GB1529566A - Magnetic recording - Google Patents
Magnetic recordingInfo
- Publication number
- GB1529566A GB1529566A GB4474774A GB4474774A GB1529566A GB 1529566 A GB1529566 A GB 1529566A GB 4474774 A GB4474774 A GB 4474774A GB 4474774 A GB4474774 A GB 4474774A GB 1529566 A GB1529566 A GB 1529566A
- Authority
- GB
- United Kingdom
- Prior art keywords
- tape
- watermarked
- magnetic
- oct
- detected
- 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
Links
- 239000002245 particle Substances 0.000 abstract 2
- 238000001514 detection method Methods 0.000 abstract 1
- 230000005415 magnetization Effects 0.000 abstract 1
- 238000004519 manufacturing process Methods 0.000 abstract 1
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
- G06—COMPUTING; CALCULATING OR COUNTING
- G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
- G06K1/00—Methods or arrangements for marking the record carrier in digital fashion
- G06K1/12—Methods or arrangements for marking the record carrier in digital fashion otherwise than by punching
- G06K1/125—Methods or arrangements for marking the record carrier in digital fashion otherwise than by punching by magnetic means
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
- G06K19/00—Record carriers for use with machines and with at least a part designed to carry digital markings
- G06K19/02—Record carriers for use with machines and with at least a part designed to carry digital markings characterised by the selection of materials, e.g. to avoid wear during transport through the machine
-
- 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
- G11B20/00086—Circuits for prevention of unauthorised reproduction or copying, e.g. piracy
-
- 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
- G11B20/00086—Circuits for prevention of unauthorised reproduction or copying, e.g. piracy
- G11B20/00094—Circuits for prevention of unauthorised reproduction or copying, e.g. piracy involving measures which result in a restriction to authorised record carriers
- G11B20/00123—Circuits for prevention of unauthorised reproduction or copying, e.g. piracy involving measures which result in a restriction to authorised record carriers the record carrier being identified by recognising some of its unique characteristics, e.g. a unique defect pattern serving as a physical signature of the record carrier
-
- 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
- G11B23/30—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 with provision for auxiliary signals
- G11B23/36—Signals on record carriers or on containers and recorded by the same method as the main recording
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B27/00—Editing; Indexing; Addressing; Timing or synchronising; Monitoring; Measuring tape travel
- G11B27/10—Indexing; Addressing; Timing or synchronising; Measuring tape travel
- G11B27/19—Indexing; Addressing; Timing or synchronising; Measuring tape travel by using information detectable on the record carrier
- G11B27/28—Indexing; Addressing; Timing or synchronising; Measuring tape travel by using information detectable on the record carrier by using information signals recorded by the same method as the main recording
-
- 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
-
- 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
- G11B5/84—Processes or apparatus specially adapted for manufacturing record carriers
-
- 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
- G11B5/84—Processes or apparatus specially adapted for manufacturing record carriers
- G11B5/842—Coating a support with a liquid magnetic dispersion
- G11B5/845—Coating a support with a liquid magnetic dispersion in a magnetic field
Landscapes
- Engineering & Computer Science (AREA)
- Computer Security & Cryptography (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Theoretical Computer Science (AREA)
- Signal Processing (AREA)
- Chemical & Material Sciences (AREA)
- Dispersion Chemistry (AREA)
- Magnetic Record Carriers (AREA)
- Paints Or Removers (AREA)
- Manufacturing Of Magnetic Record Carriers (AREA)
Abstract
1529566 "Watermarked" magnetic tape EMI Ltd 2 Oct 1975 [16 Oct 1974 21 Jan 1975] 44747/74 and 2546/75 Heading G5R Magnetic tape in which the preferred axes of magnetization of the particles forming the magnetic layer are normally aligned in the direction of tape length, is "watermarked" during manufacture by altering the orientation of the preferred axes at positions along the length of the tape. The magnetic axis of the particles is changed through an angle of about 25 degrees only whereby the resultant change in remanence at these positions is sufficiently low not to interfere with the playback of a signal recorded on the tape yet is of sufficient level to be detected. Where the "watermarked" tape has a number of tracks one of these can be used for detection purposes only or where the tape is single track an information free part of the track can be magnetized with a unidirectional field so that the watermark signal can be detected.
