EP0371880A2
Expired / Lapsed
EP
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Method and apparatus for controlling and detecting recording laser beam
Assignee: Sony Corp
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Filing: 1989-11-29
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Granted: —
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Expires: 2009-11-29
Abstract
Abstract The present invention is concerned with control and detection of a laser beam for an optical disc recording/reproducing apparatus in which the intensity of a return laser beam reflected by an optical recording medium of a recording laser beam used for forming pits (P) and recording data on the recording medium during the recording mode is detected and an error signal including focusing and tracking error signals of the recording laser beam is formed on the basis of a detection output of the intensity of the return laser beam within a predetermined time interval (τ) before the pit (P) starts to be formed by the recording laser beam on the recording medium to control the recording laser beam, and in which, when recording data on the optical recording medium having sub-data previously recorded thereon as pre-grooves with wobbling, these sub-data are detected on the basis of the detection output of the return laser beam within said predetermined time interval (τ) or within a predetermined time interval other than said predetermined time interval (τ).
Inventors
- 👤 Hiroshi Ogawa
- 👤 Shinji Katsuramoto
- 👤 Masanobu Yamamoto
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 08:02
CPC Classifications
G; G11; G11B; G11B19/00; G11B19/02; G11B7/00; G11B7/12; G11B7/125; G11B7/126; G11B7/004; G11B7/0045; G11B7/08; G11B7/09
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
88 words
1) A method for controlling a recording laser beam comprising irradiating an optical recording medium with a recording laser beam during the record mode for forming pits and thereby recording data thereon, detecting the intensity of a return laser beam or the recording laser beam reflected from said recording medium, and controlling said recording laser beam on the basis of a detection output of the return laser light beam intensity within a predetermined time before actual pit formation on said optical recording medium by said recording laser beam.
Claim 2
Dependent Claim
88 words
1) A method for controlling a recording laser beam comprising irradiating an optical recording medium with a recording laser beam during the record mode for forming pits and thereby recording data thereon, detecting the intensity of a return laser beam or the recording laser beam reflected from said recording medium, and controlling said recording laser beam on the basis of a detection output of the return laser light beam intensity within a predetermined time before actual pit formation on said optical recording medium by said recording laser beam.
Claim 3
Dependent Claim
42 words
2) The method according to claim 1 wherein said recording laser beam is controlled by error signals including focusing and tracking error signals of said recording laser beam formed on the basis of the detection output of the return laser beam intensity.
Claim 4
Dependent Claim
93 words
3) An apparatus for controlling a recording laser beam comprising a laser light source for irradiating an optical recording medium with a recording laser beam for forming pits and thereby recording data thereon, detection means for detecting the intensity of a return laser beam or the recording laser beam reflected from said recording medium, and control means for controlling said recording laser beam on the basis of a detection output of return laser beam intensity within a predetermined time before actual pit formation on said optical recording medium by said recording laser beam.
Claim 5
Dependent Claim
93 words
3) An apparatus for controlling a recording laser beam comprising a laser light source for irradiating an optical recording medium with a recording laser beam for forming pits and thereby recording data thereon, detection means for detecting the intensity of a return laser beam or the recording laser beam reflected from said recording medium, and control means for controlling said recording laser beam on the basis of a detection output of return laser beam intensity within a predetermined time before actual pit formation on said optical recording medium by said recording laser beam.
Claim 6
Dependent Claim
44 words
4) The apparatus according to claim 3 further comprising servo means for forming error signals inclusive of focusing or tracking error signals of said recording laser beam on the basis of the detection output by said detection means for thereby controlling the recording beam.
Claim 7
Dependent Claim
37 words
5) The apparatus according to claim 3 wherein said servo means controls said recording laser beam on the basis of a sample-held output obtained by sample-holding said detection output by said detection means within said predetermined time.
Claim 8
Dependent Claim
37 words
6) The apparatus according to claim 4 wherein said servo means sample-holds said error signals formed on the basis of the detection output by said detection means within said predetermined time to control said recording laser beam.
Claim 9
Dependent Claim
39 words
7) The apparatus according to claim 4 wherein said servo means forms said error signals on the basis of a peak-hold output obtained by peak holding the detection output by said detection means to control said recording laser beam.
Claim 10
Dependent Claim
115 words
8) A method for detecting a recording laser beam comprising irradiating an optical recording medium with a recording laser beam for forming pits and recording data during the recording mode, said optical recording medium having sub-data previously recorded thereon as pre-grooves with wobbling, detecting a return laser beam or said recording laser beam reflected from said optical recording medium, and detecting said sub-data formed by said pre-grooves on the basis of a detection output of said return laser beam during a predetermined time interval before the pit starts to be formed on said optical recording medium by said recording laser beam or during the time the pit is being formed on said optical recording medium.
