专利检索_..脉冲调制记录或重现的（脉冲编码调制记录的入G11B20/10）专利检索_..脉冲调制记录或重现的（脉冲编码调制记录的入G11B20/10）专利检索查询_..脉冲调制记录或重现的（脉冲编码调制记录的入G11B20/10）专利检索查询分析平台

序号	专利名	申请号	申请日	公开（公告）号	公开（公告）日	发明人
181	Magnetic recording head	US30589663	1963-08-30	US3333275A	1967-07-25	GUERTH FRITZ A

182	Pulse position modulation system	US3258755D		US3258755A	1966-06-28

183	Method for servo demodulation and disk storage apparatus	US14081908	2013-11-15	US08908303B1	2014-12-09	Tomoyoshi Yamada
According to one embodiment, in a method for servo demodulation, a first demodulated signal and a second demodulated signal, which are calculated from amplitude values of burst signal patterns of a first area and a second area, are generated in order to generate a position error signal of a reader, based on a servo pattern read from a disk by the reader. Further, in the method for servo demodulation, a square-root of sum of squares of the first and the second demodulated signals is calculated, and an optimal compensation coefficient of a linearity correction function to be used in linearity compensation of the position error signal is calculated based on a maximum value and a minimum value of the square-root of sum of squares.
184	Systems and methods for acquiring modified rate burst demodulation in servo systems	US12111319	2008-04-29	US07813065B2	2010-10-12	Viswanath Annampedu; Venkatram Muddhasani; Xun Zhang
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.
185	Servo demodulating circuit and method	US11594541	2006-11-08	US07532421B2	2009-05-12	Sumio Kuroda
Servo demodulation is performed by appropriately compensating for demodulation errors caused by fluctuation of the replayed signal amplitude of a phase servo pattern. A servo demodulating circuit comprises single waveform sampling means for reading into a register a single waveform of a servo burst signal included in a phase servo signal based on a sampling clock synchronized by clock synchronization means, single waveform digitizing means for calculating an amplitude value of the single waveform of the servo burst signal from peak and bottom of the single waveform of the servo burst signal read into the register, and for standardizing a value of the register based on an amplitude value of the single waveform of the servo burst signal, and phase information calculation means for calculating phase information of the single waveform of the servo burst signal based on the value of the register standardized by the waveform digitizing means.
186	Servo demodulating circuit and method	US11594541	2006-11-08	US20070273992A1	2007-11-29	Sumio Kuroda
Servo demodulation is performed by appropriately compensating for demodulation errors caused by fluctuation of the replayed signal amplitude of a phase servo pattern. A servo demodulating circuit comprises single waveform sampling means for reading into a register a single waveform of a servo burst signal included in a phase servo signal based on a sampling clock synchronized by clock synchronization means, single waveform digitizing means for calculating an amplitude value of the single waveform of the servo burst signal from peak and bottom of the single waveform of the servo burst signal read into the register, and for standardizing a value of the register based on an amplitude value of the single waveform of the servo burst signal, and phase information calculation means for calculating phase information of the single waveform of the servo burst signal based on the value of the register standardized by the waveform digitizing means.
187	Signal reproducing method and storage apparatus	US11702798	2007-02-06	US20070171566A1	2007-07-26	Tomoaki Saito
A signal reproducing method reproduces servo information recorded on a recording medium by use of a head. A current calculation related to a current and an observer calculation related to a position and a velocity of the head are made based on reproduced servo information, and a current value for driving the head is calculated based on the above calculation result. Only computations which require a demodulation result of a present sample are made during a first time after demodulation of the position of the head to a time when the current value is output, and computations which require a demodulation result of a past sample are made during a second time other than the first time.
188	PRML based magnetic servo position demodulator	US11188199	2005-07-22	US20070019316A1	2007-01-25	David Norton
Apparatuses and methods for detecting reference marks on magnetic data storage mediums are described herein. In one variation, the apparatus comprises a magnetic servo position demodulator operable to extract information from the magnetic data storage medium utilizing Partial Response/Maximum Likelihood (PRML) technique. Synchronization marks stored within the PRML channel is then detected utilizing a digital filter. For each of the detected synchronization mark, a further refined position of the synchronization mark can be determined utilizing a mathematical prediction model.
