Class / Patent application number | Description | Number of patent applications / Date published |
360029000 | MODULATING OR DEMODULATING | 19 |
20090268322 | Systems and Methods for Acquiring Modified Rate Burst Demodulation in Servo Systems - Various embodiments of the present invention provide systems and methods for performing modified rate burst demodulation. For example, a method for performing modified rate burst demodulation is disclosed. The method includes receiving a data input that includes a synchronization pattern, an information pattern, and a demodulation pattern. A periodic boundary is established along with a phase and frequency of a sampling clock based at least in part on the synchronization pattern. The information pattern is processed using the sampling clock to determine a location fix. The sampling clock is phase shifted by a skew amount and a phase shifted sampling clock is provided. The demodulation pattern is processed using the phase shifted sampling clock. | 10-29-2009 |
20100002325 | EMBEDDED TRACK INFORMATION FOR PATTERNED MEDIA - A bit-patterned magnetic media (BPM) includes with respect to each data track regular bit-islands having a first size and large bit-islands having a second size. The placement of the regular bit-islands and large bit-islands within each data track results in a unique pattern. An amplitude-modulated readback signal is generated in response to a transducer head moving over the bit-patterned media. Based on the amplitude-modulated readback signal, channel response circuitry detects the pattern of regular bit-islands and large bit-islands associated with a particular data track. Based on the detected pattern, the channel response circuitry is able to uniquely identify the data track. | 01-07-2010 |
20100053787 | Systems and Methods for On-The-Fly Write Pre-compensation Estimation - Various embodiments of the present invention provide systems and methods for write pre-compensation. For example, various embodiments of the present invention provide systems for on-the-fly estimation of write pre-compensation values. Such systems include a magnetic storage medium, a read/write head assembly disposed in relation to the magnetic storage medium, and an analog to digital converter that receives an analog signal from the read/write head assembly corresponding to a data set stored on the magnetic storage medium and provides a series of digital samples corresponding to the data set. The storage devices further include a read data processing circuit that receives the same series of digital samples and provides a user data output, and a pre-compensation value calculation circuit that receives the series of digital samples and provides an updated write pre-compensation value. | 03-04-2010 |
20110157736 | INTEGRATING CONTROL OF SLIDER BIAS POTENTIAL, TOUCH-DOWN DETECTION AND FLY-HEIGHT DETERMINATION IN A HDD - A hard disk drive (HDD) including a slider. The slider includes a resistive temperature detector (RTD) configured to detect a temperature generated by one or more of slider spacing and contact with a media of said HDD. HDD also includes a slider signal controller configured to control bias signal of a slider with respect to a media potential, a real-time media-disk fly-height and contact detector configured to detect one or more of temperature generated by real-time media-disk slider spacing and real-time media-disk contact, and a real-time relative fly-height determiner configured to detect real-time relative fly-height of the slider based on analysis of a modulated portion of a high-frequency signal coupled to an element of the slider. | 06-30-2011 |
20110249354 | DISK STORAGE APPARATUS AND METHOD FOR SERVO CONTROLLING - According to one embodiment, a disk storage apparatus includes a disk and a servo demodulator. The disk has a servo area, in which a first phase servo pattern, a second phase servo pattern that is in phase with the first servo pattern, and a third servo pattern that is inverse in phase to the first and second servo patterns. The third servo pattern comprises at least two phase servo pattern segments. The servo demodulator is configured to perform a phase servo demodulating process that includes integration operation on integration sections of the same ratio, using a read signal read from the servo area by a head. | 10-13-2011 |
20120162803 | DISK STORAGE DEVICE, CONTROLLER OF THE SAME, CONTROLLING METHOD PERFORMED BY THE SAME, AND ELECTRONIC DEVICE - According to one embodiment, a disk storage device includes: a disk on which a servo pattern is recorded; a head; a driver; a signal generator; a demodulator; and a controller. Position signals for detecting an offset position from a center of a track are recorded in a recording area of a servo pattern. The signal generator generates a first timing signal indicating a timing for reading the position signals. When the controller performs positional control along a virtual circular orbit of the disk, the signal generator generates a second timing signal. The period of the second timing signal for reading each of the position signals is made shorter than that of the first timing signal. A center time of the period of the second timing signal is shifted closer to a demodulation center time corresponding to a center of the recording area than that of the first timing signal. | 06-28-2012 |
20120162804 | MAGNETIC HEAD AND CARD READER EQUIPPED WITH THE MAGNETIC HEAD - A magnetic head which includes a core, a coil wound on the core, terminals to which ends of the coil are connected. The magnetic head also includes a substrate on which mounted are a demodulating electronic component for demodulating an analog output signal output from the terminals to create a digital demodulated signal, and an encrypting electronic component for encrypting the demodulated signal to create an encrypted signal. A cable electrically connects the demodulating electronic component and the terminals. A case body stores the core, the coil, the terminals, and the cable. The demodulating electronic component is mounted on one side of the substrate, and the encrypting electronic component is mounted on the other side of the substrate. The substrate is fixed to the case body so that the demodulating electronic component is placed inside the case body while the encrypting electronic component is placed outside the case body. | 06-28-2012 |
20130003209 | CHANNEL CIRCUIT AND SEEK METHOD - A channel circuit includes a reader, a decoder, a prediction module, and a seek module. The reader reads data written in a medium. The decoder performs iterative decoding of the read data. The prediction module predicts whether an early read is possible or not without waiting for arrival of the read data. The seek module continuously initiates a seek when the prediction module predicts that the read is possible. | 01-03-2013 |
