EP0551011A2
Expired / Lapsed
EP
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Recording error determination method and data recording apparatus
Assignee: Canon Inc
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Filing: 1992-12-31
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Granted: —
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Expires: 2012-12-31
Abstract
Abstract A light beam is applied to an information recording medium to record information. A light amount of the light beam reflected by the recording medium is detected simultaneously with the recording of information. A defect of the recording medium is detected by comparing the detected light amount with a reference value. When a degree of the detected defect exceeds a predetermined level, the information is rerecorded on another portion of the recording medium.
Inventors
- 👤 Takaaki C/O Canon Kabushiki Kaisha Ashinuma
- 👤 Masakuni C/O Canon Kabushiki Kaisha Yamamoto
- 👤 Takatoshi c/o Canon Kabushiki Kaisha Suzuki
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 07:07
CPC Classifications
G; G11; G11B; G11B20/00; G11B20/10; G11B20/12; G11B20/1217; G11B11/00; G11B11/10; G11B11/105; G11B11/10595; G11B20/18; G11B20/1816; G11B20/182; G11B20/1866; G11B20/1879; G11B27/00; G11B27/36; G11B2020/183; G11B2220/00; G11B2220/20; G11B2220/25; G11B2220/2525
Claims Analysis
Total Claims: 35
Claim 1
Independent Claim
55 words
An information recording method comprising the steps of: recording information by radiating a light beam onto an information recording medium; detecting a light amount of the light beam reflected by said medium simultaneously with recording of the information; and detecting a defect on said medium by comparing the detected light amount with a reference value.
Claim 2
Dependent Claim
31 words
A method according to claim 1, further comprising the step of re-recording the information on another portion of said medium when a degree of the detected defect exceeds a predetermined level.
Claim 3
Dependent Claim
98 words
A recording determination method comprising the steps of: adding a synchronous signal to recording data; recording the recording data added with the synchronous signal by scanning an optical recording medium with a first light beam; reading out the synchronous signal and the data by scanning said medium with a second light beam following the first light beam simultaneously with recording of the recording data; delaying the recording data; and detecting an error by adjusting a timing of the delayed recording data on the basis of the readout synchronous signal, and comparing the recording data with the readout data.
Claim 4
Dependent Claim
48 words
A method according to claim 3, further comprising the steps of: determining a synchronous signal error by comparing the readout synchronous signal with a predetermined pattern; and determining a recording error on the basis of a determination result of the synchronous signal and the number of detected errors.
Claim 5
Dependent Claim
62 words
A recording determination method comprising the steps of: recording data on a recording medium; reading out the recorded data from said medium simultaneously with recording; detecting an error of the readout data; detecting a defect on a portion where the data is recorded; and determining a recording error on the basis of both an error detection result and a defect detection result.
Claim 6
Dependent Claim
64 words
A method according to claim 5, wherein the determining step includes the steps of determining that no recording error occurs when both the error detection result and the defect detection result are not more than predetermined determination criterions, and determining that a recording error occurs when at least one of the error detection result and the defect detection result exceeds the predetermined determination criterions.
Claim 7
Dependent Claim
41 words
A method according to claim 6, wherein the data is added with a synchronous signal, and said method further comprises the step of determining a recording error by comparing the synchronous signal added to the readout data with a predetermined pattern.
Claim 8
Dependent Claim
61 words
An information recording apparatus comprising: recording means for recording information by radiating a light beam onto an information recording medium; means for detecting a light amount of the light beam reflected by said medium simultaneously with recording of the information; and defect detection means for detecting a defect on said medium by comparing the detected light amount with a reference value.
Claim 9
Dependent Claim
81 words
A magnetooptical information recording apparatus comprising: an optical head for radiating a light beam of a predetermined intensity on a magnetooptical recording medium; a magnetic head for applying a magnetic field modulated according to information to said medium; a photodetector for detecting a light amount of the light beam reflected by said medium simultaneously with recording of the information; and defect detection means for detecting a defect on said medium by comparing an output from said photodetector with a reference value.
Claim 10
Dependent Claim
94 words
A magnetooptical information recording apparatus comprising: an optical head for radiating a light beam modulated according to a recording signal onto a magnetooptical recording medium; a memory for storing the recording signal; a magnetic head for applying a magnetic field in a predetermined direction to said medium; a photodetector for detecting a light amount of the light beam reflected by said medium simultaneously with recording of information; and defect detection means for detecting a defect on said medium by comparing an output signal from said photodetector with the recording signal stored in said memory.
