EP0325329A1
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EP
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Method of and apparatus for successively recording EFM-modulated signals
Assignee: Koninklijke Philips NV
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Filing: 1989-01-17
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Granted: —
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Expires: 2009-01-17
Abstract
Abstract A method of and apparatus for recording a first and a second EFM-modulated signal is described, which signals comprise EFM-subcode frames, the beginning of each EFM-subcode frame being marked by a subcode-synchronisation signal. In the track portion of a record carrier (1) intended for recording position-synchronisation signals are recorded by means of a track modulation which can be distinguished from the information pattern to be formed. During recording the subcode-synchronisation signals are maintained substantially in phase with the position-synchronisation signals (11), so that the track portions (14) in which the subcode-synchronisation signals are recorded substantially coincide with the track portions (140) in which the position-synchronisation signals are recorded. Recording of the first EFM-modulated signal (142) ends at a boundary position (144) which is situated at a predetermined position between the track portions (140) in which two successive position-synchronisation signals are recorded. Recording of the second EFM-modulated signal (143) begins substantially at the predetermined boundary position (144).
Inventors
- 👤 Wilhelmus Petrus Maria Raaijmakers
- 👤 Johannes Jan Mons
- 👤 Rudolf Roth
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 20:50
CPC Classifications
G; G11; G11B; G11B20/00; G11B20/10; G11B27/00; G11B27/02; G11B27/031; G11B27/034; G11B11/00; G11B11/10; G11B11/105; G11B11/10502; G11B11/10504; G11B11/1055; G11B11/10576; G11B11/10578; G11B27/10; G11B27/19; G11B27/28; G11B27/30; G11B27/3027; G11B27/3063; G11B7/00; G11B7/24; G11B7/2407; G11B7/24073; G11B7/24082; G11B2220/00; G11B2220/20; G11B2220/21; G11B2220/213; G11B2220/215; G11B2220/218; G11B2220/25; G11B2220/2537; G11B2220/2545
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
165 words
A method of successively recording a first and a second EFM-modulated signal at arbitrary intervals, which signals comprise EFM-subcode frames, the beginning of each EFM-subcode frame being indicated by a subcode-synchronisation signal, in which method an information pattern of recording marks is formed in a servo track of a record carrier of an inscribable type, which pattern is representative of the EFM-modulated signals, characterized in that said record carrier is of a type in which in the track portion intended for recording the information signals position-synchronisation signals are recorded as preformed track modulation which can be distinguished from the information pattern, the subcode-synchronisation signals being maintained substantially in phase with the prerecorded position-synchronisation signals during recording of the EFM-modulated signals, recording of the first EFM-modulated signal being terminated at a boundary position which is situated at a predetermined position between track portions in which two successive position-synchronisation signals have been recorded, and recording of the second information signal being started substantially at said boundary position.
Claim 2
Independent Claim
165 words
A method of successively recording a first and a second EFM-modulated signal at arbitrary intervals, which signals comprise EFM-subcode frames, the beginning of each EFM-subcode frame being indicated by a subcode-synchronisation signal, in which method an information pattern of recording marks is formed in a servo track of a record carrier of an inscribable type, which pattern is representative of the EFM-modulated signals, characterized in that said record carrier is of a type in which in the track portion intended for recording the information signals position-synchronisation signals are recorded as preformed track modulation which can be distinguished from the information pattern, the subcode-synchronisation signals being maintained substantially in phase with the prerecorded position-synchronisation signals during recording of the EFM-modulated signals, recording of the first EFM-modulated signal being terminated at a boundary position which is situated at a predetermined position between track portions in which two successive position-synchronisation signals have been recorded, and recording of the second information signal being started substantially at said boundary position.
Claim 3
Dependent Claim
30 words
A method as claimed in Claim 2, characterized in that the predetermined position procedes the centre of the track portion in which said two successively recorded position-synchronisation signals are situated.
Claim 4
Independent Claim
88 words
A method as claimed in any one of the Claims 1 or 2, characterized in that said record carrier is of a type in which position-code signals are recorded by means of the track modulation in track portions which are situated between the track portions used for recording the position-synchronisation signals, the position-code signals being indicative of the position of the track portion in which said position-code signals are recorded, in which method the boundary position is derived from the position-synchronisation signals and the position-code signals being read.
Claim 5
Dependent Claim
132 words
An apparatus for carrying out the method as claimed in Claim 1 or 3, which apparatus comprises a scanning device for scanning the servo track, which scanning device comprises write means for recording the EFM-modulated signals in the servo track being scanned, characterized in that the apparatus comprises means for reading the position-synchronisation signals by detection of the track modulation, means for maintaining the subcode-synchronisation signal in phase with the position-synchronisation signals during recording, means for detecting, on the basis of the position-synchronisation signals read, the instants at which said boundary position is scanned, means responsive to the detection of such an instant to terminate a recording being made, and means responsive to the detection of a later instant at which the boundary area is scanned again to start a subsequent recording.
Claim 6
Dependent Claim
49 words
An apparatus as claimed in Claim 4, characterized in that the detection means are adapted to generate a detection signal after a predetermined time interval after reading of the position-synchronisation signal recorded directly before the boundary position, which detection signal indicates the instant of scanning of the boundary position.
Claim 7
Dependent Claim
26 words
An apparatus as claimed in Claim 5, characterized in that the predetermined time interval is smaller than half the period of the position-synchronisation signals being read.
Claim 8
Independent Claim
60 words
An apparatus as claimed in any one of the Claims 4, 5 or 6, characterized in that the apparatus comprises means for detecting the instantaneous scanning position by reading the position-code signals, the detection means being adapted to select, depending on the detected scanning position, the position-synchronisation signal recorded immediately before the boundary position from the position-synchronisation signals being read.
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