EP0390601A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Information recording disk, and information record/reproducing method and apparatus utilizing the same
Assignee: Canon Inc
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Filing: 1990-03-30
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Granted: —
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Expires: 2010-03-30
Abstract
Abstract There is disclosed an information recording disk, and method and apparatus for information recording and reproduction, enabling secure tracking and full utilization of the recording capacity. For this purpose, the spiral or concentric track divided into plural sectors is provided with servo signals for detecting the tracking error, by an integral number per sector, and the number is made different between the tracks in the radially internal area of thc disk and those in the external area. The disk is rotated at a constant angular velocity, and the tracking error is detected by the servo signals with a first clock signal of a constant frequency, while the information recording and/or reproduction is conducted with a second clock signal of which frequency is higher for the tracks in the external area of the disk.
Inventors
- 👤 Shigeto Kanda
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 18:27
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/007; G11B7/00745; G11B20/00; G11B20/10; G11B20/12; G11B20/1217; G11B20/1258; G11B7/0079
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
81 words
An information recording disk comprising: tracks formed in plural turns in concentric or spiral manner on said disk, wherein each of said tracks is divided into plural sectors; and servo signals for detecting a tracking error, recorded in discrete manner in each of said sectors, wherein said servo signals are recorded in each sector by an integral number which is different between a track in the internal area of said disk and a track in the external area of said disk.
Claim 2
Dependent Claim
81 words
An information recording disk comprising: tracks formed in plural turns in concentric or spiral manner on said disk, wherein each of said tracks is divided into plural sectors; and servo signals for detecting a tracking error, recorded in discrete manner in each of said sectors, wherein said servo signals are recorded in each sector by an integral number which is different between a track in the internal area of said disk and a track in the external area of said disk.
Claim 3
Dependent Claim
36 words
An information recording disk according to claim 1, radially divided into plural zones each containing plural tracks, wherein the number of servo signals per sector is constant in a zone but is different between different zones.
Claim 4
Dependent Claim
42 words
An information recording disk according to claim 1, wherein each of said sectors is divided into blocks of a number same as that of the servo signals recorded in said sector, and a servo signal is recorded in each of said blocks.
Claim 5
Dependent Claim
34 words
An information recording disk according to claim 3, wherein an address signal is recorded in the first block in each of said sectors, with a bit rate same as that of said servo signal.
Claim 6
Dependent Claim
48 words
An information recording disk according to claim 1, wherein said servo signal consists of a clock pit formed in the center position of a track, and first and second wobble pits formed in the positions which are deviated from the center of said track in mutually opposite directions.
Claim 7
Dependent Claim
25 words
An information recording disk according to claim 1, wherein said disk is an optical disk capable of information recording/reproduction by irradiation with a light beam.
Claim 8
Dependent Claim
15 words
An information recording disk according to claim 6, wherein said disk is a photo-electro-magnetic disk.
Claim 9
Independent Claim
110 words
A method for information recording and/or reproduction to or from a disk, said disk having tracks of plural turns formed in concentric or spiral manner, and discretely recording therein servo signals for detecting a tracking error, comprising steps of: rotating said disk at a constant angular velocity; detecting the tracking error on the basis of said servo signals, utilizing a first reference clock signal of a constant frequency; and effecting the information recording and/or reproduction to or from a desired track, utilizing a second reference clock signal, of which frequency is so controlled as to be higher when said desired track is positioned in the outer side of the track.
Claim 10
Independent Claim
110 words
A method for information recording and/or reproduction to or from a disk, said disk having tracks of plural turns formed in concentric or spiral manner, and discretely recording therein servo signals for detecting a tracking error, comprising steps of: rotating said disk at a constant angular velocity; detecting the tracking error on the basis of said servo signals, utilizing a first reference clock signal of a constant frequency; and effecting the information recording and/or reproduction to or from a desired track, utilizing a second reference clock signal, of which frequency is so controlled as to be higher when said desired track is positioned in the outer side of the track.
Claim 11
Dependent Claim
46 words
A method according to claim 8, wherein said disk is radially divided into plural zones each containing plural tracks, and the frequence of said second reference clock signal is so controlled as to be constant within a zone but to be variable depending on the zone.
