Abstract: Systems, devices, processes, and methods of optimizing a data storage device based on adjacent track interference (ATI) are presented. ATI can be detected by writing a specific track of a disc a number of times and measuring a bit error rate (BER) of an adjacent track. In addition, more accurate in-field simulations of ATI can be achieved by seeking to another track, such as an adjacent track, in-between each write to the specific track. Further, in a heat-assisted magnetic recording (HAMR) device, a laser bias control can be implemented during at least one of the seeks to calibrate a laser in-between each write. Even further, the seeks may be anticipatory track seeks (ATS).

Abstract: Systems, methods, devices, circuits for data processing, and more particularly to data processing including adjacent track interference mitigation.

Abstract: Apparatus and method for writing data to a data storage medium using shingled magnetic recording (SMR). In accordance with some embodiments, a transducer is positioned adjacent a recording medium. The transducer is used to write data to the medium in the form of partially overlapping tracks grouped together into bands so that a first track and a last track in a selected band are wider than remaining tracks in the selected band.

Abstract: SMR disk drives are described that adjust track pitch or magnetic write width to compensate for external temperature effects. In one embodiment track pitch is increased when the media temperature increases. The temperature of magnetic media during write operations can be determined from the drives' temperature sensor. In other embodiments track pitch is adjusted based on the magnetic write width (MWW) which is determined from read-back testing of previously written data tracks. In an alternative embodiment, the width of the MWW is adjusted instead of the track pitch. The various factors that affect the MWW that can be used to increase or decrease the MWW, including write current characteristics and when available thermal-assistance parameters.

Abstract: A shingled magnetic recording hard disk drive that uses writeable cache tracks in the inter-band gaps between the annular data bands minimizes the effect of far track erasure (FTE) in the boundary regions of annular data bands caused by writing to the cache tracks. Based on the relative FTE effect for all the tracks in a range of tracks of the cache track being written, a count increment (CI) table or a cumulative count increment (CCI) table is maintained. For every writing to a cache track, a count for each track in an adjacent boundary region, or a cumulative count for each adjacent boundary region, is increased. When the count value for a track, or the cumulative count for a boundary region, reaches a predetermined threshold the data is read from that band and rewritten to the same band.

Abstract: A shingled magnetic recording (SMR) hard disk drive (HDD) essentially eliminates the effect of far track erasure (FTE) in the boundary regions of annular data bands caused by writing in the boundary regions of adjacent annular data bands. The extent of the FTE effect is determined for each track within a range of tracks of the track being written. Based on the relative FTE effect for all the tracks in the range, a count increment (CI) table or a cumulative count increment (CCI) table is maintained for all the tracks in the range. For every writing to a track in a boundary region, a count for each track in an adjacent boundary region, or a cumulative count for the adjacent boundary region, is increased. When the count reaches a predetermined threshold the data is read from that band and rewritten to the same band.

Abstract: A disk drive includes a disk having a track that includes a data sector divided by a servo sector so that a first data sector portion is on a first side of the servo sector, and a second data sector portion is on a second side of the servo sector. The disk drive reads data by: positioning the head at a first offset position with respect to the track and reading data from the data sector. When a read error occurs between the first and second data sector portions, the disk drive: stores the data from the first data sector portion in memory, moves the head to a second offset position with respect to the track, reads data from the second data sector portion with the head at the second offset position, and stores the data read from the second data sector portion in the memory.

Abstract: An apparatus and method of reading and writing data from and to a data storage device is provided. One method of practicing the present invention comprises placing, or leaving an unused track, row or column adjacent to a medium track containing apparatus information. Another method of practicing the present invention comprises placing, or leaving an unused track, row or column adjacent to both sides of the medium track containing the apparatus information.

Abstract: A method of writing to a disc in a disc drive includes receiving data to be written to a designated area of the disc wherein the designated area has a beginning, an end, and contains a defective portion. The data is written to the disc starting from the beginning of the designated area and proceeding toward the end of the designated area. The data is written to a temporary buffer, external to the disc, upon reaching the defective portion of the designated area. Writing is then resumed, writing data to the designated area of the disc, upon passing the defective portion of the designated area.

Abstract: A magnetic recording and reproducing method comprises the steps of forming magnetic domain walls in reference positions on a magnetic recording medium having a recording layer consisting of a magnetic film in which a nucleation coercivity for changing a direction of magnetization is larger in strength than a domain wall motion coercivity for shifting the magnetic domain walls and which has substantially only magnetic regions, the recording layer having a track and the reference positions being regularly spaced in the direction of length of the track, and applying to the magnetic recording medium a recording field which is smaller in strength than the nucleation coercivity but larger than the domain wall motion coercivity to thereby shift each of the domain walls in the recording layer from its reference position forward or backward in the direction of length of the track, whereby information is recorded.

Abstract: A copyright information embedding system is provided which is designed to embed information for copyright protection into digital audio signals without deterioration of analog audio signals reproduced. The copyright information embedding system includes an A/D converter, a modulator, a level detector, and a copyright data embedding circuit. The A/D converter converts an analog audio signal into a digital signal. The modulator modulates a copyright data signal for the digital signal using spectrum spread. The level detector detects a variation in level of the digital signal. The copyright data embedding circuit divides the copyright data signal into several codes and embeds them into the digital signal each time the variation in level of the digital signal shows a preselected variation such as a rapid rise or drop.

Abstract: An alignment tape for magnetic recording and playback devices contains recorded tracks useful for aligning the tape path on a rotating drum. The recorded tracks are spaced apart a sufficient distance to avoid interference from adjacent recorded tracks when the playback head is off-track. The alignment tracks are spaced apart a distance equal to the distance normally occupied by three tracks. This ensures that interference from an adjacent track when the head is off-track is minimized or eliminated. An apparatus is disclosed for controlling the recording of the alignment tape.