Redundant Or Complimentary Tracks Patents (Class 360/47)
  • Patent number: 5422761
    Abstract: A magnetic disk drive includes redundant data written at a plurality of out of phase angular locations to reduce the latency and enhance performance during a read operation. The loss of recording capacity is reduced by increasing the data density to achieve the same soft error rate standard required for single recording. Dual recording also allows different recording codes to be used at the duplicated locations to thereby have the more highly stressed code words occur at different locations in the data to further reduce the possibility of an error. The redundant recording can be used in one portion of the media and normal recording used in another media portion to enable selection of the recording technique in accordance with the type of data being stored. The size of the normal and redundant recording portions can be controlled by the format operation and the user of the disk drive can intervene to designate the size of the redundant and normal media recording portions effected during the format operation.
    Type: Grant
    Filed: November 20, 1992
    Date of Patent: June 6, 1995
    Assignee: International Business Machines Corporation
    Inventors: Nathaniel C. Anderson, Mohammed A. Hajji, Hal H. Ottesen, Michael J. Ross
  • Patent number: 5390313
    Abstract: A data storage system with data mirroring and reduced access time data retrieval includes at least one pair of rotating data storage media each having a plurality of generally identical data records. Each rotating data storage medium includes position indicators, for providing one or more indications of the rotational position of each of the rotating data storage media with respect to its associated fixed position read/write mechanism. A position monitor receives the rotational position indications from each rotating data storage medium and computes and monitors the rotational position of each rotating storage medium with respect to its associated read/write mechanism.
    Type: Grant
    Filed: September 24, 1990
    Date of Patent: February 14, 1995
    Assignee: EMC Corporation
    Inventors: Moshe Yanai, Natan Vishlitzky, Bruno Alterescu, Daniel Castel
  • Patent number: 5369652
    Abstract: A data storage system has error detecting and correcting system having three error codes. The data are arranged logically as a three-dimensional array consisting of a plurality of logically rectangular blocks of data. Each block of data has columns and rows of data. A first error code that corrects errors creates a first redundancy in each of the columns. A like-positioned block row of data in each of the blocks constitutes an array row of data. The array rows are grouped into sets of array rows, the number of array rows in each set vary inversely with a number of tracks of a record medium that concurrently receive the data for recording. Each set of data are recorded serially by bit in respective tracks of the tape record medium. Before recording, the block rows are logically rotated (end-around shifted) within each of the array rows.
    Type: Grant
    Filed: June 14, 1993
    Date of Patent: November 29, 1994
    Assignee: International Business Machines Corporation
    Inventors: Charles E. Bailey, Ernest S. Gale, Carl A. Hassell, Scott J. Schaffer, Sushama M. Paranjape, Stephen C. West
  • Patent number: 5339319
    Abstract: In a rotary type storage apparatus and a control method thereof, a plurality of concentric or spiral information tracks are set and also each of the plural information tracks is subdivided into a plurality of sectors along a circumferential direction, which constitute a plurality of information recording planes. Also, in this apparatus and method, there are provided a plurality of read/write heads employed at each of the information recording planes and accessible to the information tracks, and also a head drive mechanism for positioning these plural read/write heads to the information tracks. At least one of the plural information recording planes corresponds to such a recording plane where a substitution information track has been set, on which a substitution sector corresponding to a failed sector present at another information recording plane is recorded.
    Type: Grant
    Filed: July 2, 1991
    Date of Patent: August 16, 1994
    Assignee: Hitachi, Ltd.
