US 11,900,965 B2
Z-height control for disc drive using servo wedge timing
Xiong Liu, Singapore (CN); Choon Kiat Lim, Singapore (CN); June Christian Ang, Singapore (CN); and Yichao Ma, Singapore (CN)
Assigned to Seagate Technology LLC, Fremont, CA (US)
Filed by Seagate Technology LLC, Fremont, CA (US)
Filed on Feb. 14, 2022, as Appl. No. 17/670,627.
Prior Publication US 2023/0260547 A1, Aug. 17, 2023
Int. Cl. G11B 21/24 (2006.01)
CPC G11B 21/24 (2013.01) 20 Claims
OG exemplary drawing
 
5. A data storage device comprising:
a data storage disc comprising:
a data track;
a top surface and a bottom surface, each of the top and bottom surfaces being parallel to an x-y plane; and
a servo wedge comprising:
a top surface boundary of the servo wedge; and
a bottom surface boundary of the servo wedge;
wherein the top surface boundary and the bottom surface boundary are spaced apart by a distance along the data track;
an actuator arm assembly comprising:
a first actuator arm supporting a first head configured for interaction with the top surface, the first actuator arm spaced at a Z-height from the top surface;
a second actuator arm supporting a second head configured for interaction with the bottom surface; and
a feedback and control system configured to:
employ a transfer function relating the Z-height to the distance; and
change the Z-height based on the transfer function.