Priority Applications (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB4474774A GB1529566A (en) | 1974-10-16 | 1974-10-16 | Magnetic recording |
DE19752545580 DE2545580A1 (en) | 1974-10-16 | 1975-10-11 | MAGNETIC RECORDING CARRIER, METHOD OF MANUFACTURING THEREOF, AND INFORMATION RECORDING SYSTEM |
FR7531358A FR2288369A1 (en) | 1974-10-16 | 1975-10-14 | MAGNETIC RECORDING |
NL7512181A NL7512181A (en) | 1974-10-16 | 1975-10-16 | MAGNETIC RECORDING MEDIUM AND METHOD FOR ITS MANUFACTURE. |
JP50124866A JPS5165605A (en) | 1974-10-16 | 1975-10-16 |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB4474774A GB1529566A (en) | 1974-10-16 | 1974-10-16 | Magnetic recording |
GB254675 | 1975-01-21 |
Publications (1)
Publication Number | Publication Date |
---|---|
GB1529566A true GB1529566A (en) | 1978-10-25 |
Family
ID=26237585
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB4474774A Expired GB1529566A (en) | 1974-10-16 | 1974-10-16 | Magnetic recording |
Country Status (5)
Country | Link |
---|---|
JP (1) | JPS5165605A (en) |
DE (1) | DE2545580A1 (en) |
FR (1) | FR2288369A1 (en) |
GB (1) | GB1529566A (en) |
NL (1) | NL7512181A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0067178A1 (en) * | 1980-12-16 | 1982-12-22 | Minnesota Mining Mfg Australia | Method and apparatus for verification of recorded messages. |
Families Citing this family (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4242400A (en) * | 1977-10-15 | 1980-12-30 | E M I Limited | Magnetically structured materials |
JPS5552564A (en) * | 1978-10-13 | 1980-04-17 | Sony Corp | Check unit for suitability of stuck label of tape cassette |
DE2922882A1 (en) * | 1979-06-06 | 1980-12-11 | Stockburger H | METHOD FOR SECURING CARTRIDGES AND THEIR LABELS AND / OR PACKAGING AGAINST IMITATION |
FR2515403A1 (en) * | 1981-10-28 | 1983-04-29 | Quadrivium Inf | METHOD FOR IDENTIFYING A SOUND RECORDING AND DUPLICATION INSTALLATION IMPLEMENTING THE METHOD |
FR2534433B1 (en) * | 1982-10-08 | 1986-04-11 | Thomson Csf | METHOD FOR PROTECTING A SEQUENCE OF VIDEO IMAGES AGAINST FRAUDULENT USE AND DEVICES FOR CARRYING OUT SAID METHOD |
DE3319343A1 (en) * | 1982-11-08 | 1984-05-10 | Vault Corp | METHOD AND DEVICE FOR THE IMPOSSIBILITY OF UNAUTHORIZED COPIES OF RECORDED DATA |
DE3375854D1 (en) * | 1982-11-22 | 1988-04-07 | Dysan Corp | Method and apparatus for authenticating memory disk |
AT378620B (en) * | 1983-08-11 | 1985-09-10 | Heinz Seidl | MAGNETOGRAM CARRIER WHOSE ORIGIN IS NON-REMARKABLY MARKED |
JPH0512068Y2 (en) * | 1985-02-27 | 1993-03-26 | ||
JPH0512067Y2 (en) * | 1985-02-27 | 1993-03-26 | ||
JPS62502297A (en) * | 1985-03-18 | 1987-09-03 | ミネソタ マイニング アンド マニユフアクチユアリング コンパニ− | Magnetic tape cassette with prerecorded infrasound |
JP2569294Y2 (en) * | 1991-01-25 | 1998-04-22 | 日産自動車株式会社 | Striatum protector |
-
1974
- 1974-10-16 GB GB4474774A patent/GB1529566A/en not_active Expired
-
1975
- 1975-10-11 DE DE19752545580 patent/DE2545580A1/en active Pending
- 1975-10-14 FR FR7531358A patent/FR2288369A1/en not_active Withdrawn
- 1975-10-16 JP JP50124866A patent/JPS5165605A/ja active Pending
- 1975-10-16 NL NL7512181A patent/NL7512181A/en not_active Application Discontinuation
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0067178A1 (en) * | 1980-12-16 | 1982-12-22 | Minnesota Mining Mfg Australia | Method and apparatus for verification of recorded messages. |
EP0067178A4 (en) * | 1980-12-16 | 1983-02-09 | Minnesota Mining Mfg Australia | Method and apparatus for verification of recorded messages. |
Also Published As
Publication number | Publication date |
---|---|
NL7512181A (en) | 1976-04-21 |
JPS5165605A (en) | 1976-06-07 |
DE2545580A1 (en) | 1976-05-06 |
FR2288369A1 (en) | 1976-05-14 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
PS | Patent sealed | ||
746 | Register noted 'licences of right' (sect. 46/1977) | ||
732 | Registration of transactions, instruments or events in the register (sect. 32/1977) | ||
PE20 | Patent expired after termination of 20 years |
Effective date: 19951001 |