20130335841 | IMPLEMENTING COMBINED PHASE AND AMPLITUDE MAGNETIC DEFECT DETECTION ON-THE-FLY - A method, apparatus, and system are provided for implementing magnetic defect location detection on-the-fly for hard disk drives. A magnetic media readback signal of a hard disk drive is demodulated to generate phase modulation (PM) and amplitude modulation (AM) signals. A new coordinate plane defined by a combined phase modulation (PM) and amplitude modulation (AM) phasor-defect detector calculation function used to locate magnetic defects on-the-fly. | 12-19-2013 |
20140111880 | MULTI-LEVEL RUN-LENGTH LIMITED FINITE STATE MACHINE FOR MAGNETIC RECORDING CHANNEL - A system is described for constructing maximum transition run modulation code based upon a multi-level run-length limited finite state machine. A processor is configured to receive information from a hard disk drive via a read channel and recover data from the hard disk drive using maximum transition run modulation code. A memory has computer executable instructions configured for execution by the processor to model a magnetic recording channel as a partial response channel, model a source of information to the magnetic recording channel to provide an optimized Markov source, and construct a maximum transition run modulation code to mimic the optimized Markov source based upon a finite state machine having a limited transition run length and a multi-level periodic structure. | 04-24-2014 |
20140233128 | Systems and Methods For Burst Demodulation - A data processing circuit with flaw robust burst field demodulation includes a burst integration circuit operable to calculate burst integration results for a servo data burst field, a comparison circuit operable to determine whether an absolute value of the burst integration results falls outside a window, and an error indicating circuit operable to indicate that a media flaw has been detected when the absolute value of the burst integration results fall outside the window. | 08-21-2014 |
20150062730 | Array-Reader Based Magnetic Recording Systems With Quadrature Amplitude Modulation - A magnetic recording system includes an array of analog inputs operable to receive analog signals retrieved from a magnetic storage medium, a quadrature amplitude modulator operable to combine the analog signals to yield a quadrature amplitude modulated signal, a quadrature amplitude demodulator operable to yield a plurality of demodulated signals from the quadrature amplitude modulated signal corresponding to each channel of the array, and a joint equalizer operable to filter the plurality of demodulated signals to yield an equalized output. | 03-05-2015 |
20150146318 | HEAD POSITION DEMODULATION METHOD AND MAGNETIC DISK DEVICE - According to one embodiment, at demodulation of an A-phase burst pattern and a B-phase burst pattern arranged in a down-track direction so as to be different from each other in phase in a cross-track direction, the demodulated position of a magnetic head is calculated based on a sin component and a cos component in the A-phase burst pattern and a sin component and a cos component in the B-phase burst pattern. | 05-28-2015 |
360030000 | Frequency | 6 |
20090086354 | SIGNAL REPRODUCING METHOD, MAGNETIC HEAD AND MAGNETIC RECORDING AND REPRODUCING APPARATUS - A magnetic head, includes a magnetic oscillation element, the oscillation frequency of which is modulated by a medium magnetic field, and a reproducing device configured to detect a phase difference between the adjacent oscillation signals derived from the magnetic oscillation element and output a phase difference signal as a reproduced signal. | 04-02-2009 |
20100157454 | HEAD-DISK CONTACT DETECTION AND WORK FUNCTION DIFFERENCE DETERMINATION - In a method of head-disk contact detection in a hard disk drive, a Radio Frequency (RF) carrier signal is injected into a slider which is flying above a surface of a disk in a hard disk drive. A modulated version of the RF carrier signal is received from the slider. The modulated version of the RF carrier signal is demodulated to achieve a demodulated signal. A signal spectrum of a range of frequencies in the demodulated signal is monitored for activity indicative of a contact between a head of the slider and the surface of the disk. An occurrence of the contact is determined based upon an occurrence of the activity. | 06-24-2010 |
20110013304 | SIGNAL REPRODUCING METHOD, MAGNETIC HEAD AND MAGNETIC RECORDING AND REPRODUCING APPARATUS - A magnetic head, includes a magnetic oscillation element, the oscillation frequency of which is modulated by a medium magnetic field, and a reproducing device configured to detect a phase difference between the adjacent oscillation signals derived from the magnetic oscillation element and output a phase difference signal as a reproduced signal. | 01-20-2011 |
20130148223 | IMPLEMENTING SPIN-TORQUE OSCILLATOR SENSING WITH ENHANCED DEMODULATOR FOR HARD DISK DRIVES - A method, apparatus, and system are provided for implementing spin-torque oscillator (STO) sensing with a demodulator for hard disk drives. The demodulator measures an instantaneous phase of the readback signal from a STO sensor and converts the readback signal into a signal that is proportional to the magnetic field affecting the STO frequency during a bit time. The converted signal is used for processing by conventional data detection electronics. | 06-13-2013 |
20130148224 | IMPLEMENTING SPIN-TORQUE OSCILLATOR SENSING WITH ENHANCED INTEGRATED DEMODULATOR FOR HARD DISK DRIVES - A method, apparatus, and system are provided for implementing spin-torque oscillator sensing with an enhanced integrated demodulator for hard disk drives. The demodulator receives an input signal from a STO read sensor having an oscillation frequency ω related to the strength of the detected magnetic signal field. The demodulator includes a pair of mixers coupled to a quadrature reference oscillator with respective quadrature components cos(ω | 06-13-2013 |
20150029608 | Array-Reader Based Magnetic Recording Systems With Frequency Division Multiplexing - A magnetic recording system includes an array of analog inputs operable to receive analog signals retrieved from a magnetic storage medium, a modulator operable to combine the analog signals to yield a frequency division multiplexed signal, a demodulator operable to yield a plurality of demodulated signals from the frequency division multiplexed signal corresponding to each channel of the array, and a joint equalizer operable to filter the plurality of demodulated signals to yield an equalized output. | 01-29-2015 |