    Inventors: Yuji Yamane, Toshimitsu Kaku, Yasushi Fukuda, Hitoshi Komatsu, Nobuhiro Matsumura, Shigenori Okamine, Kiyoshi Matsumoto, Soichi Isono, Kunihiko Kizaki
  • Patent number: 5239430
    Abstract: In a digital information signal reproducing apparatus in which a first digital audio signal and a second digital audio signal having the same contents are recorded on two oblique tracks which are close to each other on a record tape while the latter is run at a normal speed, and in which the first and second digital audio signals are reproduced from the tape by plural rotary heads; a head position controller is operative to control a scanning position of each of the rotary heads so that the latter scan the tracks during variable speed reproduction when the tape is run at a speed different from the normal speed, and to cause the heads to periodically jump over a plurality of the tracks; a detector detects when the rotary heads controlled by the head position controller jump over the plurality of tracks; and a processor responsive to the detector for switching the first digital audio signal and the second digital audio signal, as in a cross-fading operation, for a predetermined period when a jump is detected an
    Type: Grant
    Filed: September 25, 1990
    Date of Patent: August 24, 1993
    Assignee: Sony Corporation
    Inventors: Yoshinori Koishikawa, Nobuhiro Chiba, Yoichiro Asato
  • Patent number: 5237466
    Abstract: A data processing system is disclosed having a direct access storage device (DASD) subsystem comprising a number of separate physical housings, each housing having a number of disk supporting spindles mounted therein. The velocity of rotation of the spindles within a housing is synchronized, and the rotational position of the spindles may be locked into a fixed relationship. When number N of disk supporting spindles are provided, spindle rotation is synchronized, and mirrored data files are written out of phase by 360/N degrees, thereby providing reduced latency time during a subsequent read operation, while at the same time providing data integrity through the use of redundant data files.
    Type: Grant
    Filed: November 2, 1989
    Date of Patent: August 17, 1993
    Assignee: International Business Machines Corporation
    Inventors: Thomas W. Glaser, Richard Greenberg, Hjalmar H. Ottesen
  • Patent number: 5204708
    Abstract: The reliability of data transfer between stages of photographic filmstrip use and processing is enhanced by magnetically recording a limited data set repetitively along a wide track in a frame of the filmstrip. Plural laterally offset magnetic read heads monitor the data in the magnetic track and provide output data signals on parallel independently operating channels. The data content of the output data signals is examined to determine whether the data of an individual data signal contains corruption error. The combined linear and parallel redundancy of the system tends to ensure successful data transfer despite a less than perfect head-to-film interface and other data corrupting influences.
    Type: Grant
    Filed: December 20, 1991
    Date of Patent: April 20, 1993
    Assignee: Eastman Kodak Company
    Inventors: Arthur A. Whitfield, Michael L. Wash, Fernando G. Silva, Paul L. Taillie
  • Patent number: 5193164
    Abstract: Data deskewing apparatus includes two, byte organized random access memories for storing, aligning and then reading out channels of data which were originally skewed when read in from a multitrack magnetic recorder system. While write-in operations on skewed data are taking place in one of the random access memories (RAM), read-out operations on skew-corrected data, which had been written in on the previous cycle, are taking place in the other RAM. On the completion of a write in/read out cycle, the roles of the RAM's are interchanged, and the process repeated.
    Type: Grant
    Filed: October 22, 1990
    Date of Patent: March 9, 1993
    Assignee: Eastman Kodak Company
    Inventor: Russell D. Shon
  • Patent number: 5187511
    Abstract: A camera using film having a magnetic memorizing portion that includes a plurality of frames. The camera includes a writing device for writing the same information onto the same frame of the magnetic memorizing portion a plurality of times, and a varying device for automatically varying the number of times of writing by the writing device in conformity with the substance or degree of importance of the information.
    Type: Grant
    Filed: April 18, 1991
    Date of Patent: February 16, 1993
    Assignee: Canon Kabushiki Kaisha
    Inventor: Kenichiro Amano
  • Patent number: 5162954
    Abstract: An index pulse generator in a magnetic storage system reads data from a surface in the magnetic storage system and produces an index pulse. An incrementing sequence of non-zero codes, with redundancy, is written in a series of consecutive servo data frames, immediately preceding, leading up to, and including a specific servo index frame. Error tolerant circuitry reads and decodes the servo frame data, maintains a count of non-zero codes encountered, and generates an index pulse provided that both the desired count of non-zero codes has been reached and that a minimum number of matches between the non-zero frame counter and the actual frame decodes has been satisfied.
