GB2217096B - Magnetic record medium and method of recording and reproducing security information on and from it - Google Patents

Magnetic record medium and method of recording and reproducing security information on and from it

Info

Publication number
GB2217096B
GB2217096B GB8906646A GB8906646A GB2217096B GB 2217096 B GB2217096 B GB 2217096B GB 8906646 A GB8906646 A GB 8906646A GB 8906646 A GB8906646 A GB 8906646A GB 2217096 B GB2217096 B GB 2217096B
Authority
GB
United Kingdom
Prior art keywords
recording
security information
record medium
magnetic record
reproducing
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
GB8906646A
Other versions
GB2217096A (en
GB8906646D0 (en
Inventor
Minoru Fujita
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Kyodo Printing Co Ltd
Original Assignee
Kyodo Printing Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Kyodo Printing Co Ltd filed Critical Kyodo Printing Co Ltd
Publication of GB8906646D0 publication Critical patent/GB8906646D0/en
Publication of GB2217096A publication Critical patent/GB2217096A/en
Application granted granted Critical
Publication of GB2217096B publication Critical patent/GB2217096B/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/02—Recording, reproducing, or erasing methods; Read, write or erase circuits therefor
    • G11B5/09—Digital recording
    • G—PHYSICS
    • G07—CHECKING-DEVICES
    • G07F—COIN-FREED OR LIKE APPARATUS
    • G07F7/00—Mechanisms actuated by objects other than coins to free or to actuate vending, hiring, coin or paper currency dispensing or refunding apparatus
    • G07F7/08—Mechanisms actuated by objects other than coins to free or to actuate vending, hiring, coin or paper currency dispensing or refunding apparatus by coded identity card or credit card or other personal identification means
    • G07F7/086—Mechanisms actuated by objects other than coins to free or to actuate vending, hiring, coin or paper currency dispensing or refunding apparatus by coded identity card or credit card or other personal identification means by passive credit-cards adapted therefor, e.g. constructive particularities to avoid counterfeiting, e.g. by inclusion of a physical or chemical security-layer
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
    • G06K7/00—Methods or arrangements for sensing record carriers, e.g. for reading patterns
    • G06K7/08—Methods or arrangements for sensing record carriers, e.g. for reading patterns by means detecting the change of an electrostatic or magnetic field, e.g. by detecting change of capacitance between electrodes
    • G06K7/082—Methods or arrangements for sensing record carriers, e.g. for reading patterns by means detecting the change of an electrostatic or magnetic field, e.g. by detecting change of capacitance between electrodes using inductive or magnetic sensors
    • G06K7/083—Methods or arrangements for sensing record carriers, e.g. for reading patterns by means detecting the change of an electrostatic or magnetic field, e.g. by detecting change of capacitance between electrodes using inductive or magnetic sensors inductive
    • G06K7/084—Methods or arrangements for sensing record carriers, e.g. for reading patterns by means detecting the change of an electrostatic or magnetic field, e.g. by detecting change of capacitance between electrodes using inductive or magnetic sensors inductive sensing magnetic material by relative movement detecting flux changes without altering its magnetised state
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
    • G11B20/10—Digital recording or reproducing
    • G11B20/14—Digital recording or reproducing using self-clocking codes
    • G11B20/1403—Digital recording or reproducing using self-clocking codes characterised by the use of two levels
    • G11B20/1407—Digital recording or reproducing using self-clocking codes characterised by the use of two levels code representation depending on a single bit, i.e. where a one is always represented by a first code symbol while a zero is always represented by a second code symbol
    • G11B20/1419—Digital recording or reproducing using self-clocking codes characterised by the use of two levels code representation depending on a single bit, i.e. where a one is always represented by a first code symbol while a zero is always represented by a second code symbol to or from biphase level coding, i.e. to or from codes where a one is coded as a transition from a high to a low level during the middle of a bit cell and a zero is encoded as a transition from a low to a high level during the middle of a bit cell or vice versa, e.g. split phase code, Manchester code conversion to or from biphase space or mark coding, i.e. to or from codes where there is a transition at the beginning of every bit cell and a one has no second transition and a zero has a second transition one half of a bit period later or vice versa, e.g. double frequency code, FM code
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
    • G11B20/10—Digital recording or reproducing
    • G11B20/14—Digital recording or reproducing using self-clocking codes
    • G11B20/1403—Digital recording or reproducing using self-clocking codes characterised by the use of two levels
    • G11B20/1423—Code representation depending on subsequent bits, e.g. delay modulation, double density code, Miller code

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Computer Security & Cryptography (AREA)
  • Artificial Intelligence (AREA)
  • Computer Vision & Pattern Recognition (AREA)
  • Theoretical Computer Science (AREA)
  • Signal Processing For Digital Recording And Reproducing (AREA)
  • Digital Magnetic Recording (AREA)
  • Recording Or Reproducing By Magnetic Means (AREA)
GB8906646A 1988-03-30 1989-03-22 Magnetic record medium and method of recording and reproducing security information on and from it Expired - Lifetime GB2217096B (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP63074675A JPH01248301A (en) 1988-03-30 1988-03-30 Method for recording and reproducing magnetic recording medium and its security information

Publications (3)

Publication Number Publication Date
GB8906646D0 GB8906646D0 (en) 1989-05-04
GB2217096A GB2217096A (en) 1989-10-18
GB2217096B true GB2217096B (en) 1992-01-22

Family

ID=13554041

Family Applications (1)

Application Number Title Priority Date Filing Date
GB8906646A Expired - Lifetime GB2217096B (en) 1988-03-30 1989-03-22 Magnetic record medium and method of recording and reproducing security information on and from it

Country Status (6)

Country Link
JP (1) JPH01248301A (en)
KR (1) KR930001701B1 (en)
AU (1) AU616490B2 (en)
GB (1) GB2217096B (en)
HK (1) HK106993A (en)
SG (1) SG27393G (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2367182B (en) * 2000-09-20 2004-05-26 Hewlett Packard Co Improvements in and relating to data protection

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4219851A (en) * 1978-11-24 1980-08-26 Honeywell Information Systems Inc. Group coded recording data recovery system
US4342054A (en) * 1979-06-06 1982-07-27 Nakamichi Corporation Information read device

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5942617A (en) * 1982-08-31 1984-03-09 Sansui Electric Co Magnetic recording and reproducing system
JPS5960713A (en) * 1982-09-30 1984-04-06 Sansui Electric Co Magnetic recording and reproducing system

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4219851A (en) * 1978-11-24 1980-08-26 Honeywell Information Systems Inc. Group coded recording data recovery system
US4342054A (en) * 1979-06-06 1982-07-27 Nakamichi Corporation Information read device

Also Published As

Publication number Publication date
KR890015243A (en) 1989-10-28
GB2217096A (en) 1989-10-18
SG27393G (en) 1993-05-21
KR930001701B1 (en) 1993-03-11
HK106993A (en) 1993-10-22
AU616490B2 (en) 1991-10-31
JPH01248301A (en) 1989-10-03
GB8906646D0 (en) 1989-05-04
AU3164689A (en) 1989-10-05

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Legal Events

Date Code Title Description
PCNP Patent ceased through non-payment of renewal fee

Effective date: 20040322