# US 12,112,778 B2 · Data storage device with adjacent track interference-aware servo trajectories > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,112,778 B2 - Document ID: US12112778B2 - Status: Granted - Kind: B2 - Application number: 18/232,073 - Filed: 2023-08-09 - Published: 2024-07-04 - Granted: 2024-10-08 - Earliest claimed: 2022-12-30 - Assignees: Western Digital Technologies, Inc. - Applicants: Western Digital Technologies, Inc. - Inventors: Wayne H. Vinson - Web page: https://patentgrep.com/patent/US12112778B2 ## CPC - G11B 5/59688: {Servo signal format patterns or signal processing thereof, e.g. dual, tri, quad, burst signal patterns} - G11B 5/59627: {Aligning for runout, eccentricity or offset compensation (G11B5/5534, G11B5/59677, G11B5/59688 take precedence)} - G11B: INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER (recording measured values in a way that does not require playback through a transducer G01D9/00; recording or playback apparatus using mechanically marked tape, e.g. punched paper tape, or using unit records, e.g. punched or magnetically marked cards G06K; transferring data from one type of record carrier to another G06K1/18; circuits for coupling output of reproducer to radio receiver H04B1/20; gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor H04R) ## Abstract Various illustrative aspects are directed to a data storage device, comprising one or more disks; an actuator mechanism configured to position a selected head among one or more heads proximate to a corresponding disk surface of the one or more disks; and one or more processing devices. The one or more processing devices are configured to detect adjacent track interference (ATI) due to a write operation in an adjacent sector to a subject sector on the corresponding disk surface; and to generate a readback servo trajectory for the subject sector, based on a position error signal (PES) for the subject sector, a PES for the adjacent sector, and the ATI. ## Claims ### Claim 1 A data storage device, comprising: one or more disks; an actuator mechanism configured to position a selected head among one or more heads proximate to a corresponding disk surface among the one or more disks; and one or more processing devices configured to: detect adjacent track interference (ATI) due to a write operation in an adjacent sector to a sector subjected to a write or read operation on the corresponding disk surface; and generate a readback servo trajectory for the sector subjected to the write or read operation, based on a position error signal (PES) for the sector subjected to the write or read operation, a PES for the adjacent sector, and the ATI due to the write operation in the adjacent sector. ### Claim 2 (depends on 1) The data storage device of claim 1, wherein the one or more processing devices are further configured to generate the readback servo trajectory such that the readback servo trajectory yields a higher signal-to-noise ratio (SNR) for the sector subjected to the write or read operation than performing the read operation of the sector subjected to the write or read operation based on a track-center servo trajectory. ### Claim 3 (depends on 1) The data storage device of claim 1, wherein the one or more processing devices are further configured to store the readback servo trajectory for the sector subjected to the write or read operation in a non-volatile memory component. ### Claim 4 (depends on 1) The data storage device of claim 1, wherein the one or more processing devices are further configured to use the readback servo trajectory for the sector subjected to the write or read operation for performing the read operation of the sector subjected to the write or read operation. ### Claim 5 (depends on 1) The data storage device of claim 1, wherein the one or more processing devices are further configured to store the PES for the sector subjected to the write or read operation prior to the write operation in the adjacent sector. ### Claim 6 (depends on 5) The data storage device of claim 5, wherein the one or more processing devices are further configured to store the PES for the sector subjected to the write or read operation in a non-volatile memory component. ### Claim 7 (depends on 1) The data storage device of claim 1, wherein the ATI is a first ATI detected in the adjacent sector on a first side of the sector subjected to the write or read operation, and the readback servo trajectory is an initial readback servo trajectory, wherein the one or more processing devices are further configured to: detect a second ATI due to a write operation in a second adjacent sector on a second side of the sector subjected to the write or read operation; and generate a modified readback servo trajectory for the sector subjected to the write or read operation based on the initial readback servo trajectory, the PES for the second adjacent sector, and the second ATI. ### Claim 8 (depends on 7) The data storage device of claim 7, wherein the one or more processing devices are further configured to designate two bits per sector subjected to the write or read operation in a data store for indicating whether ATI has been detected