US4910724A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Information recording medium having an area for recording information indicating logical erasure of data and method for recording information
Assignee: Canon Inc
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Filing: 1989-06-27
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Granted: 1990-03-20
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Expires: 2009-06-27
Abstract
Abstract There is disclosed an information recording medium having an area for recording data and an area for recording a directory used to manage the recorded data, by providing an area for recording information indicating logical erasure of the unnecessary data. In the information record method of the present invention, when unnecessary data is produced, information indicating the logical erasure of the data is recorded in the area of the information record medium in which the directory is recorded.
Inventors
- 👤 Wataru Sakagami
- 👤 Yutaka Ogasawara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 07:15
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/007; G11B7/00745; G06; G06F; G06F16/00; G06F16/90; G06F16/901; G06F16/9017; G11B27/00; G11B27/10; G11B27/19; G11B27/28; G11B27/32; G11B27/327; G11B7/004; G06F2216/00; G06F2216/09
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
93 words
A method for recording information on an information recording medium comprising a first area for recording data and a second area for recording at least one directory used to manage the data, said method comprising the steps of: recording data on the first area of the medium; recording a first directory on the second area of the medium corresponding to the data on the first area; and recording a second directory in an unrecorded portion of the second area to indicate logical erasure of the data when the data is no longer needed.
Claim 2
Independent Claim
93 words
A method for recording information on an information recording medium comprising a first area for recording data and a second area for recording at least one directory used to manage the data, said method comprising the steps of: recording data on the first area of the medium; recording a first directory on the second area of the medium corresponding to the data on the first area; and recording a second directory in an unrecorded portion of the second area to indicate logical erasure of the data when the data is no longer needed.
Claim 3
Dependent Claim
28 words
A method according to claim 1, wherein one of the first and second directories has a mark to make the first and second directories distinct from each other.
Claim 4
Dependent Claim
13 words
A method according to claim 2, wherein the mark comprises a delete bit.
Claim 5
Dependent Claim
38 words
A method according to claim 3, wherein the first and second directories include address portions indicating the position of the data in the first area, and the delete bit is in the address portion of the one directory.
Claim 6
Dependent Claim
20 words
A method according to claim 1, wherein the first and second directories each include a file name for the data.
Claim 7
Dependent Claim
47 words
A method according to claim 1, wherein a plurality of two-ended tracks are formed parallel on the medium and wherein the data is recorded form one end of one of the plurality of tracks and the directory is recorded from the other end of the one track.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-03-19 | 1993-09-18 | 1994-03-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-03-19 | 1997-09-18 | 1998-03-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-03-19 | 2001-09-18 | 2002-03-20 | $7700.00 | Window Closed / Lapsed |