US5541904A
Expired / Lapsed
US
⏱️ 0.0 years remaining
CD-ROM with machine-readable I.D. code
Assignee: Sony Corp
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Filing: 1995-06-02
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Granted: 1996-07-30
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Expires: 2015-06-02
Abstract
Abstract A machine-readable serial number is formed on a CD-ROM by using a laser to selectively remove a reflective layer from the CD-ROM. Removal of the reflective layer creates defects in addressable information storage locations on the CD-ROM. The serial number is read by detecting the defects. The serial number is used in a software distribution system in which many different software programs are distributed on a single CD-ROM and an access code based on the desired software program and the serial number of a particular CD-ROM is used to "unlock" the desired program on the particular CD-ROM.
Inventors
- 👤 Barry A. Fite
- 👤 Michael L. Mitchell
- 👤 Russ A. Kunz
- 👤 Clifford R. Brannon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 10:17
CPC Classifications
G; G11; G11B; G11B20/00; G11B20/00086; G11B20/0021; G11B20/00217; G11B20/00253; G11B20/00326; G06; G06F; G06F21/00; G06K; G06K1/00; G06K1/12; G06K1/126; G06K19/00; G06K19/06; G06K19/08; G06K19/10; G06K19/14; G11B20/00094; G11B20/00115; G11B20/00123; G11B20/00246; G11B20/0026; G11B20/00485; G11B20/00557; G11B20/00681; G11B20/00695; G11B20/00876; G11B20/0092; G11B20/00927; G11B23/00; G11B23/28; G11B23/281; G11B23/283; G11B23/284; G11B23/30; G11B23/36; G11B23/38; G11B27/00; G11B27/10; G11B27/102; G11B27/105; G11B27/19; G11B27/24; G11B7/00; G11B7/004; G11B7/005; G11B7/24; G11B7/26; G11B7/002; G11B7/0037
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
141 words
A method of reading a machine-readable code being formed of a first plurality of bits recorded in a corresponding plurality of recording areas on a recording medium, said method comprising the steps of: determining a plurality of defect count values corresponding to said plurality of recording areas, wherein each one of said plurality of defect count values corresponds to a number of defects present in a corresponding one of said plurality of recording areas; assigning a first predetermined bit value to respective ones of said plurality of recording areas having a corresponding defect count value exceeding a predetermined threshold; and assigning a second predetermined bit value to respective ones of said plurality of recording areas having a corresponding defect value less than said predetermined threshold, wherein said machine-readable code corresponds to the bit values assigned to said plurality of recording locations.
Claim 2
Independent Claim
141 words
A method of reading a machine-readable code being formed of a first plurality of bits recorded in a corresponding plurality of recording areas on a recording medium, said method comprising the steps of: determining a plurality of defect count values corresponding to said plurality of recording areas, wherein each one of said plurality of defect count values corresponds to a number of defects present in a corresponding one of said plurality of recording areas; assigning a first predetermined bit value to respective ones of said plurality of recording areas having a corresponding defect count value exceeding a predetermined threshold; and assigning a second predetermined bit value to respective ones of said plurality of recording areas having a corresponding defect value less than said predetermined threshold, wherein said machine-readable code corresponds to the bit values assigned to said plurality of recording locations.
Claim 3
Dependent Claim
39 words
A method according to claim 1, wherein said recording medium comprises a CD-ROM, and wherein said determining step and said assigning steps are performed using a CD-ROM drive interfaced to a personal computer into which said CD-ROM is inserted.
Claim 4
Dependent Claim
21 words
A method according to claim 1, wherein said defects comprise a plurality of predetermined defects intentionally formed onto said recording medium.
References Cited (Backward Citations)
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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) | 1999-07-30 | 2000-01-29 | 2000-07-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-07-30 | 2004-01-29 | 2004-07-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-07-30 | 2008-01-29 | 2008-07-30 | $7700.00 | Window Closed / Lapsed |