Head positioning servo system for disk drives
Thermal compensation for disk pack systems
Positioning system and method particularly useful for magnetic disk drives
ApplicationNo. 081651 filed on 08/04/1987
US Classes:360/77.11, Continuous servo signal360/77.03, By nonmagnetic sensing (e.g., optical, capacitive)360/77.04, By memory storage of repeatable error or correction360/78.11Including nonmagnetic position sensing
ExaminersPrimary: Psitos, Aristotelis M.
Assistant: Garland, Steven R.
Attorney, Agent or Firm
Foreign Patent References
International ClassG11B 005/596
Foreign Application Priority Data1986-08-27 JP
AbstractA magnetic disc apparatus wherein off-track quantities are stored with regard to reference servo tracks formed circularly in divided data areas on a magnetic disc and, at the time of displacing the magnetic head, the head is shifted an extent of the stored off-track quantity after being once positioned by a head position detector. Gradients of the off-track quantities corresponding to tracks at individual temperatures in the apparatus are previously stored and, after the actual temperature is detected by means of a temperature sensor, the off-track quantity relative to the reference servo track is corrected in accordance with the gradient of the off-track quantity to the relevant track at the detected temperature, whereby just tracking is achieved. The magnetic head can be positioned exactly with respect to a desired data track while the head displacement time is shortened. Furthermore, data can be written in the entire length of each circular data track to enhance the efficiency of utilizing the magnetic disc, and high-precision tracking is attainable with the off-track quantity reduced to zero in any data track.
Field of SearchRotary carrier
By nonmagnetic sensing (e.g., optical, capacitive)
By memory storage of repeatable error or correction
By tracking signal recorded on or immediately beneath surface
Including nonmagnetic position sensing
For rotary carrier (e.g., disc)
Continuous servo signal
Distinct servo sector
By recorded servo reference or address signal