on the first side and on the second side of the sector subjected to the write or read operation. ### Claim 9 (depends on 1) The data storage device of claim 1, wherein the sector subjected to the write or read operation is one of a plurality of subject sectors comprised in a subject track, and wherein the one or more processing devices are further configured to store, in a memory component, respective servo trajectories for the plurality of subject sectors comprised in the subject track. ### Claim 10 (depends on 9) The data storage device of claim 9, wherein the memory component is a first memory component, wherein the one or more processing devices are further configured to store the respective servo trajectories for the plurality of subject sectors comprised in the subject track from the first memory component to a contiguously readable block in a non-volatile memory component. ### Claim 11 (depends on 1) The data storage device of claim 1, wherein the one or more processing devices are further configured to record an indication of whether a subject track that comprises the sector subjected to the write or read operation has been subject to new write operations in one or more further sectors of the subject track subsequent to generating the readback servo trajectory for the sector subjected to the write or read operation. ### Claim 12 (depends on 11) The data storage device of claim 11, wherein the one or more processing devices are further configured, in response to the subject track having been subject to a new write operation in one or more further sectors of the subject track subsequent to generating the readback servo trajectory for the sector subjected to the write or read operation, to use conventional PES values for the read operation of the subject track. ### Claim 13 (depends on 11) The data storage device of claim 11, wherein the one or more processing devices are further configured, in response to the subject track having been subject to a new write operation in one or more further sectors thereof subsequent to generating the readback servo trajectory for the sector subjected to the write or read operation, to generate a readback servo trajectory, for the subject track, using both data from a first memory component on the write operation in the one or more further sectors of the subject track, and the readback servo trajectory for the sector subjected to the write or read operation from a second memory component that comprises a non-volatile memory component. ### Claim 14 (depends on 1) The data storage device of claim 1, wherein the one or more processing devices are further configured, in response to a discontinuity in a nominal trajectory between the sector subjected to the write or read operation and a previous sector or a following sector, to apply a filter to the readback servo trajectory. ### Claim 15 (depends on 1) The data storage device of claim 1, wherein the one or more processing devices are further configured to convert the readback servo trajectory to a per-servo-ID servo control signal. ### Claim 16 A method comprising: detecting, with one or more processors, adjacent track interference (ATI) due to a write operation in an adjacent sector to a sector subjected to a write or read operation on a disk surface of a data storage device; and generating, with one or more processors, a readback servo trajectory for operating a head proximate to the sector subjected to the write or read operation, based on a position error signal (PES) for the sector subjected to the write or read operation, a PES for the adjacent sector, and the ATI. ### Claim 17 (depends on 16) The method of claim 16, further comprising generating the readback servo trajectory such that the readback servo trajectory yields a higher signal-to-noise ratio (SNR) for the sector subjected to the write or read operation in the read operation than performing the read operation of the sector subjected to the write or read operation based on a track-center servo trajectory. ### Claim 18 (depends on 16) The method of claim 16, further comprising storing the readback servo trajectory for the sector subjected to the write or read operation in a non-volatile memory component. ### Claim 19 One or more processing devices comprising: means for detecting adjacent track interference (ATI) due to a write operation in an adjacent sector to a sector subjected to a write or read operation on a disk surface of a data storage device; and means for generating a readback servo trajectory for operating a head proximate to the sector subjected to the write or read operation, based on a position error signal (PES) for the sector subjected to the write or read operation, a PES for the adjacent sector, and the ATI. ### Claim 20 (depends on 19) The one or more processing devices of claim 19, further comprising means for generating the readback servo trajectory such that the readback servo trajectory yields a higher signal-to-noise ratio (SNR) for the sector subjected to the write or read operation in the read operation than performing the read operation of the sector subjected to the write or read operation based on a track-center servo trajectory.