    Type: Grant
    Filed: July 31, 1990
    Date of Patent: November 10, 1992
    Assignee: Seagate Technology Inc.
    Inventors: Jeffrey A. Miller, Dennis D. Duffy
  • Patent number: 5146574
    Abstract: A programmable element sequence selection circuit which selects a repeatable sequence of elements from a plurality of elements is provided. The sequence selection circuit includes a sequence storage circuit into which a sequence of element identifiers is loaded and accessed.
    Type: Grant
    Filed: June 27, 1989
    Date of Patent: September 8, 1992
    Assignee: SF2 Corporation
    Inventors: Kumar Gajjar, Anh Nguyen
  • Patent number: 5088081
    Abstract: In a RAID level 5 disk drive subsystem, one or more additional disk drives, called "reserve" disks are intercoupled to the array of disk drives and a control system is included for storing recovered digital data on the additional disk drive if a sector on one of the disk drives becomes defective. The system reduces the number of disk accesses required to obtain the information stored on the defective sector. Once the information has been recovered, it is then stored on the "reserve" disk. Thereafter, whenever this information is required, the system reads the required information from the "reserve" disk, instead of going through an entire recovery process for the defective sector. Since the recovery process can take a time that is greater than several disk access times, the present invention improves the speed and the availability of data.
    Type: Grant
    Filed: March 28, 1990
    Date of Patent: February 11, 1992
    Assignee: Prime Computer, Inc.
    Inventor: William Farr
  • Patent number: 5019920
    Abstract: In this invention, pack data of a character mode including a character code is generated by a sub-code processor. The pack data is continuously recorded on a magnetic tape for a plurality of frames by rotary heads. When the pack data of the character mode is played back by the rotary heads, a controller detects the character code included in this pack data and supplies the detected code to a display to display corresponding characters.
    Type: Grant
    Filed: April 6, 1990
    Date of Patent: May 28, 1991
    Assignee: Casio Computer Co., Ltd.
    Inventors: Itsuro Yoshimoto, Kuniyoshi Otsuki
  • Patent number: 4903198
    Abstract: A magnetic disc unit device controlling system and method are disclosed in which a magnetic disc unit controller for selecting any one of a plurality of magnetic disc units and exchanging information between a computer and a selected disc unit is provided with a memory for storing substitute track tables indicative of substitute track positions corresponding to defective tracks in the disc units. The substitute track table is accessed prior to sending positioning instructions to the selected disc unit. If a substitute track exists, the address of the substitute track is sent to the selected disc unit as a positioning instruction. If there is no substitute track, the received positioning information is passed to the selected disc unit as a positioning instruction.
    Type: Grant
    Filed: September 30, 1982
    Date of Patent: February 20, 1990
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Hiroshi Iwasaki
  • Patent number: 4873588
    Abstract: An apparatus for storing digital data which is applied to a PCM audio tape recorder incorporates a data input circuit to receive data blocks each having block address data identifying the block, main data, and redundancy data forming an error detection/correction code together with data including block address data for detecting the presence/absence of errors in the block address data; an error detector to detect the presence/absence of errors in the block address data by use of the redundancy data and to produce an error detection signal when any error is detected; a first write address generator to generate first write address data; a first RAM to store the main data among the data block address to the first write address data; a second write address generator to generate second write address data; a second RAM to store the first write address data from the first write address generator according to the second write address data when the address data is determined to have no error by the error detector; a s
    Type: Grant
    Filed: December 23, 1987
    Date of Patent: October 10, 1989
    Assignee: Sony Corporation
    Inventor: Akihiko Hiramatsu
  • Patent number: 4853798
    Abstract: A tape player includes digital and analog reproducing sections for playing back a magnetic tape having recorded thereon encoded digital data arranged in data blocks and an analog signal running parallel to the digital data. A switching circuit in the digital reproducing section includes an error-detecting circuit that indicates the presence of errors or data drop-outs and a width detector that provides an initial error signal when a predetermined consecutive number of data blocks contain errors or are not being reproduced. A decoder provides decoded digital information and a remaining error signal when an uncorrected error is encountered. The remaining error signal is generated with a predetermined delay after the digital data is read from the tape. If the initial error signal is present when the remaining error signal is generated, an AND circuit and a flip-flop in the switching circuit generate a switching signal to substitute the analog signal for the digital signal.
