US Patent No: 5,218,599
Number of patents in Portfolio can not be more than 2000
Method of recording and reproduction of information using a recording medium available for information overlap recording, a recording medium and a recording and reproducing apparatus using the method
Stats
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Jun 8, 1993
Issued date -
Sep 26, 1989
filing date -
07/412,474
serial no -
Expired
status
Importance
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Abstract
A recording medium is provided with a recording film having opto-magnetic characteristics formed on the substrate, with first information being recorded in advance in the form of pit strings of a phase structure. Second information is recorded over the first information through the application of a magnetic field with polarities corresponding to the second information in the presence of the irradiation of a high-power radiation beam, without damaging the record of the first information. The first and second information are produced independently and simultaneously with a single spot in the same area by use of different signal reproduction mechanisms for the first information and second information. The first information (ROM information) is reproduced as the variation in the amount (intensity) of the reflected light from the opto-magnetic recording film, and the second information (RAM information) is reproduced by detecting the rotational angle of the reflected light, based on the Kerr effect, from the opto-magnetic film concurrently with the reproduction of the first information using a single spot.
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First Claim
Related Publications
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International Classification(s)
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Cited Art
| Patent Info | (Count) | # Cites | Year |
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| 4,564,929 Information recording and reproducing apparatus with tracking control by sampling | 27 | 1982 | |
| 4,879,703 Magneto-optic memory apparatus with defect detection of recording medium during erasing operation | 19 | 1987 | |
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| 4,509,161 Optically readable information disc provided with a reflective optical structure | 14 | 1982 | |
| 4,868,373 Memory card comprising an optical memory disc and microelectronic memory component, and apparatus for transferring information to and from such card | 98 | 1986 | |
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| 4,905,215 System for reading information from two storage layers of an optical disk in different manners | 47 | 1987 | |
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| 4,736,352 Optical recording medium and apparatus for recording and reproducing data therein | 25 | 1984 | |
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| 4,817,075 Program selection for a digital audio disk | 34 | 1987 | |
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| 4,703,469 Optical data recording using radiation of different characteristics | 26 | 1985 | |
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| 4,750,152 Optical read/write device | 10 | 1986 | |
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| 4,733,385 Signal recording and reproducing apparatus for an opto-magnetic disk | 24 | 1986 | |
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| 4,940,618 Optical information recording medium | 55 | 1989 | |
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| 4,961,183 Optical disk arrangement with closed contours whose entire extent represents information | 3 | 1989 | |
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| 4,769,802 Information recording medium disc and method and apparatus for recording/reproducing information using the disc | 23 | 1985 | |