EP0218243A2
Expired / Lapsed
EP
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Data recording and reproducing apparatus
Assignee: Panasonic Holdings Corp
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Filing: 1986-10-08
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Granted: —
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Expires: 2006-10-08
Abstract
Abstract An optical disc for recording, reproducing or erasing data is radiated with an erasing light beam (10) and a recording-reproducing light beam (9) sequentially to record or reproduce the data with the recording-reproducing light beam and erase the data with the erasing light beam. In rewriting the data, the erasing light beam is radiated in advance of the recording-reproducing light beam on a data section of the disc, and the old data is erased by temperature increase and annealing by the erasing light beam, while new data is recorded by temperature increase and quenching with the recording-reproducing light beam set to the recording light intensity. After recording the new data, the light intensity of the erasing light beam is gradually decreased and turned off. In rewriting the sector data, the erasing light beam is radiated on the data section in advance of the recording-reproducing light beam, and by the temperature increase and annealing with the erasing light beam, the old data is erased, while new data is recorded by temperature increase and quenching with the recording-reproducing light beam set to the recording light intensity. After recording the new data, the light intensity of the erasing light beam is turned off after being modulated for a predetermined time. By doing so, the process of the temperature and quenching is eliminated which otherwise might be required at the time of turning off the erasing light beam, thereby preventing occurrence of a recording trace and a defect of the recording medium by a thermal shock.
Inventors
- 👤 Isao Satoh
- 👤 Makoto Ichinose
- 👤 Yoshihisa Fukushima
- 👤 Yuzuru Kuroki
- 👤 Yuuji Takagi
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 04:12
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/12; G11B7/125; G11B7/126; G11B7/004; G11B7/006
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
111 words
A data recording and reproducing apparatus comprising means (1, 2) for radiating an erasing light beam (10) and a recording-reproducing light beam (9) sequentially on an optical disc to record and reproduce and erase data, means (3) for recording and reproducing data with said recording-reproducing light beam, means (4) for erasing the data with said erasing light beam, and means (5) for controlling the light intensity of said erasing light beam, said erasing means (4) radiating a data recording section of the disc with the erasing light beam and said erasing light beam intensity control means (5) turning off the intensity of said erasing light beam by gradually reducing the same.
Claim 2
Dependent Claim
111 words
A data recording and reproducing apparatus comprising means (1, 2) for radiating an erasing light beam (10) and a recording-reproducing light beam (9) sequentially on an optical disc to record and reproduce and erase data, means (3) for recording and reproducing data with said recording-reproducing light beam, means (4) for erasing the data with said erasing light beam, and means (5) for controlling the light intensity of said erasing light beam, said erasing means (4) radiating a data recording section of the disc with the erasing light beam and said erasing light beam intensity control means (5) turning off the intensity of said erasing light beam by gradually reducing the same.
Claim 3
Dependent Claim
51 words
A data recording and reproducing apparatus according Claim 1, wherein the erasing light beam is radiated in advance of the recording-reproducing light beam, and after the recording-reproducing light beam is changed from the recording state to reproducing state, the intensity of the erasing light beam is progressively reduced and turned off.
Claim 4
Dependent Claim
79 words
A data recording and reproducing apparatus according to Claim 1, wherein said erasing means (4) produces an erasing gate signal (102) followed by the recording-reproducing means (3) producing a write gate signal (101), and after said write gate signal is turned off, the intensity of the erasing light beam is controlled by being reduced gradually with time, so that after a predetermined period of time, said erasing gate signal is turned off thereby together with said erasing light beam.
Claim 5
Dependent Claim
79 words
A data recording and reproducing apparatus according to Claim 2, wherein said erasing means (4) produces an erasing gate signal (102) followed by the recording-reproducing means (3) producing a write gate signal (101), and after said write gate signal is turned off, the intensity of the erasing light beam is controlled by being reduced gradually with time, so that after a predetermined period of time, said erasing gate signal is turned off thereby together with said erasing light beam.
Claim 6
Dependent Claim
105 words
A data recording and reproducing apparatus comprising means (1, 2) for radiating an erasing light beam (10) and a recording-reproducing light beam (9) sequentially on an optical disc to record and reproduce and erase data, means (3) for recording and reproducing the data with said recording-reproducing light beam, means (4) for erasing the data with said erasing light beam, and means (15) for modulating said erasing light beam, wherein said erasing means (4) radiates a data recording section of the disc, and said erasing light beam modulating means (15) turns off while modulating the intensity of said erasing light beam with a high frequency signal.
Claim 7
Dependent Claim
105 words
A data recording and reproducing apparatus comprising means (1, 2) for radiating an erasing light beam (10) and a recording-reproducing light beam (9) sequentially on an optical disc to record and reproduce and erase data, means (3) for recording and reproducing the data with said recording-reproducing light beam, means (4) for erasing the data with said erasing light beam, and means (15) for modulating said erasing light beam, wherein said erasing means (4) radiates a data recording section of the disc, and said erasing light beam modulating means (15) turns off while modulating the intensity of said erasing light beam with a high frequency signal.
Claim 8
Dependent Claim
58 words
A data recording and reproducing apparatus according to Claim 5, wherein said erasing light beam is radiated in advance of said recording-reproducing light beam, and after said recording-reproducing light beam is changed from the recording state into the reproducing state, the intensity of the erasing light beam is turned off while being modulated by a high frequency signal.
Claim 9
Dependent Claim
71 words
A data recording and reproducing apparatus according to Claim 5, wherein the erasing means (4) produces the erasing gate signal followed by said recording-reproducing means (3) producing the write gate signal, and after said write gate signal is turned off, the light intensity of said erasing light beam is modulated, so that after a predetermined period of time, the erasing gate signal is turned off together with said erasing light beam.
Claim 10
Dependent Claim
71 words
A data recording and reproducing apparatus according to Claim 6, wherein the erasing means (4) produces the erasing gate signal, followed by said recording-reproducing means (3) producing the write gate signal, and after said write gate signal is turned off, the light intensity of said erasing light beam is modulated, so that after a predetermined period of time, the erasing gate signal is turned off together with said erasing light beam.
Claim 11
Dependent Claim
38 words
A data recording and reproducing apparatus according to anyone of claims 1 to 4, wherein the output of said recording-reproducing light beam changes from the recording state into reproducing state by being pulse-modulated in said recording-reproducing means (3).
Claim 12
Dependent Claim
39 words
A data recording and reproducing apparatus according to anyone of claims 5 to 8, wherein the output of said recording- reproducing light beam changes from the recording state into reproducing state by being pulse-modulated in said recording-reproducing means (3).
References Cited (Backward Citations)
No citation records indexed.
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