    Type: Grant
    Filed: July 21, 1983
    Date of Patent: August 1, 1989
    Assignee: Sony Corporation
    Inventors: Yujio Fukuju, Makoto Niiro
  • Patent number: 4794468
    Abstract: A magnetic disk contains video signals, representing an image, recorded on some tracks thereof in the form of digital signals, and also contains video signals, representing the same image, recorded on other tracks thereof. A recording apparatus receives analog video signals representative of an image, and converts the received signals into associated digital data to be temporarily stored in a storage. The data stored in the storage is read out to be recorded on tracks of the magnetic disk, and also to be converted into corresponding analog signals to be recorded on other tracks thereof.
    Type: Grant
    Filed: November 10, 1987
    Date of Patent: December 27, 1988
    Assignee: Fuji Photo Film, Co. Ltd.
    Inventor: Makoto Murakoshi
  • Patent number: 4772963
    Abstract: Apparatus for enhancing the bit error rate performance of a storage medium, such as magnetic tape, magnetic disk, optical disk, or an equivalent thereof, includes two data transmission channels for recording in duplicate a stream of data bits corresponding to an information-bearing signal, each recorded bit stream being potentially influenced by a pattern of statistically distributed recording surface defects. During playback, error detection and correction circuitry for each channel provides an alarm signal synchronized with each uncorrected error condition in the corresponding stream of playback bits. A control circuit, responsive to the alarm signals from each channel, serves to interleave error-free bits from one channel, to the exclusion of error bits from the other channel, to provide a single continuous stream of relatively error-free bits corresponding to the information-bearing signal recorded.
    Type: Grant
    Filed: October 23, 1986
    Date of Patent: September 20, 1988
    Assignee: Datatape Incorporated
    Inventors: Leo T. Van Lahr, Levi H. Robinson
  • Patent number: 4667317
    Abstract: A method for storing and reproducing data by means of a standard compact-disk digital audio player. The bit groups in which the data words are contained are recorded at least three times, the analog output signal of the player being sampled and digitized during reproduction.
    Type: Grant
    Filed: June 13, 1983
    Date of Patent: May 19, 1987
    Assignee: U.S. Philips Corporation
    Inventor: Constant P. M. J. Baggen
  • Patent number: 4656536
    Abstract: In a helical-scan tape recorder, a digital signal having a series of M identification words of N bits each is generated. One of the N-bit words is a discrimination word identifying a particular combination of the other N-bit words. The M words are organized into J groups of I words each (where J.times.I=M) and recorded with an information signal at spaced intervals within each of a series of sectors defined along each track of a recording tape so that the word groups are interleaved with the information signal and each of the recorded sub-blocks can be traced substantially simultaneously by a transducer head during a search mode. At least one of the word groups includes data bits identifying distinct, but mutually closely related items of information and discrimination bits which identify the data bits. During search mode, distribution bits can be detected with the data bits of the same word group to allow the closely related items of information to be displayed.
    Type: Grant
    Filed: February 26, 1986
    Date of Patent: April 7, 1987
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Mitsunobu Furumoto, Hiroshi Taniguchi
  • Patent number: 4631723
    Abstract: A disk drive of a mass storage subsystem includes areas on a disk surface wherein a vendor-generated defective sector log, a software-generated defective sector log and an alternate sector log are stored. A random access memory (RAM) stores a copy of the defective sector logs. During a seek operation, firmware tests the defective sector logs in RAM to generate the alternate sector log for that cylinder number. During the read or write operation, the alternate sector log is checked before processing the sector to determine if it is a defective sector. If the sector is defective, the head is positioned to another cylinder at a head and sector address read from the alternate sector log.
