GB1517342A – Device for reading a record carrier
– Google Patents
GB1517342A – Device for reading a record carrier
– Google Patents
Device for reading a record carrier
Info
Publication number
GB1517342A
GB1517342A
GB19629/75A
GB1962975A
GB1517342A
GB 1517342 A
GB1517342 A
GB 1517342A
GB 19629/75 A
GB19629/75 A
GB 19629/75A
GB 1962975 A
GB1962975 A
GB 1962975A
GB 1517342 A
GB1517342 A
GB 1517342A
Authority
GB
United Kingdom
Prior art keywords
branch
output
frequency
reading
filter
Prior art date
1974-05-13
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
GB19629/75A
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.)
Philips Electronics UK Ltd
Original Assignee
Philips Electronic and Associated Industries 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.)
1974-05-13
Filing date
1975-05-09
Publication date
1978-07-12
1975-05-09
Application filed by Philips Electronic and Associated Industries Ltd
filed
Critical
Philips Electronic and Associated Industries Ltd
1978-07-12
Publication of GB1517342A
publication
Critical
patent/GB1517342A/en
Status
Expired
legal-status
Critical
Current
Links
Espacenet
Global Dossier
Discuss
Classifications
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
Abstract
1517342 Reading digital data PHILIPS ELECTRONIC & ASSOCIATED INDUSTRIES Ltd. 9 May 1975 [13 May 1974] 19629/75 Heading G4C Apparatus for reading self clocking digital data on a carrier includes a differentiating read member and resonant circuit REF2 (Fig. 3) connected to two branch lines, in the first of which is a device having a drooping amplitude/ frequency response curve and in the second of which is a filtering device having a rising amplitude/frequency response curve and a phase characteristic varying with frequency, the outputs of the branch lines being summed to form the output K2. As described the read head HD2 (Fig. 4) which has a coil L1 performing the differentiating function is connected via RC network and amplifier AMP 2 to the base electrode of a transistor Q1 which acts as the branching point, with the low frequency branch being taken from the collector. This branch includes a potentiometer PM (determining the transmission ratio between the branch lines) and capacitor CH forming the filter. The high frequency branch is connected to a bridged T type filter, the output K9 of which is connected via a noise filter C10, C11 and L4 to amplifier Q4 which together with the transistor Q3 in the low frequency branch has its connecter coupled to the output K6.
GB19629/75A
1974-05-13
1975-05-09
Device for reading a record carrier
Expired
GB1517342A
(en)
Applications Claiming Priority (1)
Application Number
Priority Date
Filing Date
Title
NL7406380A
NL7406380A
(en)
1974-05-13
1974-05-13
DEVICE FOR READING A MAGNETIZED INFORMATION CARRIER.
Publications (1)
Publication Number
Publication Date
GB1517342A
true
GB1517342A
(en)
1978-07-12
Family
ID=19821339
Family Applications (1)
Application Number
Title
Priority Date
Filing Date
GB19629/75A
Expired
GB1517342A
(en)
1974-05-13
1975-05-09
Device for reading a record carrier
Country Status (7)
Country
Link
US
(1)
US3996614A
(en)
JP
(1)
JPS552645B2
(en)
DE
(1)
DE2518983A1
(en)
FR
(1)
FR2271630A1
(en)
GB
(1)
GB1517342A
(en)
IT
(1)
IT1037991B
(en)
NL
(1)
NL7406380A
(en)
Families Citing this family (8)
* Cited by examiner, † Cited by third party
Publication number
Priority date
Publication date
Assignee
Title
JPS53125721A
(en)
*
1977-04-08
1978-11-02
Matsushita Electric Ind Co Ltd
Video receiver
US4244008A
(en)
*
1979-07-30
1981-01-06
Siemens Corporation
Read back compensation circuit for a magnetic recording device
US4323932A
(en)
*
1979-07-30
1982-04-06
Sperry Corporation
Readback pulse compensator
ZA81781B
(en)
*
1980-02-13
1982-03-31
Int Computers Ltd
Digital systems
EP0059559A1
(en)
*
1981-02-20
1982-09-08
Elcomatic Limited
Improvements in digital magnet recording
US4635140A
(en)
*
1982-05-08
1987-01-06
Victor Company Of Japan, Limited
Digital recording/playback system with limited frequency range
JPS628305A
(en)
*
1985-07-03
1987-01-16
Alps Electric Co Ltd
Magnetic recording and reproducing device
JPH0619808B2
(en)
*
1985-07-03
1994-03-16
アルプス電気株式会社
Magnetic recording / reproducing device
Family Cites Families (2)
* Cited by examiner, † Cited by third party
Publication number
Priority date
Publication date
Assignee
Title
US3711843A
(en)
*
1970-04-27
1973-01-16
Olivetti & Co Spa
Self-adapting synchronization system for reading information from a moving support
JPS5143367B2
(en)
*
1972-07-07
1976-11-20
1974
1974-05-13
NL
NL7406380A
patent/NL7406380A/en
not_active
Application Discontinuation
1975
1975-04-29
DE
DE19752518983
patent/DE2518983A1/en
not_active
Withdrawn
1975-05-07
US
US05/575,182
patent/US3996614A/en
not_active
Expired – Lifetime
1975-05-09
GB
GB19629/75A
patent/GB1517342A/en
not_active
Expired
1975-05-09
IT
IT23176/75A
patent/IT1037991B/en
active
1975-05-13
JP
JP5555275A
patent/JPS552645B2/ja
not_active
Expired
1975-05-13
FR
FR7514817A
patent/FR2271630A1/fr
not_active
Withdrawn
Also Published As
Publication number
Publication date
NL7406380A
(en)
1975-11-17
US3996614A
(en)
1976-12-07
DE2518983A1
(en)
1975-12-04
JPS50156410A
(en)
1975-12-17
FR2271630A1
(en)
1975-12-12
JPS552645B2
(en)
1980-01-21
IT1037991B
(en)
1979-11-20
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Legal Events
Date
Code
Title
Description
1978-11-08
PS
Patent sealed [section 19, patents act 1949]
1981-12-09
PCNP
Patent ceased through non-payment of renewal fee
