公开(公告)号：CA1079845A

公开(公告)日：1980-06-17

申请号：CA256686

申请日：1976-07-09

Applicant: IBM

Inventor： CASE WILLIAM J P ,  COMMANDER ROBERT D

IPC: G05D3/12 ,  G05B11/36 ,  G11B5/596 ,  G11B21/10 ,  G11B5/56 ,  G11B17/00

Abstract: DATA STORAGE APPARATUS Data track position information for data tracks on a stack of recordingdisks is provided by servo information pre-recorded on one surface of the stack. In addition, each data track on the remaining surfaces of the stack has servo information relative to that track pre-recorded in sectors around the track. Track access operations are controlled using track crossing information derived from the pre-recorded servo information on the servo surface and track following operations are controlled in a closed loop servo system using on-track position information derived from the sectored servo tracks associated with the track being followed. The bandwidth of the position error signal derived from the sectored servo information is increased by adding high frequency components obtained from the continuous servo information on the servo surface.

公开(公告)号：CA1097805A

公开(公告)日：1981-03-17

申请号：CA281860

申请日：1977-06-30

Applicant: IBM

Inventor： CASE WILLIAM J P

IPC: G05D13/62 ,  G05D3/12 ,  G11B5/55 ,  G11B5/596 ,  G11B17/00 ,  G11B21/08 ,  G11B17/08

Abstract: Servo apparatus for controlling position and movement of a transducer over information tracks recorded on a movable record medium and containing pre-recorded servo information which when read by the transducer generates servo signals, comprises control means arranged to receive the servo signals and to generate a position error signal therefrom indicative by its magnitude and polarity of the degree and direction of off-set of the head from the on-track position. The position error signal is supplied during track following operations to an actuator mechanism connected to the transducer so that the actuator mechanism is energized in response to the position error signal to move the transducer in a direction to reduce the off-set of the transducer from the on-track position. The control means is further arranged during track access operations to sample the servo signals from the transducer at times calculated to coincide with the on-track positions of the transducer moving across the tracks and to supply position error signals derived from the sampled servo signals to the actuator mechanism which is energized in response thereto to change the velocity of the transducer across the tracks by an amount determined by the position error signals. UK9-75-014