Control unit, storage unit, and method for manufacturing storage unit
View Patent ↗A control unit adjusts spacing between a head with a heater and a storage medium of a storage unit by controlling the power of the heater. The control unit measures first values of touchdown heater power at a first temperature set as the temperature condition. And the control unit estimates second values of the touchdown heater power at a temperature other than the first temperature set on the measurement of the first values, on the basis of a conversion equation. And the control unit determines heater power setting values to adjust the spacing between the head and the storage medium, for each of the sub-areas, on the basis of the first values and the second values.
1. A control unit for adjusting spacing between a head with a heater and a storage medium of a storage unit by controlling power of the heater, the storage medium being divided into a plurality of sub-areas, said control unit comprising:
a processor to control the control unit according to a process including:
measuring first values of touchdown heater power upon the head coming in contact with the storage medium at at least one temperature set as a temperature condition for adjusting the spacing, for each of the sub-areas;
estimating second values of the touchdown heater power at a second temperature other than the first temperature set on the measurement of the first values, on the basis of a conversion equation obtained from correlation between third values of the touchdown heater power measured in advance at the first temperature and the second temperature, for each of the sub-areas, the conversion equation converting a touchdown heater power at the first temperature to a touchdown heater power at the second temperature; and
determining heater power setting values for adjusting the spacing between the head and the storage medium, for each of the sub-areas, by using the first values and the second values.
2. The control unit according to claim 1 , wherein, for each of the sub-areas, fourth values of the touchdown heater power are measured at at least two temperatures set as the temperature condition, fifth values of the touchdown heater power at a temperature other than said at least two set temperatures are estimated by linear interpolation on the basis of correlation between the fourth values of the touchdown heater power measured, and the heater power setting values are determined by using the fourth values and the fifth values.
3. The control unit according to claim 2 , wherein, for each of the sub-areas, sixth values of the touchdown heater power are measured at all temperatures set as the temperature condition, and a value of the touchdown heater power that is not measured is estimated by at least one of the conversion equation and the linear interpolation.
4. A storage unit comprising:
a storage medium divided into plural sub-areas;
a head with a heater;
a control unit for adjusting the spacing between the head and the storage medium by controlling power of the heater, said control unit including:
a processor to control the control unit according to a process including:
measuring first values of touchdown heater power upon the head coming in contact with the storage medium at at least one temperature set as a temperature condition for adjusting the spacing, for each of the sub-areas;
estimating second values of the touchdown heater power at a second temperature other than the first temperature set on the measurement of the first values, on the basis of a conversion equation obtained from correlation between third values of the touchdown heater power measured in advance at the first temperature and the second temperature, for each of the sub-areas, the conversion equation converting a touchdown heater power at the first temperature to a touchdown heater power at the second temperature; and
determining heater power setting values for adjusting the spacing between the head and the storage medium, for each of the sub-areas, by using the first values and the second values.
5. The storage unit according to claim 4 , wherein, for each of the sub-areas, fourth values of the touchdown heater power are measured at at least two temperatures set as the temperature condition, fifth values of the touchdown heater power at a temperature other than said at least two set temperatures are estimated by linear interpolation on the basis of correlation between the fourth values of the touchdown heater power measured, and the heater power setting values are determined by using the fourth values and the fifth values.
6. The storage unit according to claim 5 , wherein, for each of the sub-areas, sixth values of the touchdown heater power are measured at all temperatures set as the temperature condition, and a value of the touchdown heater power that is not measured is estimated by at least one of the conversion equation and the linear interpolation.
7. A method for manufacturing a storage unit including a storage medium and a head with a heater for adjusting the spacing between the head and the storage medium, the storage medium being divided into a plurality of sub-areas, comprising the steps of:
measuring first values of touchdown heater power upon the head coming in contact with the storage medium at at least one temperature set as a temperature condition for adjusting the spacing, for each of the sub-areas;
estimating second values of the touchdown heater power at a second temperature other than the first temperature set on the measurement of the first values, on the basis of a conversion equation obtained from correlation between third values of the touchdown heater power measured in advance at the first temperature and the second temperature, for each of the sub-areas, the conversion equation converting a touchdown heater power at the first temperature to a touchdown heater power at the second temperature; and
determining heater power setting values for adjusting the spacing between the head and the storage medium, for each of the sub-areas, by using the first values and the second values.
8. The method for manufacturing a storage unit according to claim 7 , wherein, for each of the sub-areas, fourth values of the touchdown heater power are measured at at least two temperatures set as the temperature condition, fifth values of the touchdown heater power at a temperature other than said at least two set temperatures are estimated by linear interpolation on the basis of correlation between the fourth values of the touchdown heater power measured, and the heater power setting values are determined by using the fourth values and the fifth values.
9. The method for manufacturing a storage unit according to claim 8 , wherein, for each of the sub-areas, sixth values of the touchdown heater power are measured at all temperatures set as the temperature condition, and a value of the touchdown heater power that is not measured is estimated by at least one of the conversion equation and the linear interpolation.