Multi-speed storage device
Various embodiments of the present invention are generally directed to adjusting a fly height of a transducer to enable a first data access with a storage medium rotating at a first speed, rotating the storage medium at a second speed substantially different from the first speed, and adjusting the fly height of the transducer to enable a second data access with the storage medium rotating at the second speed.
1. A method comprising:
adjusting a fly height of a transducer to enable a first data access with a storage medium rotating at a first speed;
rotating the storage medium at a second speed substantially different from the first speed;
adjusting the fly height of the transducer to enable a second data access with the storage medium rotating at the second speed; and
adaptively adjusting the fly height of the transducer and the rotating speed of the storage medium to a third speed in response to an anticipated inadvertent change in operational characteristics that would result in an insufficient supply of data from the storage medium to a host.
2. The method of claim 1 , wherein the second adjusting step comprises adjusting the fly height of the transducer via a writer heater to achieve a second fly height during said second adjusting step that is nominally equal to a first fly height achieved during the first adjusting step.
3. The method of claim 2 , wherein the second adjusting step further comprises applying a predetermined fly height adjustment value to the writer heater.
4. The method of claim 1 , wherein the transducer is configured to fly at the same nominal height adjacent the storage medium at both the first and second speeds.
5. The method of claim 1 , wherein the second speed is at least twice the first speed, and the same data on the storage medium are accessed by the transducer at each of the first and second speeds.
6. The method of claim 1 , wherein the respective first and second data accesses are made with the same data on the storage medium.
7. The method of claim 1 , further comprising prior steps of storing a first plurality of fly height adjustment values to be applied to a writer heater associated with the transducer while the medium is rotated at the first speed for different radial locations of the medium, storing a second plurality of fly height adjustment values to be applied to the writer heater while the medium is rotated at the second speed for said different radial locations, and wherein the respective first and second adjustment steps comprise application of associated fly height adjustment values from the respective first and second pluralities to obtain substantially constant fly height characteristics of the transducer at each of the first and second speeds over each of said different locations.
8. An apparatus comprising:
a rotatable storage medium;
a transducer mounted to a slider operable to provide a fluid bearing interface with the storage medium;
a writer heater interfaced with the slider to control a fly height thereof; and
a servo circuit which moves the transducer and slider across a radius of the storage medium and which maintains a continuous data transfer rate from the storage medium by adaptively adjusting the fly height of the transducer and a rotating speed of the storage medium in response to an anticipated inadvertent change in operational characteristics.
9. The apparatus of claim 8 , wherein the servo circuit is further configured to determine a fly height of the transducer in relation to a detected contact between the transducer and the medium.
10. The apparatus of claim 8 , wherein the transducer is configured to nominally fly at a constant fly height over a plurality of different rotational speeds of the medium apart from operation of the writer heater.
11. The apparatus of claim 8 , wherein the servo circuit is further configured to command a selected operational speed of the medium in relation to a content of data accessed by the transducer.
12. The apparatus of claim 8 , wherein the servo circuit is further configured to command a selected operational speed of the medium in relation to an external signal from the host device.
13. The apparatus of claim 8 , wherein user data at a first location of the medium are accessed by the transducer while the medium is rotated at a first speed, and wherein the user data at the first location are subsequently accessed by the transducer while the medium is rotated at a second speed significantly different from the first speed.
14. The apparatus of claim 8 , wherein the plurality of speeds further comprises at least one speed corresponding to a high performance mode of operation and at least one speed corresponding to a power saving mode of operation.
15. A method comprising:
rotating a storage medium at a first speed during a first operational mode;
rotating the storage medium at a second speed that is slower than the first speed during a different, second operational mode in response to an anticipated inadvertent change in operational characteristics that would result in an insufficient supply of data from the storage medium to a host; and
supporting a transducer adjacent the medium during each of the respective rotating steps to access data stored on said medium using fly height adjustment compensation to adaptively maintain a substantially constant fly height during each of the first and second modes.
16. The method of claim 15 , wherein said fly height adjustment compensation comprises providing the transducer with an associated writer heater, predetermining fly height adjustment values, and selectively applying said fly height adjustment values to maintain said substantially constant fly height.
17. The method of claim 15 , wherein said fly height adjustment compensation comprises shaping a slider of the transducer to fly at the substantially constant fly height apart from application of heating thereto.
18. The method of claim 15 , further comprising prior steps of storing a first plurality of fly height adjustment values to be applied to a writer heater associated with the transducer while the medium is rotated at the first speed for different radial locations of the medium, storing a second plurality of fly height adjustment values to be applied to the writer heater while the medium is rotated at the second speed for said different radial locations, and wherein the supporting step comprises application of associated fly height adjustment values from the respective first and second pluralities to obtain substantially constant fly height characteristics of the transducer at each of the first and second speeds over each of said different locations.
19. The method of claim 15 , wherein the servo circuit is further configured to command a selected operational speed of the medium in relation to a content of data accessed by the transducer.
20. The method of claim 15 , wherein the servo circuit is further configured to command a selected operational speed of the medium in relation to an external signal from the host device.