Claim 11
Dependent Claim
115 words
8) A method for detecting a recording laser beam comprising irradiating an optical recording medium with a recording laser beam for forming pits and recording data during the recording mode, said optical recording medium having sub-data previously recorded thereon as pre-grooves with wobbling, detecting a return laser beam or said recording laser beam reflected from said optical recording medium, and detecting said sub-data formed by said pre-grooves on the basis of a detection output of said return laser beam during a predetermined time interval before the pit starts to be formed on said optical recording medium by said recording laser beam or during the time the pit is being formed on said optical recording medium.
Claim 12
Dependent Claim
123 words
9) An apparatus for detecting a recording laser beam comprising a laser light source for irradiating an optical recording medium with a recording laser beam for forming pits and thereby recording data thereon, said recording medium having sub-data previously recorded thereon as pre-grooves with wobbling, detection means for detecting said return laser beam or said recording laser beam reflected by said optical recording medium, and sub-data detection means for detecting said sub-data formed by said pre-grooves on the basis of a detection output of said return laser beam during a predetermined time interval before the pit starts to be formed on said optical recordingmedium by said recording laser beam or during the time the pit is being formed on said optical recording medium.
Claim 13
Dependent Claim
123 words
9) An apparatus for detecting a recording laser beam comprising a laser light source for irradiating an optical recording medium with a recording laser beam for forming pits and thereby recording data thereon, said recording medium having sub-data previously recorded thereon as pre-grooves with wobbling, detection means for detecting said return laser beam or said recording laser beam reflected by said optical recording medium, and sub-data detection means for detecting said sub-data formed by said pre-grooves on the basis of a detection output of said return laser beam during a predetermined time interval before the pit starts to be formed on said optical recordingmedium by said recording laser beam or during the time the pit is being formed on said optical recording medium.
Claim 14
Dependent Claim
53 words
10) The apparatus according to claim 9 wherein said detection means has a pair of light receiving sections each of which is divided into at least two portions in a direction parallel to the tangential direction of said pre-grooves and differential outputs are obtained from each of said pair of light receiving sections.
Claim 15
Dependent Claim
101 words
11) The apparatus according to claim 11 wherein said sub-data reproducing means comprises filter means for taking out only the components based on the wobbling of said pre-grooves from the output of said detection means, sample-hold means for sample-holding the output of said filter means on the basis of sampling pulses produced during a predetermined time interval before the pit starts to be formed on said optical recording medium by said recording laser beam or during the time the pit is formed on said optical recording medium, and decoding means for reproducing the sub-data from the output of said sample-holding means.
Claim 16
Dependent Claim
141 words
12) A light output setting and controlling apparatus comprising a light source for writing data on an optical recording medium, photodetector means for detecting the volume of the light outputted from said light source and reflected by said optical recording medium, and controlling means for controlling the light output from said light source on the basis of a detection output by said detection means, said controlling means driving said light source with pulses to increase the light output of said light source gradually, said controlling means controlling the light output of said light source so that the reflected light of a predetermined light volume is detected by said detection means after the lapse of a predetermined time since the output timing of a light pulse by said light source until a recording pit starts to be formed on said recording medium.
Claim 17
Dependent Claim
141 words
12) A light output setting and controlling apparatus comprising a light source for writing data on an optical recording medium, photodetector means for detecting the volume of the light outputted from said light source and reflected by said optical recording medium, and controlling means for controlling the light output from said light source on the basis of a detection output by said detection means, said controlling means driving said light source with pulses to increase the light output of said light source gradually, said controlling means controlling the light output of said light source so that the reflected light of a predetermined light volume is detected by said detection means after the lapse of a predetermined time since the output timing of a light pulse by said light source until a recording pit starts to be formed on said recording medium.
Claim 18
Dependent Claim
48 words
13) The apparatus according to claim 12 wherein said light source is controlled by said controlling means on the basis of a first output from said photodetector means before said predetermined time elapses and a second output from said photodetector means after the lapse of said predetermined time.
Claim 19
Dependent Claim
66 words
14) The apparatus according to claim 13 wherein said controlling means computes the modulation factor of the light volume of the reflected light from said optical recording medium on the basis of said first and second outputs, compares the computed value of the modulation factor and the desired value of the modulation factor and controls said light source on the basis of the results of comparison.
Claim 20
Dependent Claim
67 words
15) The apparatus according to claim 14 wherein said controlling means computes the rate of change of the modulation factor of the light volume of the reflected light from said optical recording medium on the basis of the first and second outputs, compares the computed value and the desired value of the modulation factor and controls said light source on the basis of the results of comparison.
References Cited (Backward Citations)
No citation records indexed.
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