Patent EP0299573A1 successfully refreshed from Google Patents.
EP0299573A1
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System for recording and/or reading an information signal, record carrier and recording and/or read apparatus for use in such a system, and method of and apparatus for manufacturing such a record carrier
Assignee: Koninklijke Philips NV
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Filing: 1988-07-08
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Granted: —
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Expires: 2008-07-08
Abstract
Abstract An optically readable record carrier (1) is revealed, which is provided with a track 4 comprising an information area in which an information signal (Vi) is or can be recorded. A position-information signal (Vp) which is synchronous with a clock signal is recorded in the track 4 by means of a track modulation (Fig. 3) corresponding to the position-information signal (Vp). The position-information signal (Vp) indicates the track portion in which the information signal is recorded. An apparatus for recording and/or reading the record carrier (1) comprises an optical system (53) for scanning the information area in the track (4) by means of a radiation beam (55), an optical detector (57) for detecting the radiation beam (55) reflected by the record carrier (1) and for generating a detection signal (Vd) which is representative of the modulation of the detected radiation beam (55) caused by the track modulation, and a detection circuit (60) for extracting the position-information signal (Vp) from the detection signal (Vd). The track modulation corresponding to the position-information signal (Vp) is situated at the location of the information area in such a way that its frequency spectrum (31) is situated substantially outside the frequency range (Be) occupied by the frequency spectrum (30) of the information signal (Vi). Further, an apparatus for manufacturing a record carrier (1) is described, in which a radiation-sensitive surface (85) is scanned by a radiation beam (87) in conformity with the desired track pattern. During scanning the radiation beam (87) is modulated in conformity with the position-information signal (Vp).
Inventors
- 👤 Johan Martien Rijnsburger
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-30 09:02
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/24; G11B7/26; G11B7/261; G11B27/00; G11B27/10; G11B27/19; G11B27/24; G11B27/28; G11B27/30; G11B27/3027; G11B7/2407; G11B7/24073; G11B7/24082; G11B2220/00; G11B2220/20; G11B2220/25; G11B2220/2537; G11B2220/2545
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
181 words
A system for recording and/or reading an information signal, which system comprises an optically readable record carrier provided with a track containing an information area in which the information signal is recorded or can be recorded, in which track a position-information signal which is synchronous with a clock signal is recorded by means of a track modulation corresponding to the position-information signal, and an apparatus for recording and/or reading the information signal, which apparatus comprises an optical system for scanning the information area with a radiation beam, an optical detector for detecting the radiation beam reflected by the information area and for generating a detection signal which is representative of the modulation of the radiation beam caused by the track modulation, and a detection circuit for extracting the position-information signal from the detection signal, characterized in that the track modulation corresponding to the position-information signal is situated at the location of the information area in such way that the frequency spectrum of the position-information signal is situated substantially outside the frequency range occupied by the frequency spectrum of the information signal.
Claim 2
Independent Claim
181 words
A system for recording and/or reading an information signal, which system comprises an optically readable record carrier provided with a track containing an information area in which the information signal is recorded or can be recorded, in which track a position-information signal which is synchronous with a clock signal is recorded by means of a track modulation corresponding to the position-information signal, and an apparatus for recording and/or reading the information signal, which apparatus comprises an optical system for scanning the information area with a radiation beam, an optical detector for detecting the radiation beam reflected by the information area and for generating a detection signal which is representative of the modulation of the radiation beam caused by the track modulation, and a detection circuit for extracting the position-information signal from the detection signal, characterized in that the track modulation corresponding to the position-information signal is situated at the location of the information area in such way that the frequency spectrum of the position-information signal is situated substantially outside the frequency range occupied by the frequency spectrum of the information signal.
Claim 3
Dependent Claim
48 words
A system as claimed in Claim 1, characterized in that for the purpose of extracting the position-information signal from the detection signal the detection circuit comprises a filter having a pass band which substantially corresponds to the frequency band occupied by the frequency spectrum of the position-information signal.
