GB1439213A - Method of making magnetic recordings which cannot be altered without it being noticed and magnetic recording media - Google Patents

Method of making magnetic recordings which cannot be altered without it being noticed and magnetic recording media

Info

Publication number
GB1439213A
GB1439213A GB4857073A GB4857073A GB1439213A GB 1439213 A GB1439213 A GB 1439213A GB 4857073 A GB4857073 A GB 4857073A GB 4857073 A GB4857073 A GB 4857073A GB 1439213 A GB1439213 A GB 1439213A
Authority
GB
United Kingdom
Prior art keywords
medium
temperature
recording
magnetic
antiferromagnetic
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
Application number
GB4857073A
Other languages
English (en)
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.)
BASF SE
Original Assignee
BASF SE
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 BASF SE filed Critical BASF SE
Publication of GB1439213A publication Critical patent/GB1439213A/en
Expired legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B23/00—Record carriers not specific to the method of recording or reproducing; Accessories, e.g. containers, specially adapted for co-operation with the recording or reproducing apparatus ; Intermediate mediums; Apparatus or processes specially adapted for their manufacture
    • G11B23/28—Indicating or preventing prior or unauthorised use, e.g. cassettes with sealing or locking means, write-protect devices for discs
    • G11B23/281—Indicating or preventing prior or unauthorised use, e.g. cassettes with sealing or locking means, write-protect devices for discs by changing the physical properties of the record carrier
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G5/00—Recording members for original recording by exposure, e.g. to light, to heat, to electrons; Manufacture thereof; Selection of materials therefor
    • G03G5/16—Layers for recording by changing the magnetic properties, e.g. for Curie-point-writing
    • 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
    • G11B5/62—Record carriers characterised by the selection of the material
    • G11B5/64—Record carriers characterised by the selection of the material comprising only the magnetic material without bonding agent
    • 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
    • G11B5/62—Record carriers characterised by the selection of the material
    • G11B5/68—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent
    • G11B5/70—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer
    • 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
    • G11B5/62—Record carriers characterised by the selection of the material
    • G11B5/68—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent
    • G11B5/70—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer
    • G11B5/706—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer characterised by the composition of the magnetic material

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Security & Cryptography (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Paints Or Removers (AREA)
  • Magnetic Record Carriers (AREA)
  • Manufacturing Of Magnetic Record Carriers (AREA)
  • Recording Or Reproducing By Magnetic Means (AREA)
GB4857073A 1972-10-20 1973-10-18 Method of making magnetic recordings which cannot be altered without it being noticed and magnetic recording media Expired GB1439213A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
AT898672A AT343373B (de) 1972-10-20 1972-10-20 Magnetogrammtrager zur nicht unbemerkt veranderbaren aufzeichnung magnetischer signale und verfahren zur herstellung solcher aufzeichnungen

Publications (1)

Publication Number Publication Date
GB1439213A true GB1439213A (en) 1976-06-16

Family

ID=3610215

Family Applications (1)

Application Number Title Priority Date Filing Date
GB4857073A Expired GB1439213A (en) 1972-10-20 1973-10-18 Method of making magnetic recordings which cannot be altered without it being noticed and magnetic recording media

Country Status (9)

Country Link
US (1) US3883892A (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)
JP (1) JPS576163B2 (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)
AT (1) AT343373B (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)
BE (1) BE806345A (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)
CA (1) CA1003954A (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)
DE (1) DE2344644C2 (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)
FR (1) FR2204006B1 (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)
GB (1) GB1439213A (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)
IT (1) IT994466B (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)

Families Citing this family (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1524187A (en) * 1974-10-16 1978-09-06 Emi Ltd Magnetic recording
US4239959A (en) * 1977-03-23 1980-12-16 General Kinetics Incorporated Perpetuation of information in magnetically recorded medium
DE2950174A1 (de) * 1979-12-13 1981-06-19 Basf Ag, 6700 Ludwigshafen Verfahren und vorrichtung zur echtheitspruefung von aufzeichnungstraegern, die gegen faelschung zu sichern sind
DE2950129A1 (de) * 1979-12-13 1981-06-19 BASF Corp., New York, N.Y. Verfahren und vorrichtung zur echtheitspruefung von aufzeichnungstraegern, die gegen faelschung zu sichern sind
US4404603A (en) * 1980-05-27 1983-09-13 Warren Eugene D Apparatus and method for inspecting magnetic tape recorded material for alterations
EP0215023B1 (en) * 1985-03-18 1990-12-05 McWHIRTER HOLDINGS PTY LIMITED Magnetic tape cassette having a prerecorded low frequency tone
US4980782A (en) * 1985-06-03 1990-12-25 Peter Ginkel Software protection and identification system
US4858036A (en) * 1986-08-04 1989-08-15 Peter Ginkel Software protection and identification system
US4639584A (en) * 1985-07-25 1987-01-27 Adams Robert T Non-alterable magnetic coding
US4706282A (en) * 1985-12-23 1987-11-10 Minnesota Mining And Manufacturing Company Decoder for a recorder-decoder system
JPH04105458U (ja) * 1991-01-16 1992-09-10 日本電池株式会社 電池用液口栓部
US5533759A (en) * 1994-09-13 1996-07-09 Eastman Kodak Company Method of currency or document validation by use of a temperature sensitive magnetic pattern
JP2001076331A (ja) * 1999-09-02 2001-03-23 Toshiba Corp 磁気記録媒体及び磁気記録再生装置
DE10008097A1 (de) * 2000-02-22 2001-09-20 Forschungszentrum Juelich Gmbh Markierungseinrichtung sowie Verfahren zum Auslesen einer solchen Markierungseinrichtung
EP1662486A1 (en) * 2004-11-29 2006-05-31 EMPA Eidgenössische Materialprüfungs- und Forschungsanstalt Process for storing information in a magnetic multi-layer device

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3134094A (en) * 1963-07-02 1964-05-19 Litton Systems Inc Spin resonant transducer
US3648257A (en) * 1966-08-24 1972-03-07 Minnesota Mining & Mfg Sheetlike material, the method of storing an image consisting of differing magnetic, electrical, and optical properties
US3521294A (en) * 1967-03-13 1970-07-21 Ampex Magneto thermal recording process and apparatus
FR1524309A (fr) * 1967-03-29 1968-05-10 Centre Nat Rech Scient Mémoires d'informations binaires à structures magnétiques en couches minces

Also Published As

Publication number Publication date
FR2204006A1 (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html) 1974-05-17
CA1003954A (en) 1977-01-18
BE806345A (fr) 1974-04-22
AT343373B (de) 1978-05-26
IT994466B (it) 1975-10-20
ATA898672A (de) 1977-09-15
JPS4975116A (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html) 1974-07-19
DE2344644A1 (de) 1974-05-02
FR2204006B1 (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html) 1977-03-11
DE2344644C2 (de) 1982-04-15
US3883892A (en) 1975-05-13
JPS576163B2 (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html) 1982-02-03

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Legal Events

Date Code Title Description
PS Patent sealed [section 19, patents act 1949]
PE20 Patent expired after termination of 20 years

Effective date: 19931017