Abstract: A control device, a method of controlling the control device and recording medium are provided. Ranges of movement of a plurality of servo control systems are effectively used. A controller generates a corrected trajectory in which a high frequency component is removed from a first inverse kinematics trajectory so that no phase delay occurs as a command trajectory of a first servo control system.

Abstract: A PWM modulation circuit controls low-side transistors of three phases to all be in an ON state when a brake current flows; controls, in a period in which a brake current flows in a first direction in one phase, a transistor for sensing in that one phase to be in an ON state; and controls, in a period in which a brake current flows in the first direction in two phases, transistors for three phases to be in an OFF state. When the brake current is to flow, sense-phase control circuits for the three phases control a transistor for sensing, in a phase in which the brake current flows in a sink direction, to be into an ON state, and controls the transistor for sensing in a phase in which the brake current flows in an opposite direction, to be into an OFF state.

Abstract: Pseudorandom bit sequences are recorded to a heat-assisted recording medium at a laser power that is stepped while recording the pseudorandom bit sequences. The pseudorandom bit sequences are read from the heat-assisted recording medium to determine timing differences between bits written before and after the laser power is stepped. A thermal gradient of bits written to the heat-assisted recording medium is determined based on the timing differences.

Abstract: In one embodiment, a system includes a magnetic head having a plurality of write transducers and a plurality of read transducers. Each read transducer is configured to read data from a sequential access medium after being written thereto by a corresponding write transducer. The system also includes a controller and logic integrated with and/or executable by the controller. The logic is configured to read, using the plurality of read transducers, encoded data from a plurality of tracks of the sequential access medium simultaneously. The logic is also configured to determine that one or more tracks of the sequential access medium are dead within a sliding window. Moreover, the logic is configured to rewrite a set of encoded data from the one or more dead tracks to live tracks in a rewrite area of the sequential access medium. Other systems, methods, and computer program products are described according to more embodiments.

Abstract: A method of forming a recording head for use with a data storage medium in a data storage device. The method includes forming first and second writers of different target geometries. A first recording measurement is performed on one or more storage media using the first writer. A second recording measurement is performed on the one or more storage media using the second writer. Based on a comparison of the first and second recording measurements to a predetermined quantity, either the first writer or the second writer is selected to be operational in the data storage device.

Abstract: An electronic device that includes an external storage medium connection unit to which an external storage medium is connected; a detection unit that detects whether or not demonstration data is stored in the external storage medium connected to the external storage medium connection unit; and an operation mode control unit that causes the device to operate in a demonstration mode in a case where the demonstration data is stored in the external storage medium connected to the external storage medium connection unit, and causes the device to operate in a normal mode in a case where the external storage medium is not connected to the external storage medium connection unit and no demonstration data is stored in the external storage medium connected to the external storage medium connection unit.

Abstract: Disclosed herein, among other things, are systems and methods for eavesdropping on a data stream for hearing assistance devices. One aspect of the present subject matter includes a hearing assistance system for a wearer including a Bluetooth host device having a transmitter configured to send data including one or more encoded audio streams, and a data channel having an advertisement that includes frequency information, frequency hop sequences, information for decoding audio streams, and security keys for decoding audio stream information. The system also includes one or more Bluetooth slave devices identified by the Bluetooth host device. The Bluetooth slave devices are configured to actively participate in a connection with the host device to aid the host transmitter in deciding which frequencies to use for frequency hopping and in determining which frequencies are being interfered with and should not be included in a channel map, according to various embodiments.

Abstract: Narrow band dwell occurs when air bearings corresponding to a set of read and/or write heads within a hard disc drive remain within a fixed narrow band of one or more storage platters for an extended period of time. The air bearings displace lubricant on the storage platters and may redeposit the lubricant as droplets on the platters. The presently disclosure technology is directed to monitoring a hard disc drive for narrow band dwell, and in some implementations, implementing operations to mitigate narrow band dwell. More specifically, the presently disclosure technology may detect an overflying air-bearing slider position, apply a lubrication film displacement formula to a narrow band of the storage platter, apply a lubrication film reflow formula to one or more other narrow bands of the storage platter, and track lubrication film thickness over time in each of the narrow bands of the storage platter.

Abstract: Embodiments described herein provide an apparatus that is operable with a storage system. The storage system includes a controller operable to assign a pointer to a first track of a magnetic disk when data is written to the first track. The pointer points to the end of the data in the first track. The controller is also operable to detect a successive write to an earlier written portion of the first track, to update a location of the pointer based on the successive write to the earlier written portion of the first track, to increment a write count of the first track based on the successive write to the earlier written portion of the first track, and to rewrite a track adjacent to the first track when the write count breaches a threshold number.

Abstract: A method is disclosed for establishing a fly height parameter for a hard disc drive. The method includes receiving a set of testing data associated with the hard disc drive and subjecting the hard disc drive to a fly-height test at a first, nominal temperature to generate fly-height data. Based on the set of testing data and the fly-height data, the method includes predicting the hard disc drive's fly-height data for a fly-height test at a second temperature different from the first, nominal temperature. The method further includes establishing the fly-height parameter for the hard disc drive in response to the fly-height data and the predicted fly-height data.