189	Servo demodulator systems including multiple servo demodulators	US10620818	2003-07-16	US07075742B2	2006-07-11	Richard M. Ehrlich
Servo demodulation systems including multiple servo demodulators are provided. A first servo demodulator is adapted to search for a servo address mark (SAM) pattern using a first set of servo demodulation detection parameters. A second servo demodulator is adapted to search for the SAM pattern using a second set of servo demodulation parameters, wherein at least one servo demodulation parameter in the second set is different than a corresponding parameter in the first set. Example servo demodulation parameters include staring automatic gain control (AGC) values and starting phase lock loop (PLL) values.
190	Systems for searching for SAM patterns at multiple nominal frequencies	US10621048	2003-07-16	US07054083B2	2006-05-30	Richard M. Ehrlich
Systems are provided for improving servo-demodulation robustness, especially when used with a disk having zone bit recorded servo wedges. The systems include a first servo demodulator adapted to search for a servo address mark (SAM) pattern, within a servo wedge, at a first nominal frequency useful for searching for the SAM pattern if the servo wedge is within a first zone. The systems also include a second servo demodulator adapted to search for the SAM pattern, within the same servo wedge, at a second nominal frequency useful for searching for the SAM pattern if the servo wedge is within the second zone. A microprocessor can then determine which of the first and second zones a head is reading, based at least in part on which of the first and second demodulators detects the SAM pattern.
191	Methods for searching for SAM patterns using multiple sets of servo demodulation detection parameters	US10620971	2003-07-16	US20050013027A1	2005-01-20	Richard Ehrlich
Methods for searching for a servo address mark (SAM) pattern using multiple sets of servo demodulation detection parameters are provided. A SAM pattern is searched for using a first set of servo demodulation detection parameters. The SAM pattern is also searched for using a second set of servo demodulation parameters, wherein at least one servo demodulation parameter in the second set is different than a corresponding parameter in the first set. Example servo demodulation parameters include staring servo automatic gain control (AGC) values and starting servo phase lock loop (PLL) values.
192	Flexible mounting and unmounting of user removable media	US184788	1998-11-02	US6119232A	2000-09-12	William L. Duncan
A computer implemented method and apparatus for mounting a user removable media in a computer system includes acquiring a media identifier input and a function identifier input from a user of the computer system. The media identifier input identifies the user removable media, and the function identifier input specifies a mounting operation to be performed on the user removable media. The media identifier and the function identifier inputs are processed to access a system media interface of the computer system, for example, by converting the media identifier input to a physical path of the user removable media in the computer system, and determining if the physical path of the media identifier input is valid within the computer system. A simulated media event is generated to mount the user removable media in the computer system. If desired, a determination may be made whether the user has valid permission to control the user removable media identified by the media identifier input. This may be performed by reading a media permission level associated with the user removable media identified by the media identifier input, reading a user permission level associated with the user, and comparing the media permission level to the user permission level.
193	Information signal recording and reproducing system capable of recording an information signal on a medium having a limited recording band width	US426789	1989-10-25	US5132957A	1992-07-21	Akira Mashimo
An information signal recording and reproducing system for recording and reproducing an information signal on and from a recording medium comprises a modulation circuit for modulating the information signal to form a modulated signal involving a number of pulses, a first frequency divider triggered responsive to a leading edge of the pulses in the modulated signal to produce a first frequency-divided signal having a frequency substantially lower than that of the modulated signal, a second frequency divider triggered responsive to a trailing edge of the pulses in the modulated signal to produce a second frequency-divided signal having a frequency substantially lower than that of the modulated signal, a recording device for recording the first and second frequency-divided signals on the recording medium, a reproducing device for detecting the first and second frequency-divided signals recorded on the recording medium to produce a first reproduced frequency-divided signal and a second reproduced frequency-divided signal, a synthesizing circuit supplied with the first and second reproduced frequency-divided signals to produce a synthetic modulated signal corresponding to the modulated signal by performing an exclusive-or operation of the first and second frequency-divided signals, and a demodulating circuit supplied with the synthetic modulated signal to produce a reproduced information signal.
