Patent EP0385498A2 successfully refreshed from Google Patents.
EP0385498A2
Expired / Lapsed
EP
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Recording and reproducing apparatus for optical disk
Assignee: Sony Corp
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Filing: 1990-03-02
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Granted: —
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Expires: 2010-03-02
Abstract
Abstract The present invention relates to an optical recording and reproducing apparatus comprising an erroneous recording prevention means which prevents this apparatus from making an erroneous recording or erasing operation while it records data on a writable disk (1). The apparatus is arranged such that, while it is performing a recording or erasing operation, a state of its beam of light just about to go off the control point of tracking and a state of its beam of light just about to go off the control point of focusing are each monitored and, when either of the states is detected, the recording or erasing operation is canceled. Hence, laser power of the beam of light can be controlled before the beam of light completely goes off the control point of tracking, thereby preventing the beam of light from affecting data having been recorded along other tracks.
Inventors
- 👤 Hiroyuki Shinkai
- 👤 Shigeaki Wachi
- 👤 Susumu Tosaka
- 👤 Sumihiro Okawa
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 22:44
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/08; G11B7/09; G11B7/0946; G11B19/00; G11B19/02; G11B19/04; G11B27/00; G11B27/36; G11B7/004; G11B7/12; G11B7/125
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
139 words
An optical recording and reproducing apparatus capable of recording and erasing data on a writable optical disk comprising: focus servo means (7) having focus error detection means and using its output for focus servo control of a beam of light; tracking servo means (6) having tracking error detection means and using its output for tracking servo control of the beam of light; detrack detection means (10T) for detecting a state of the level of said tracking error signal having gone outside a predetermined range; defocus detection means (10F) for detecting a state of the level of said focus error signal having gone outside a predetermined range; and control means (9), while said apparatus is in a mode of recording or erasing data, for cancelling said recording or erasing mode when either of said detrack or defocus state is detected.
Claim 2
Dependent Claim
139 words
An optical recording and reproducing apparatus capable of recording and erasing data on a writable optical disk comprising: focus servo means (7) having focus error detection means and using its output for focus servo control of a beam of light; tracking servo means (6) having tracking error detection means and using its output for tracking servo control of the beam of light; detrack detection means (10T) for detecting a state of the level of said tracking error signal having gone outside a predetermined range; defocus detection means (10F) for detecting a state of the level of said focus error signal having gone outside a predetermined range; and control means (9), while said apparatus is in a mode of recording or erasing data, for cancelling said recording or erasing mode when either of said detrack or defocus state is detected.
Claim 3
Dependent Claim
40 words
An optical recording and reproducing apparatus according to claim 1, wherein said detrack detection means (10T) detects a detrack state by comparing said tracking error signal with a positive and a negative reference level smaller than a maximum error signal.
Claim 4
Dependent Claim
42 words
An optical recording and reproducing apparatus according to claim 1 or 2, wherein said defocus detection means (10T) detects a defocus state by comparing said focus error signal with a positive and a negative reference level smaller than a maximum error signal.
Claim 5
Dependent Claim
55 words
An optical recording and reproducing apparatus according to anyone of claims 1 to 3, wherein said apparatus further comprises drive control means which, while said apparatus is in a mode of recording or erasing data, changes the mode to a mode capable of reproducing data when either of said detrack and defocus states is detected.
Claim 6
Dependent Claim
23 words
An optical recording and reproducing apparatus according to claim 4, wherein said drive control means controls laser power of said beam of light.
Claim 7
Dependent Claim
79 words
An optical recording and reproducing apparatus according to claim 4 or 5, wherein said apparatus further comprises address monitor means for detecting that the mode has been changed by said drive control means to the mode capable of reproducing data and, thereupon, detecting an address signal recorded on said disk; and means for detecting that said address signal is normally obtained by said address monitor means and, thereupon, resetting the mode to the mode capable of recording or erasing.
References Cited (Backward Citations)
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