    Type: Grant
    Filed: June 8, 1984
    Date of Patent: December 23, 1986
    Assignee: Honeywell Information Systems Inc.
    Inventors: Donald J. Rathbun, Bruce H. Tarbox, Taian Su
  • Patent number: 4630140
    Abstract: A data recording/reproducing apparatus which uses a recording medium having a data recording area divided into a plurality of sectors, each sector having an address section in which a first address signal is recorded and a data recording section, wherein a second address signal is added to data to be recorded, the second address signal representing an address of a sector in which the data is to be recorded, the data combined with the second address signal is encoded for error compensation and is recorded in the recording mode, and the second address signal reproduced with the data from the data recording section in the reproduction mode is used to discriminate an address of a target sector for reproduction. The sector address is obtained with the same level of precision as that of the reproduced data, thereby performing precise sector control and preventing data loss.
    Type: Grant
    Filed: April 5, 1984
    Date of Patent: December 16, 1986
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Tatuo Sugimura, Isao Satoh, Makoto Ichinose, Yuzuru Kuroki
  • Patent number: 4616272
    Abstract: A digital signal reproducing apparatus comprises a reproducing head for reproducing from a magnetic tape digital signals which are magnetically recorded on n tracks of the magnetic tape, where n is a natural number greater than one, the magnetic tape has a guard band separating each of two adjacent tracks among the n tracks, the reproducing head comprises n reproducing element groups provided in correspondence with the n tracks and each of the n reproducing element groups comprises a plurality of reproducing elements arranged in the tape width direction over a range of a corresponding track and guard bands on both sides thereof, a selecting circuit for selectively obtaining outputs of those reproducing elements opposing a uniform part of the magnetic field intensity distribution of the corresponding track among outputs of the plurality of reproducing elements in each of the n reproducing element groups, which selecting circuit is provided for each of the n reproducing element groups, and an adder for adding o
    Type: Grant
    Filed: March 12, 1985
    Date of Patent: October 7, 1986
    Assignee: Victor Company of Japan, Ltd.
    Inventor: Masaru Moriyama
  • Patent number: 4590531
    Abstract: A pulse code modulated audio signal transmission system which compensates for signal interference in the pulse code modulated audio signal. The system includes a first device for receiving an audio signal and for converting the audio signal into a pulse code modulated audio signal, and a second device for receiving the audio signal and for producing an auxiliary signal corresponding to the audio signal but having a smaller bandwidth than the audio signal. A transmission circuit is connected to the first and second devices for receiving the pulse code modulated audio signal and the auxiliary signal and for producing an output signal which comprises the audio signal with portions of the audio signal which contain interference being substituted with corresponding portions of the auxiliary signal.
    Type: Grant
    Filed: August 16, 1984
    Date of Patent: May 20, 1986
    Assignee: Telefunken Fernseh und Rundfunk GmbH
    Inventors: Hans-Joachim Platte, Walter Voessing, Gunter Oberjatzas, Ernst Schroder
  • Patent number: 4587577
    Abstract: A tape position data recording and reproduction method whereby the start points of all programs recorded on the tape can readily be determined merely by playing the tape for a very short time in the reproduction mode. Position data related to a present program and position data related to all subsequent programs are repeatedly recorded at predetermined positions in digital data recording tracks, which are provided as extensions of the tracks containing the video signal. Once the numerical value indicative of the start position of the desired program has been determined, the tape can readily be advanced to that point.