Claim 12
Dependent Claim
53 words
A method according to claim 9, wherein each of said tracks is circumferentially divided into plural blocks on the basis of said servo signals, and the number of bytes of the actually recorded data in each block is an integral number which is different according to the zone to which said block belongs.
Claim 13
Dependent Claim
38 words
A method according to claim 10, wherein the ratio of frequencies of said second reference clock signal in different zones is equal to the ratio of numbers of bytes of actually recorded data per block in said zones.
Claim 14
Dependent Claim
42 words
A method according to claim 10, wherein the number of channel bits of each of said servo signals is an integral multiple of the number of bytes of actual recorded data per block by the rate of said first reference clock signal.
Claim 15
Independent Claim
195 words
An apparatus for information recording and/or reproduction to or from a disk, said disk having tracks of plural turns formed in concentric or spiral manner, and discretely recording therein servo signals for detecting tracking error, comprising: a motor for rotating said disk at a constant angular velocity; a first clock generating circuit for generating a first reference clock signal of a constant frequency on the basis of the servo signals recorded on a desired track of said disk; a second clock generating circuit for generating a second reference clock signal from said first reference clock signal, said circuit being adapted to change the frequency of said second reference clock signal to be higher when said desired track is located in the outer side of said disk; an error detection circuit for detecting tracking error on the basis of the servo signal recorded on said desired track, utilizing said first reference clock signal; a head for effecting information recording and/or reproduction to or from said desired track, based on said second reference clock signal; and a control circuit for effecting the tracking control of said head, utilizing the tracking error detected by said error detection circuit.
Claim 16
Independent Claim
195 words
An apparatus for information recording and/or reproduction to or from a disk, said disk having tracks of plural turns formed in concentric or spiral manner, and discretely recording therein servo signals for detecting tracking error, comprising: a motor for rotating said disk at a constant angular velocity; a first clock generating circuit for generating a first reference clock signal of a constant frequency on the basis of the servo signals recorded on a desired track of said disk; a second clock generating circuit for generating a second reference clock signal from said first reference clock signal, said circuit being adapted to change the frequency of said second reference clock signal to be higher when said desired track is located in the outer side of said disk; an error detection circuit for detecting tracking error on the basis of the servo signal recorded on said desired track, utilizing said first reference clock signal; a head for effecting information recording and/or reproduction to or from said desired track, based on said second reference clock signal; and a control circuit for effecting the tracking control of said head, utilizing the tracking error detected by said error detection circuit.
Claim 17
Dependent Claim
71 words
An apparatus according to claim 13, wherein said first clock generating circuit is a phase-locked loop circuit composed of a voltage-controlled oscillator for generating a first reference clock signal, a frequency divider for dividing the frequency of the output of said oscillator, and a phase comparator for comparing the phase of the output of said frequency divider with that of the servo signal read by said head thereby controlling said oscillator.
Claim 18
Dependent Claim
92 words
An apparatus according to claim 13, wherein said second clock generating circuit is a phase-locked loop circuit composed of a voltage-controlled oscillator for generating a second reference clock signal, a first frequency divider with variable frequency dividing rate, for dividing the frequency of the output of said oscillator, a second frequency divider for dividing the frequency of said first reference clock signal, and a phase comparator for comparing the phase of the output of said first frequency divider with that of the output of said second frequency divider thereby controlling said oscillator.
Claim 19
Dependent Claim
34 words
An apparatus according to claim 13, wherein each of said tracks of said disk is circumferentially divided into plural sectors, and said second clock generating circuit is reset whenever said head passes each sector.
Claim 20
Dependent Claim
51 words
An apparatus according to claim 13, wherein said disk is radially divided into plural zones each containing plural tracks, and said second clock generating circuit is adapted to control the frequency of said second reference clock signal to be constant within each zone but to be variable depending on the zone.
Claim 21
Dependent Claim
27 words
An apparatus according to claim 13, wherein said head is an optical head for information recording and reproduction by irradiation of a light beam onto said disk.
References Cited (Backward Citations)
No citation records indexed.
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