Abstract: A display element of an optical stack assembly in an augmented reality (AR) near-eye display device may be protected against ultraviolet (UV) and/or infrared (IR) exposure through one or more protective coatings on various surfaces of the elements of the optical stack assembly. A photochromic coating on one of the surfaces of the elements of the optical stack assembly may also be used instead of or in addition to the protective coatings.

Abstract: A storage device has a storage medium, a plurality of read-write mechanisms, a quality monitoring and book-keeping unit and a scheduling unit. The plurality of read-write mechanisms is coupled to the storage medium. The quality monitoring and book-keeping unit is coupled to the plurality of read-write mechanisms and is adapted to monitor at least one performance parameter associated with each read-write mechanism during operation. The scheduling unit is coupled to the quality monitoring and book-keeping unit. The scheduling unit is adapted to rank each of the plurality of read-write mechanisms according to the at least one performance parameter and to responsively schedule use of a read-write mechanism according to its rank.

Abstract: A storage device has a storage medium, a plurality of read-write mechanisms, a quality monitoring and book-keeping unit and a scheduling unit. The plurality of read-write mechanisms is coupled to the storage medium. The quality monitoring and book-keeping unit is coupled to the plurality of read-write mechanisms and is adapted to monitor at least one performance parameter associated with each read-write mechanism during operation. The scheduling unit is coupled to the quality monitoring and book-keeping unit. The scheduling unit is adapted to rank each of the plurality of read-write mechanisms according to the at least one performance parameter and to responsively schedule use of a read-write mechanism according to its rank.

Abstract: An apparatus comprises a storage medium, a recording head, a source of electromagnetic radiation, and a control circuit for modulating the source of electromagnetic radiation in response to a static deviation of a spacing between the recording head and the storage medium. A method of compensating a static deviation of a spacing between a recording head and a storage medium performed by the apparatus, and a method of precompensating for nonlinear transition shifts in a heat assisted magnetic recording system, are also provided.

Abstract: An apparatus comprises a data storage medium having a plurality of servo sectors and a plurality of data sectors, wherein each of the servo sectors includes a phase locked loop field and a track identification field, a controller for controlling the position of a recording head with respect to the data storage medium, and a servo demodulator for recovering timing information from both the phase locked loop field and the track identification field, and for producing a timing estimate. The method performed by the apparatus is also included.

Abstract: A method of timing recovery comprises receiving an input signal, sampling the input signal to produce a plurality of signal samples, detecting the samples to produce an output signal, and controlling timing of the sampling in response to a maximum-likelihood estimation of timing error between an actual sampling time instant and a desired sampling time instant. Apparatus that performs the method is also provided.

Abstract: A storage device has a storage medium, a plurality of read-write mechanisms, a quality monitoring and book-keeping unit and a scheduling unit. The plurality of read-write mechanisms is coupled to the storage medium. The quality monitoring and book-keeping unit is coupled to the plurality of read-write mechanisms and is adapted to monitor at least one performance parameter associated with each read-write mechanism during operation. The scheduling unit is coupled to the quality monitoring and book-keeping unit. The scheduling unit is adapted to rank each of the plurality of read-write mechanisms according to the at least one performance parameter and to responsively schedule use of a read-write mechanism according to its rank.

Abstract: A parallel channel timing recovery circuit. The parallel timing recovery circuit comprises multiple prefilters receiving parallel channel outputs and providing prefilter outputs. Multiple sampling filters receive the prefilter outputs and provide multiple discrete time signal samples. A self-timing circuit has multiple inputs receiving the multiple discrete time signal samples. The self-timing circuit provides a sampling control output to the sampling filters. The sampling control output is based on a composite of the multiple discrete time signal samples. Each of the sampling filters generates a discrete time signal sample based on the sampling control output and the prefilter outputs.

Abstract: In a method for generating a confidence level of a position error signal (PES) component that is indicative of a quality of the PES component, a PES component is generated using position signal samples of a read back signal corresponding to a servo burst pattern. Next, a noise level corresponding to noise in the read back signal is extracted using the position signal samples. A confidence level is then generated based on the PES component and the noise level. A system for performing the method includes a transformation block, a position error signal (PES) component extractor, a noise extractor, and a confidence level generator. The transformation block is configured to receive position signal samples of a read back signal corresponding to a servo burst pattern taken at a sampling frequency. A transformed domain representation of the position signal samples is then generated by the transformation block based on the sampling frequency and the servo burst pattern.

Abstract: A method includes the steps of receiving a signal indicative of data bits, and performing per survivor processing-iterative timing recovery (PSP-ITR) on the received signal to generate probabilities of the data bits. To perform PSP-ITR on the received signal, the signal can be processed using a per survivor processing-soft decision algorithm (PSP-SDA) which jointly performs timing recovery and equalization in accordance with embodiments of the present invention. The soft decision algorithm (SDA) can be, for example, a Bahl, Cocke, Jelinek, and Raviv (BCJR) algorithm or a Soft Output Viterbi Algorithm (SOVA) modified in accordance with the concepts of the present invention such that it is configured to implement per survivor processing (PSP) to jointly perform timing recovery and equalization.

Abstract: A servo track sensing system receives equalized servo data from a servo demodulator and corrects for radial incoherence in the servo data. The system has a radial incoherence estimator that receives the equalized servo data and provides a radial incoherence estimate. A sequence detector receives the equalized servo data and the radial incoherence estimate, and provides a sequence detector output. A correlator receives the sequence detector output and provides correlator output data. The correlator output data has a reduced level of errors due to radial incoherence.