    Type: Grant
    Filed: February 11, 1985
    Date of Patent: May 6, 1986
    Assignee: Pioneer Electronic Corporation
    Inventor: Taiji Tsunoda
  • Patent number: 4517612
    Abstract: An apparatus for reproducing information from a track of a magnetic record carrier by means of a reproducing head divided into two reproducing portions. The apparatus comprises an amplifier circuit having a pair of input terminals, connected to the outputs of the two reproducing portions, a first signal combination unit, at least one variable gain amplifier and an output terminal. The controllable amplifier is connected between the output of the signal combination unit and the output terminal of the amplifier circuit. The gain of the amplifier is controlled in such a way that upon application of the two signals to the input terminals of the amplifier circuit, a signal is obtained on the output terminal having an amplitude u which is in a fixed ratio to the amplitude of the larger of the two signals applied to the two input terminals.
    Type: Grant
    Filed: July 22, 1982
    Date of Patent: May 14, 1985
    Assignee: U.S. Philips Corporation
    Inventors: Albert M. A. Rijckaert, Edmond de Niet
  • Patent number: 4511933
    Abstract: For a controlled positioning of a read element relative to a track to be read during the read-out of such a record carrier, low-frequency tracking signals may be recorded in the tracks. Instead of adding separate tracking signals to the information signal, these tracking signals are represented by the d.c. content of the information signal. During conversion of the information words of the information signal into channel words steps are therefore taken to provide two channel words whose d.c. content is equal but opposite for each information word. The choice between these two channel words is made depending on a control signal which depends on the desired tracking signal.
    Type: Grant
    Filed: January 13, 1983
    Date of Patent: April 16, 1985
    Assignee: U.S. Philips Corporation
    Inventors: Martijn H. H. Hofelt, Edmond de Niet, Albert M. A. Rijckaert
  • Patent number: 4506306
    Abstract: The concept of the disclosed invention is to interleave a data bit stream with itself in such a way that the respective interleaved portions are displaced from each other, within the medium, by a distance corresponding to at least the statistical maximum size of the defects. In the event, during playback, that a dropout should occur, that dropout--inherently--must affect both interleaved portions. Therefore, by continuously delaying timewise one such interleaved playback portion relative to the other for a time sufficient to bring the two playback portions into sync with each other, the original bit stream may be reconstituted by toggling back and forth between the two playback portions each time a dropout is detected in either playback portion.
    Type: Grant
    Filed: November 8, 1982
    Date of Patent: March 19, 1985
    Assignee: Eastman Kodak Company
    Inventor: Dominique H. Veillard
  • Patent number: 4499584
    Abstract: A method and apparatus is provided for detecting and rejecting spurious sals that may arise in incoming data. A remotely disposed data producing sensor for each sensor data channel and a single blind data channel extend to a receiver or a recorder. A data link is provided linking each sensor channel to the recorder and a one-shot multivibrator generates a sensor channel pulse whenever a signal having less than a predetermined rise time and exceeding a predetermined magnitude comes through the sensor data channel. Another one-shot multivibrator coupled to the blind channel generates a blind channel pulse whenever a signal satisfies the same conditions as for the sensor channel. An AND gate associated with each sensor data channel initiates an interruption of the data link for the duration of a coincident receipt of the sensor channel pulse and the blind channel pulse to connect a d.c.
    Type: Grant
    Filed: May 26, 1983
    Date of Patent: February 12, 1985
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventor: Robert F. Howarth
  • Patent number: 4494155
    Abstract: The concept of the invention is to format any bit stream which is to be recorded into a succession of data blocks, each of which corresponds lengthwise to at least the length of the largest defect statistically known to exist in the surface. The data blocks are grouped into data segments, with each data segment (1) being of a length corresponding to no more than the minimum length statistically known to exist between defects and (2) comprising (at least) two less data blocks (which shall be hereinafter sometimes referred to as "vacant blocks") than may be accommodated within a data segment.