Claim 11
Independent Claim
45 words
An apparatus according to either of claims 8 or 10, further comprising a controller for, when a degree of the defect detected by said defect detection means exceeds a predetermined level, controlling said optical head to re-record the information on another portion of said medium.
Claim 12
Dependent Claim
43 words
An apparatus according to claim 10, wherein said defect detection means comprises a binarizing circuit for binarizing the output signal from said photodetector, and a comparator for comparing an output signal from said binarizing circuit with the recording signal stored in said memory.
Claim 13
Independent Claim
63 words
An apparatus according to either of claims 8 or 10, wherein said photodetector comprises a polarizing beam splitter for splitting the light beam reflected by said medium into two beams, first and second photosensors for respectively receiving the two beams split by said polarizing beam splitter, and a summing amplifier for detecting a sum signal of outputs from said first and second photosensors.
Claim 14
Dependent Claim
110 words
A data recording apparatus comprising: means for recording recording data added with a synchronous signal by scanning an optical recording medium with a first light beam; means for reading out the synchronous signal and the data by scanning said medium with a second light beam following the first light beam simultaneously with recording of the recording data; a delay and timing adjusting circuit for delaying the recording data, and outputting the delayed recording data at a timing on the basis of the readout synchronous signal; and an error detection circuit for detecting an error by comparing the data output from said delay and timing adjusting circuit with the readout data.
Claim 15
Dependent Claim
152 words
A magnetooptical data recording apparatus comprising: an optical head for scanning a magnetooptical recording medium with a first light beam, and a second light beam, which follows the first light beam, and has a lower intensity than the first light beam; a magnetic head for applying a magnetic field modulated according to recording data added with a synchronous signal to said medium; a photodetector for detecting the second light beam reflected by said medium; an arithmetic circuit for reading out the data and the synchronous signal from an output of said photodetector; a delay and timing adjusting circuit for delaying the recording data, and outputting the recording data at a timing based on the synchronous signal read out by said arithmetic circuit; and an error detection circuit for detecting an error by comparing the data output from said delay and timing adjusting circuit with the data read out by said arithmetic circuit.
Claim 16
Independent Claim
71 words
An apparatus according to either of claims 8 or 15, further comprising: a synchronous signal detection circuit for determining a synchronous signal error by comparing the synchronous signal read out by said arithmetic circuit with a predetermined pattern; and a determining circuit for determining a recording error on the basis of a determination result from said synchronous signal detection circuit and the number of errors detected by said error detection circuit.
Claim 17
Dependent Claim
70 words
A data recording apparatus comprising: means for recording data on a recording medium; means for reading out the recorded data from said medium simultaneously with recording; means for detecting an error of the readout data; means for detecting a defect of a portion where the data is recorded; and determining means for determining a recording error on the basis of both an error detection result and a defect detection result.
Claim 18
Dependent Claim
70 words
An apparatus according to claim 17, wherein the data is added with a synchronous signal, said apparatus further comprises synchronous signal detection means for determining a synchronous signal error by comparing the synchronous signal added to the readout data with a predetermined pattern, and said determining means determines a recording error on the basis of the synchronous signal error determination result, the error detection result, and the defect detection result.
Claim 19
Dependent Claim
96 words
A data recording apparatus comprising: means for recording data by scanning an optical recording medium with a first light beam; means for reading out the recorded data by scanning said medium with a second light beam following the first light beam; means for detecting an error of the readout data; defect detection means for detecting a defect of a portion where the data is recorded from the second light beam reflected by said medium; and determining means for determining a recording error on the basis of both an error detection result and a defect detection result.
Claim 20
Dependent Claim
92 words
A data recording apparatus comprising: means for recording data by scanning an optical recording medium with a light beam; means for reading out the recorded data simultaneously with recording by detecting the light beam reflected by said medium; means for detecting an error of the readout data; defect detection means for detecting a defect of a portion where the data is recorded from the light beam reflected by said medium; and determining means for determining a recording error on the basis of both an error detection result and a defect detection result.
Claim 21
Independent Claim
41 words
An apparatus according to either of claims 19 or 20, wherein said defect detection means detects a light amount of the light beam reflected by said medium, and detects as a defect a portion where the detected light amount abruptly changes.
Claim 22
Independent Claim
31 words
An apparatus according to either of claims 19 or 20, wherein said defect detection means detects as a defect a portion where a signal amplitude of the readout data is decreased.
Claim 23
Independent Claim
74 words
An apparatus according to either of claims 19 or 20, wherein the data is added with a synchronous signal, said apparatus further comprises synchronous signal detection means for determining a synchronous signal error by comparing the synchronous signal added to the readout data with a predetermined pattern, and said determining means determines a recording error on the basis of the synchronous signal error determination result, the error detection result, and the defect detection result.