194	Method and apparatus for processing an error flag of a PCM signal	US784593	1985-10-04	US4660200A	1987-04-21	Hiroo Okamoto; Masaharu Kobayashi
Method and apparatus for reproducing a PCM signal are disclosed. The PCM signal comprises a plurality of word-interleaved frames. Each frame comprises a plurality of data blocks and a parity block. Each data block comprises a plurality of words, each word comprises an upper symbol and a lower symbol arranged symbol by symbol. A plurality of upper symbols included in different blocks and a plurality of lower symbols included in the same word form a parity code generated from the symbols in the respective symbol sequences and a plurality of error detection/correction blocks. In the error flag processing of the PCM signal, the input PCM signal is reproduced, errors are detected and corrected based on the corresponding parity codes for a plurality of upper symbol error detection/correction sequences and a plurality of lower symbol error detection/correction sequences, error flags indicating the number of errors detected and the number of errors corrected are generated for the error detection/correction sequences based on the result of the error detection/correction, a flag indicating a maximum significant value is detected from two flags generated for the upper and lower symbol error detection/correction sequence of the same word and selecting that flag as a common flag to both sequences.
195	Magnetic recording and reproducing apparatus	US531184	1983-09-09	US4481548A	1984-11-06	Tuneo Yanagida
A still video signal is modulated to a PDM signal by a pulse duration modulator. The PDM signal is recorded by a perpendicular magnetic recording head on a recording medium of perpendicular magnetic anisotropy according to the perpendicular magnetic recording method. The PDM signal recorded on the recording medium is reproduced by a perpendicular magnetic reproducing head.
196	Recording and playback modulation method and apparatus	US812356	1977-07-01	US4186411A	1980-01-29	Toshihiko Numakura
Overlapping, minute regions of magnetization in a recording medium, which are produced during recording and cause distortion of the played back signal, are reduced by encoding the signal in a pulse signal. The time between pulses is varied according to the amplitude of the signal to be recorded, and when this pulse signal is recorded, the minute regions are reduced to elemental size. Thus they overlap less and do not distort the reproduced signal by offsetting the zero level.
197	Differential duration demultiplexing method and system	US681832	1976-04-30	US4051539A	1977-09-27	Leslie A. Geddes; Joe D. Bourland
A demultiplexing method and system is disclosed utilizing a differential duration technique. Data that have been conventionally encoded utilizing a technique wherein variations in time contain the essential information, such as can be accomplished by systems wherein data are encoded by modulating either the spacing between pulses or the width of the pulses, is decoded by differential duration demultiplexing to reduce errors caused by time distortion introduced prior to recovery of the data. Time distortion errors are reduced by sensing both the pulses and intervals following the pulses in the data train and deriving decoded data from the difference therebetween.
198	Apparatus for recording and reproducing analog data	US25769972	1972-05-30	US3840890A	1974-10-08	SUNDERLAND J
Apparatus for recording and reproducing analog data, the apparatus having means for generating a modified ramp waveform and means in circuit for comparing an input signal representing the analog data with the modified ramp waveform and for producing an output signal to be recorded wherein the output signal has characteristics representative of the analog data. Apparatus for reproducing the analog data receives a signal from a recording device and includes pulse discriminator means for receiving an amplified signal from the recording device, a bistable circuit in operative relationship with the discriminator means and filtering means for filtering a carrier waveform from the output of the bistable circuit and for providing a signal that accurately reproduces the analog data originally received.
199	Electrical data handling apparatus	US68707757	1957-09-30	US3010094A	1961-11-21	MACARTHUR JOHN L

200	Pulse width recording	US70413457	1957-12-20	US3009025A	1961-11-14	KENJIRO TAKAYANAGI; SUSUMN NOMURA

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