    Type: Grant
    Filed: November 8, 1982
    Date of Patent: January 15, 1985
    Assignee: Eastman Kodak Company
    Inventor: Dominique H. Veillard
  • Patent number: 4484238
    Abstract: A unique dual track recording technique is described in which complementarily magnetically poled regions are simultaneously written in adjacent positions in two parallel tracks. Multi-track recording of magnetic data transitions in oppositely poled matched zones in the separate tracks provides a high flux coupling to a magnetic sensor. The sensor is exposed to the combined flux from both tracks. This also provides a high degree of data redundancy in the event of small physical anomalies in the magnetic medium or writing anomalies in one track or the other. Because a large magnetic field may be coupled, a magnetic sensor may be positioned at some substantial distance above the magnetic medium on which the data is recorded. This overcomes a significant problem in data reading and writing. The present limits of proximity to the magnetic medium of the sensor head or write head have been reached and still higher data density is desired.
    Type: Grant
    Filed: June 15, 1982
    Date of Patent: November 20, 1984
    Assignee: International Business Machines Corporation
    Inventor: Albert W. Vinal
  • Patent number: 4328580
    Abstract: The present invention involves an apparatus and method for processing of digital information that includes duplication of information from each channel of a multi-channel recorder on main and backup tracks and provides a combination of error detection apparatus and procedures where data groupings or words on each track are individually subject to four separate tests for detecting errors and provides, from that analysis, for a selection of most likely correct data for further processing. Additionally, further system reliability is obtained by providing circuitry whereby a detected error activates a selection of data groupings coming before and after the detected error, providing where appropriate, for switching from main to backup track data over a certain number of data groupings.
    Type: Grant
    Filed: July 6, 1979
    Date of Patent: May 4, 1982
    Assignee: Soundstream, Inc.
    Inventors: Thomas G. Stockham, Jr., Bruce C. Rothaar
  • Patent number: 4302783
    Abstract: At least one bit of a digital signal including a plurality of bits to be simultaneously recorded on a plurality of tracks of a magnetic tape, is recorded on at least two tracks located at opposite sides with respect to a reference track. The reference track carries a reference signal utilized for producing a synchronous signal with which the plurality of bits are reproduced in synchronization. When reproducing, a.c. signals derived from the two corresponding tracks having the simultaneously recorded bits are added to each other whereby the phase difference of the plurality of bits with respect to the reference signal is compensated while drop out phenomenon is reduced.
    Type: Grant
    Filed: December 5, 1979
    Date of Patent: November 24, 1981
    Inventors: Soichiro Mima, Hiroshi Matsushima, Yasuharu Shimeki, Nobuyoshi Kihara
  • Patent number: 4224642
    Abstract: For recording and reproducing analog audio signals by a pulse-code modulation scheme so as to permit effective compensation for dropout errors, an incoming audio signal is sampled, and the analog samples are converted into a sequence of coded pulse groups or words. These words are grouped into successive notional blocks, and the odd and the even words, for example, of each block are divided into sub-blocks, as by sequentially writing the words of each block in successive storage locations in a memory and by retrieving the odd, and then the even, words from the memory. The sub-blocks of the successive word blocks are recorded in different regions on a recording medium such as magnetic tape. After being reconverted into an electrical signal from the recording medium, the words of the sub-blocks of each block are rearranged into the original order, as by use of a second memory, prior to the reconstruction of the analog audio signal.
    Type: Grant
    Filed: May 11, 1978
    Date of Patent: September 23, 1980
    Assignee: TEAC Corporation
    Inventors: Akinori Mawatari, Hirohisa Yamaguchi, Kenji Nakamura, Satoshi Uchiumi
  • Patent number: 4202018
    Abstract: The present invention involves apparatus and techniques for converting analog data, preferably audio signals, to digital information, which digital information is preferably recorded from two separate main channels onto main tracks and includes a third or backup track for recording thereon partial or most significant portions of that information recorded on the main tracks.
    Type: Grant
    Filed: September 27, 1978
    Date of Patent: May 6, 1980
    Assignee: Soundstream, Inc.
    Inventor: Thomas G. Stockham, Jr.