Abstract: Described is a tape library system that generally comprises a plurality of tape drives and a data bus that links a host computer system to a first tape drive address and a second tape drive address. However, the first tape drive address points to a first controller and switch system that assumes the identity of one of the tape drives. The first controller and switch system is linked to a first tape drive adapted to cooperate with a first type of tape cartridge and a second tape drive adapted to cooperate with second type of tape cartridge. The second tape drive address points to a second controller and switch system that assumes the identity of a different one of the tape drives. The second controller and switch system is linked to a third tape drive adapted to cooperate with the first type of tape cartridge and a third tape drive adapted to cooperate with the second type of tape cartridge.

Abstract: An example tape drive includes a magnetic tape head, an actuator, and a controller. The magnetic tape head includes a data write element to write a data track including data onto magnetic tape. The data track includes a non-trimming portion and a trimmable portion. The magnetic tape head also includes a data read element to read the data written to the non-trimming portion of the data track to verify the accuracy of the data. The controller positions the magnetic tape head via the actuator to allow (i) the data write element to write the first data track, and (ii) the data read element to read the second portion of the first data track. From the read data, a determination may be made as to whether the data was written to the non-trimming portion of the data track with a threshold level of accuracy.

Abstract: A slider configured for heat-assisted magnetic recording comprises a magnetic writer, a near-field transducer, and an optical waveguide coupling the near-field transducer to a light source. The writer is situated proximate the near-field transducer at an air bearing surface of the slider and comprises a first return pole, a second return pole, and a write pole situated between and spaced apart from the first return pole and the second return pole. A structural element is situated at or near the air bearing surface between the write pole and one of the first and second return poles. The structural element comprises a cavity. A thermal sensor is disposed in the cavity. The thermal sensor is configured for sensing contact between the slider and a magnetic recording medium, asperities of the medium, and output optical power of the light source.

Abstract: According to one embodiment, a system includes a head, where the head includes: an optical signal source configured to emit a first optical signal, and a near-field transducer (NFT) configured to focus the first optical signal on a moving ferroelectric storage medium positioned below the head. The system also includes a detector operatively coupled to the head, where the detector is configured to detect a second optical signal generated in and reflected from the ferroelectric storage medium, and where the second optical signal has twice the optical frequency as the first optical signal.

Abstract: A recording head includes a waveguide configured to deliver light from a light source to a media-facing surface of the recording head. A near-field transducer is at the media-facing surface the proximate the waveguide. The near-field transducer includes a plasmonic structure with at least two opposing internal surfaces. A dielectric material fills a region between the at least two opposing internal surfaces. A dielectric slit extends between the at least two opposing internal surfaces. The dielectric slit is substantially parallel to the media-facing surface and includes a transparent material with a refractive index different than that of the dielectric material.

Abstract: A Data Storage Device (DSD) includes a magnetic storage medium and a head configured to read and write data using a current default write policy that affects an amount of power output by at least one write-assistive component of the head. One or more experimental writes are performed by writing data on the magnetic storage medium using an experimental write policy for the at least one write-assistive component, and the data is read from the magnetic storage medium. An experimental performance of the one or more experimental writes is evaluated based on the reading of the data. An experimental prediction value is determined indicating a predicted usable life of the head based on the evaluation of the experimental performance. Based on the experimental prediction value, it is determined whether to change the current default write policy for the at least one write-assistive component for future non-experimental writes.

Abstract: This disclosure describes apparatuses and techniques for multi-channel servo demodulation. Multiple servo demodulation channels enable additional information to be obtained during the self-servo writing process, such as relative positions of multiple read heads and tracking of multiple servo patterns. This additional information enhances accuracy for self-servo writing and can lead to higher recording densities in media drives, and thus more storage with little or no additional cost.

Abstract: A library control device moves a desired record medium from a magazine, which is configured to load a plurality of record media into a plurality of slots, to a drive so as to read or write data. The library control device stores identifications of record media in correlation with slots loading recording media. Upon detecting a malfunction in reading or writing data with a record medium, an operator needs to extract the record medium from the magazine. At this time, the library control device rewrites the identification of a slot, which is stored in correlation with the record medium subjected to extraction, with the identification of a predetermined slot so as to move the record medium to the predetermined slot. Thus, it is possible for an operator to extract the record medium detecting a malfunction from the predetermined slot without making any mistake.

Abstract: A recording head has a waveguide core with an input facet at an input surface. The waveguide core extends to a near-field transducer at a media-facing surface of the recording head. First and second cladding regions are co-planar with and on either cross-track side of the waveguide core. First and second pseudo-slab regions are co-planar with and on outer cross-track sides of the respective first and second cladding regions. The first and second pseudo-slab regions have an index of refraction higher than that of the first and second cladding regions. The first and second pseudo-slab regions confine and channel stray light away from the near-field transducer.

Abstract: A computer-implemented method for screening a multichannel head, according to one embodiment, includes measuring a channel signal to noise ratio value for each read transducer over a plurality of sense currents, wherein each transducer is one of a plurality of transducers in a multichannel head. The measured channel signal to noise ratio values are compared to a specification of a pre-defined value. The multichannel head is dispositioned to enable the multichannel head to perform to the specification of the pre-defined value, if possible.