Claim 4
Dependent Claim
74 words
A system as claimed in Claim 1 or 2, characterized in that the recording and/or read apparatus comprises a clock-regeneration circuit for recovering the clock signal from the position-information signal and a control circuit for controlling the scanning velocity at a value for which the frequency of the clock signal is equal to a reference frequency, the frequency spectrum of the position-information signal being situated substantially outside the frequency band employed for velocity control.
Claim 5
Independent Claim
21 words
A system as claimed in any one of the preceding Claims, characterized in that the position-information signal exhibits a biphase modulation.
Claim 6
Independent Claim
24 words
A system as claimed in any one of the Claims 1 to 3, characterized in that the position-information signal exhibits a biphase mark modulation.
Claim 7
Independent Claim
35 words
A system as claimed in any one of the preceding Claims, characterized in that the track modulation is formed by a track undulation, the track excursion corresponding to the signal value of the position-information signal.
Claim 8
Dependent Claim
22 words
A recording and/or read apparatus for use in the system as claimed in any one of the Claims 1, 2 or 3.
Claim 9
Dependent Claim
22 words
A record carrier for use in the system as claimed in any one of the CLaims 1, 3, 4, 5 or 6.
Claim 10
Dependent Claim
83 words
A method of manufacturing a record carrier as claimed in Claim 8, a radiation-sensitive area being scanned by a radiation beam in accordance with a path corresponding to the desired track pattern, the radiation beam being modulated during scanning with a position-information signal which is in synchronism with a clock signal, the position-information signal indicating the instantaneous scanning position, characterized in that the frequency spectrum of the position -information signal is situated substantially outside the frequency range intended for recording the information signal.
Claim 11
Dependent Claim
30 words
A method as claimed in Claim 9, characterized in that the amplitudes of the frequency components of the position-information signal are substantially zero for fequencies below a predetermined frequency range.
Claim 12
Dependent Claim
17 words
A method as claimed in Claim 10, characterized in that the position-information signal exhibits a biphase modulation.
Claim 13
Dependent Claim
17 words
A method as claimed in Claim 11, characterized in that the position-information signal exhibits a biphase-mark modulation.
Claim 14
Independent Claim
51 words
A method as claimed in any one of the Claims 9, 10, 11 or 12, characterized in that for the purpose of modulating the radiation beam the beam is deflected in a direction perpendicular to the scanning direction over a distance which corresponds to the signal strength of the position-information signal.
Claim 15
Independent Claim
108 words
A device for carrying out a method as claimed in any one of the Claims 9, 10, 11, 12 or 13, comprising an optical system for scanning a radiation-sensitive surface with a radiation beam in conformity with the desired track pattern, means for generating a position-information signal which is in synchronism with a clock signal and which indicates the instantaneous scanning position, and means for modulating the radiation beam in conformity with the position-information signal during scanning, characterized in that the signal-generating means are adapted to generate a position-information signal having a frequency spectrum which is situated substantially outside the frequency range intended for recording the information signal.
Claim 16
Dependent Claim
31 words
An apparatus as claimed in Claim 14, characterized in that the signal-generating means are adapted to generate a position-information signal whose frequency components below a predetermined frequency are a substantially zero.
Claim 17
Dependent Claim
21 words
An apparatus as claimed in Claim 15, characterized in that the signal-generating means are adapted to generate a biphase-modulated position-information signal.
Claim 18
Dependent Claim
22 words
An apparatus as claimed in Claim 15, characterized in that the signal-generating means are adapted to generate a biphase-mark modulated position-information signal.
Claim 19
Independent Claim
54 words
An apparatus as claimed in any one of the Claims 14, 15, 16 or 17, characterized in that the apparatus comprises a deflection device for deflecting the scanning beam under control of the position-information signal in a direction perpendicular to the scanning direction over a distance corresponding to the strength of the position-information signal.
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EP0166199A1
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