EP0256827A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Apparatus for recording and reproducing data into/from an optical disc
Assignee: Sony Corp
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Filing: 1987-08-10
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Granted: —
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Expires: 2007-08-10
Abstract
Abstract An apparatus for recording and reproducing data into/from an optical disc is provided. This apparatus comprises: an optical disc having an optical recording medium into and from which data can be written and erased; a laser diode (1) to write, erase, and read out data into and from the optical disc; and a power setting circuit (4A-C,5A-C,6A-C,7A-C,8A-C) for sampling and holding a detection output from a photo diode (2) to detect a light emission power of the laser diode (1), for comparing the value sampled and held with a target value, and for setting the power of the laser diode (1). The light emission power of the laser diode (1) in each of the data writing, erasing, and reading modes is controlled by the power setting means. A part of a recording area of the optical disc is provided with an extracting area (SA) to sample and hold the detection output from the photo diode (2).
Inventors
- 👤 Seiji Kobayashi
- 👤 Kiyoshi Ohsato
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 09:48
CPC Classifications
G; G11; G11B; G11B11/00; G11B11/10; G11B11/105; G11B11/10595; G11B11/10532; G11B11/10534; G11B11/10536; G11B11/10541; G11B11/10543; G11B11/1055; G11B11/10576; G11B11/10578; G11B7/00; G11B7/004; G11B7/12; G11B7/125; G11B7/126; G11B7/007; G11B7/00745
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
214 words
An apparatus for recording and reproducing data into/from an optical disc comprising: a detector (22, 23) for detecting the light emission power of said laser light source (1); power setting means (4A-C,5A-C,6A-C,7A-C,8A-C) for comparing the detected light emission power with a target value, and for setting the light emission power of the laser light source (1) on the basis of a comparison output; and drive means (10) for driving said laser light source (1) on the basis of the power set by said power setting means (4A-C,5A-C,6A-C,7A-C,8A-C); characterised in that, the optical disc being one in which a part of a recording area is provided with an extracting area (SA1, SA2) to sample and hold a detection output derived by detecting the light emission power of the laser light source (1), the power setting means (4A-C,5A-C,6A-C,7A-C,8A-C) is arranged to sample and hold the detection output from said detector (2,3), to compare said sampled and held value with a target value, and to set the light emission power of the laser light source (1) on the basis of a comparison output; and in that the light emission power of said laser light source (1) is controlled on the basis of the value sampled and held by said power setting means (4A-C,5A-C,6A-C,7A-C,8A-C) in said extracting area.
Claim 2
Independent Claim
214 words
An apparatus for recording and reproducing data into/from an optical disc comprising: a detector (22, 23) for detecting the light emission power of said laser light source (1); power setting means (4A-C,5A-C,6A-C,7A-C,8A-C) for comparing the detected light emission power with a target value, and for setting the light emission power of the laser light source (1) on the basis of a comparison output; and drive means (10) for driving said laser light source (1) on the basis of the power set by said power setting means (4A-C,5A-C,6A-C,7A-C,8A-C); characterised in that, the optical disc being one in which a part of a recording area is provided with an extracting area (SA1, SA2) to sample and hold a detection output derived by detecting the light emission power of the laser light source (1), the power setting means (4A-C,5A-C,6A-C,7A-C,8A-C) is arranged to sample and hold the detection output from said detector (2,3), to compare said sampled and held value with a target value, and to set the light emission power of the laser light source (1) on the basis of a comparison output; and in that the light emission power of said laser light source (1) is controlled on the basis of the value sampled and held by said power setting means (4A-C,5A-C,6A-C,7A-C,8A-C) in said extracting area.
