level delivered to the resistor;
- a logic unit to select one of the first and second heads for a feedback process;
- a shared multiplier to receive one or more feedback signals from the selected head during the feedback process, wherein the shared multiplier is to generate an actual power signal indicative of a status of the selected head;
- a shared amplifier, coupled to the shared multiplier, to generate a control signal to be received by the driver of the selected head, wherein the control signal is based on a comparison between the actual power signal and a desired power signal conveyed to the shared amplifier via a digital-to-analog converter;
- a first capacitor coupled to the driver of the first head;
- and
- a second capacitor coupled to the driver of the second head, wherein the first and second capacitors are to store the control signal generated during the feedback process to provide the control signal to the driver of the unselected one of the first and second heads.
Dependencies are inferred from the claim text.