  • Patent number: 4199793
    Abstract: A magnetic tape recording and reproducing apparatus has a head assembly comprising a plurality of transducing heads, and guide means arranged so that the heads are spaced apart by a distance which is great enough so that only one head is affected by a blemish or dust speck on the tape but yet gives an ability to follow tracks on the tape which are closely packed. The guide means and the heads are disposed so that when the tape is transported across the heads, the heads follow paths which are parallel to the edges of the tape and each head is in contact with a position of the tape spaced apart in the direction of movement of the tape. In one embodiment, the heads are horizontally disposed and the tape is guided over the heads at an acute angle to the horizontal. In another embodiment, the heads form part of an annulus and the tape is wound helically round a support drum.
    Type: Grant
    Filed: March 22, 1978
    Date of Patent: April 22, 1980
    Assignee: Independent Broadcasting Authority
    Inventor: John L. E. Baldwin
  • Patent number: 4152695
    Abstract: A magnetic recording disc includes a plurality of sectors, each of which includes a plurality of data tracks and a reference zone containing information for identifying the data tracks. Some of the sectors are standby sectors containing information which would normally be contained in the sectors containing the data tracks. The reference zones of all sectors contain binary fault indicating bits which indicate whether a particular sector contains faults, and parity bits having values dependent on the location of the parity bit and the value of the fault bit at the same location as the parity bit. A data processor commands a read out head for the disc to be located at a particular position. From the command position of the data processor and the value of the fault bit, the data processor computes an expected parity bit value. The expected parity bit value is compared with the parity bit value read from the disc to provide an indication as to whether the fault bit is accurate.
    Type: Grant
    Filed: September 21, 1977
    Date of Patent: May 1, 1979
    Assignee: Compagnie Internationale Pour l'Informatique
    Inventors: Gerard Democrate, Claude Cardot, Jacques Droux, Andre Oisel
  • Patent number: 4023203
    Abstract: This invention discloses a multi-track recorded information regenerating system which regenerates signals recorded on a plurality of tracks and which composes and demodulates these recorded signals so as to obtain a read output signal. The characteristic feature of the present invention is to provide a delay circuit, which delays the regenerated signals in each track. Three signals are synthesized; that is, a first signal is synthesized from two regenerated signals from two tracks, and a second and a third signal are synthesized from one of the regenerated signals from two tracks and one of the outputs of the delay circuit. These synthesized signals are detected by an error checking circuit to determine whether or not said synthesized signals represent correct information recorded on the magnetic track, and the synthesized signal having the correct information is used as the read output of the multi-track recording system.
    Type: Grant
    Filed: November 26, 1975
    Date of Patent: May 10, 1977
    Assignee: Fujitsu Ltd.
    Inventors: Masaru Baba, Shuhei Inamori
  • Patent number: 4016547
    Abstract: Loss of a magnetic track on a rotating drum memory is compensated for by a erially connected shift register. Since replacement of an entire magnetic drum is a costly venture, it usually is not warranted when only one or two or several tracks have become corroded or otherwise scored. The shift register is provided with an appropriate amount of stages to handle the data otherwise stored on a damaged magnetic drum track. Provision is made in the inventive concept herein disclosed for providing index and clock signals in event of the failure of the index and clocking tracks in the memory drum.
    Type: Grant
    Filed: January 22, 1976
    Date of Patent: April 5, 1977
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventor: Robert E. Page
  • Patent number: 3972027
    Abstract: In an electronic computer, a magnetic card is recorded along two tracks for storing information. The relative delay between the sequential records on the tracks is controlled by two reference bits simultaneously written on the tracks of the card. During the reading, the first sensed reference bit starts a count which is stopped upon sensing the second reference bit. All data bits following the anticipated bits are transferred to the internal memory only after a delay proportional to the count.
    Type: Grant
    Filed: December 6, 1974
    Date of Patent: July 27, 1976
    Assignee: Ing. C. Olivetti & C., S.p.A.
    Inventor: Gastone Garziera