Claim 3
Dependent Claim
190 words
An apparatus according to claim 1, wherein said power setting means (4A-C,5A-C,6A-C,7A-C,8A-C) comprises: recording power setting means (4A,5A,6A,7A) for setting the power of said laser light source (1) when data is recorded into said optical disc, said recording power setting means (4A,5A,6A,7A,8A) consisting of a first sample and hold circuit (4A) to sample and hold the detection output from said detector (2,3), a first comparator (5A) to compare an output of said first sample and hold circuit (4A) with a first target value, and a first filter (7A) which is supplied with a comparison output of said first comparator (5A); and reproducing power setting means (4C,5C,6C,7C) for setting the power of said laser light source (1) when the data recorded in the optical disc is reproduced, said recording power setting means (4C,5C,6C,7C) consisting of a second sample and hold circuit (4C) to sample and hold the detection output from the detector (2,3), a second comparator (5C) to compare an output of said second sample and hold circuit (4C) with a second target value, and a second filter (7C) which is supplied with a comparison output of said second comparator (5C).
Claim 4
Dependent Claim
104 words
An apparatus according to claim 2, wherein said power setting means (4A-C,5A-C,6A-C,7A-C,8A-C) has erasing power setting means (4B,5B,6B,7B,8B) for setting a power of said laser light source when the data recorded in the optical disc is erased, and said erasing power setting means (4B,5B,6B,7B,8B) consists of a third sample and hold circuit (4B) to sample and hold the detection output from said detector (2,3), a third comparator (5B) to compare and output of said third sample and hold circuit with a target value for erasing the data, and a third filter (7B) which is supplied with a comparison output of said third comparator (7B).
Claim 5
Dependent Claim
60 words
An apparatus according to claim 3, wherein said power setting means (4A-C,5A-C,6A-C,7A-C,8A-C) has switching means (9) for selectively switching the outputs of said recording power setting means (4A,5A,6A,7A,8A), said reproducing power setting means (4C,5C,6C,7C,8C), and said erasing power setting means (4B,5B,6B,7B,8B) in accordance with each of the recording, reproducing, and erasing modes and for supplying to said drive means (10).
Claim 6
Dependent Claim
67 words
An optical disc having an optical recording medium which consists of a plurality of tracks (T) and into which an information signal can be optically recorded, characterised in that a part (SA) of a recording area of said information signal is provided with an extracting area to set the light emission power of a laser light source to be used to record and reproduce said information signal.
Claim 7
Dependent Claim
67 words
An optical disc having an optical recording medium which consists of a plurality of tracks (T) and into which an information signal can be optically recorded, characterised in that a part (SA) of a recording area of said information signal is provided with an extracting area to set the light emission power of a laser light source to be used to record and reproduce said information signal.
Claim 8
Dependent Claim
38 words
An optical disc according to claim 5, wherein said recording area has a control area (SA1) in which a control signal for allowing an emission light from said laser light source to track said track (T) is recorded.
Claim 9
Dependent Claim
27 words
An optical disc according to claim 6, wherein said control area (SA1) is provided in said recording area on the upstream side (SA) of said extracting area.
Claim 10
Dependent Claim
71 words
An optical disc having an optical recording medium which consists of a plurality of tracks and into and from which an information signal can be optically recorded and erased, characterised in that a part of a recording area of said information signal is provided with an extracting area (SA) to set the light emission power of a laser light source to be used to record, erase, and reproduce said information signal.
Claim 11
Dependent Claim
71 words
An optical disc having an optical recording medium which consists of a plurality of tracks and into and from which an information signal can be optically recorded and erased, characterised in that a part of a recording area of said information signal is provided with an extracting area (SA) to set the light emission power of a laser light source to be used to record, erase, and reproduce said information signal.
Claim 12
Dependent Claim
38 words
An optical disc according to claim 8, wherein said recording area has a control area (SA1) in which a control signal for allowing an emission light from said laser light source to track said track (T) is recorded.
Claim 13
Dependent Claim
26 words
An optical disc according to claim 9, wherein said control area (SA1) is provided in said recording area on the upstream side of extracting area (SA).
References Cited (Backward Citations)
No citation records indexed.
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