Claim 24
Dependent Claim
159 words
A magnetooptical data recording apparatus comprising: an optical head for scanning a magnetooptical recording medium with a first light beam and a second light beam which follows the first light beam, and has a lower intensity than the first light beam; a magnetic head for applying a magnetic field modulated according to recording data to said medium; a photodetector for detecting the second light beam reflected by said medium; an arithmetic circuit for reading out data from an output from said photodetector; a delay circuit for delaying the recording data; an error detection circuit for detecting an error by comparing the data output from said delay circuit with the data read out by said arithmetic circuit; a defect detection circuit for detecting a defect of a portion of said medium where the data has been recorded; and a determining means for determining a recording error on the basis of both an error detection result and a defect detection result.
Claim 25
Independent Claim
78 words
An apparatus according to any one of claims 14, 15 or 24, wherein said photodetector comprises a polarizing beam splitter for splitting the second light beam reflected by said medium into two beams having orthogonal directions of polarization each other, and first and second photosensors for respectively receiving the two beams split by said polarizing beam splitter, and said arithmetic circuit comprises a differential amplifier for outputting a difference between output signals from said first and second photosensors.
Claim 26
Dependent Claim
39 words
An apparatus according to claim 25, wherein said defect detection circuit comprises an adder for adding the output signals from said first and second photosensors, and a comparator for comparing an output from said adder with a reference value.
Claim 27
Dependent Claim
46 words
An apparatus according to claim 26, wherein said defect detection circuit comprises an envelope detection circuit for detecting a signal amplitude of the data read out by said arithmetic circuit, and a comparator for comparing an output from said envelope detection circuit with a reference value.
Claim 28
Dependent Claim
71 words
An apparatus according to claim 26, wherein the data is added with a synchronous signal, said apparatus further comprises a synchronous signal detection circuit for determining a synchronous signal error by comparing the synchronous signal added to the readout data with a predetermined pattern, and said determining circuit determines a recording error on the basis of the synchronous signal error determination result, the error detection result, and the defect detection result.
Claim 29
Dependent Claim
136 words
A magnetooptical data recording apparatus comprising: an optical head for scanning a magnetooptical recording medium with a light beam; a magnetic head for applying a magnetic field modulated according to recording data to said medium; a photodetector for detecting the light beam reflected by said medium; an arithmetic circuit for reading out data from an output from said photodetector; a delay circit for delaying the recording data; an error detection circuit for detecting an error by comparing the data output from said delay circuit with the data read out by said arithmetic circuit; a defect detection circuit for detecting a defect of a portion of said medium where the data has been recorded; and a determining circuit for determining a recording error on the bass of both an error detection result and a defect detection result.
Claim 30
Independent Claim
67 words
An apparatus according to any one of claims 17, 20, 24 or 29, wherein said determining circuit determines that no recording error occurs when both the error detection result and the defect detection result are not more than predetermined determination criterions, and determines that a recording error occurs when at least one of the error detection result and the defect detection result exceeds the predetermined determination criterions.
Claim 31
Dependent Claim
72 words
An apparatus according to claim 30, wherein said photodetector comprises a polarizing beam splitter for splitting the second light beam reflected by said medium into two beams having orthogonal directions of polarization each other, and first and second photosensors for respectively receiving the two beams split by said polarizing beam splitter, and said arithmetic circuit comprises a differential amplifier for outputting a difference between output signals from said first and second photosensors.
Claim 32
Dependent Claim
39 words
An apparatus according to claim 31, wherein said defect detection circuit comprises an adder for adding the output signals from said first and second photosensors, and a comparator for comparing an output from said adder with a reference value.
Claim 33
Dependent Claim
46 words
An apparatus according to claim 34, wherein said defect detection circuit comprises an envelope detection circuit for detecting a signal amplitude of the data read out by said arithmetic circuit, and a comparator for comparing an output from said envelope detection circuit with a reference value.
Claim 34
Dependent Claim
71 words
An apparatus according to claim 29, wherein the data is added with a synchronous signal, said apparatus further comprises a synchronous signal detection circuit for determining a synchronous signal error by comparing the syncrhonous signal added to the readout data with a predetermined pattern, and said determining circuit determines a recording error on the basis of the synchronous signal error determination result, the error detection result, and the defect detection result.
Claim 35
Dependent Claim
26 words
Information recording apparatus comprising means for radiating a light beam onto a recording medium and for detecting errors by evaluating light reflected from the recording medium.
References Cited (Backward Citations)
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