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US3638201A
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US
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Optical data storage system
Assignee: Licentia Patent Verwaltungs GmbH
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Filing: 1970-06-29
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Granted: 1972-01-25
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Expires: 1990-06-29
Abstract
Abstract Damaged or faulty areas of an optical recording medium of the type wherein the data is recorded by means of selective discolorations caused by a writing light beam of a first wavelength are detected by utilizing a control beam of light in addition to the usual readout light beam during the optical nondestructive readout of the data. The control beam has a wavelength which is different from that of the readout beam and will not be absorbed by the discolored portions of the recording medium. The control beam and the readout beam are separately detected and those portions of the recording medium which produce modulation of both the reading and control beams as the result of absorption of both beams are identified as being damaged.
Inventors
- 👤 Manfred Borner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 23:43
CPC Classifications
G; G06; G06F; G06F11/00; G06F11/07; G06F11/0703; G06F11/0751; G11; G11C; G11C13/00; G11C13/04; G11C13/048
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
192 words
In a data storage system in which data are recorded on a storage medium by means of color changes thereof caused by the impingement of high-energy laser beams and is nondestructively read out by means of light beams of a wavelength different from that of the recording beams, which will not cause color changes in said recording medium and will be at least partially absorbed by the changed color portion of the recording medium, the method of determining faulty portions of said recording medium during readout comprising: during the readout of the stored information, simultaneously exposing said recording medium to an additional control beam of light of a wavelength which will not cause color changes of said recording medium and will not be absorbed by the discolorations produced on the recording medium during the recording process; separately detecting said control beam of light; and providing an error signal whenever a modulated control beam, indicating absorption of said control beam by the particular poRtion of the recording medium being readout, is detected, whereby said error signal is an indication that said particular portion of said recording medium is damaged or provides faulty information.
Claim 2
Dependent Claim
192 words
In a data storage system in which data are recorded on a storage medium by means of color changes thereof caused by the impingement of high-energy laser beams and is nondestructively read out by means of light beams of a wavelength different from that of the recording beams, which will not cause color changes in said recording medium and will be at least partially absorbed by the changed color portion of the recording medium, the method of determining faulty portions of said recording medium during readout comprising: during the readout of the stored information, simultaneously exposing said recording medium to an additional control beam of light of a wavelength which will not cause color changes of said recording medium and will not be absorbed by the discolorations produced on the recording medium during the recording process; separately detecting said control beam of light; and providing an error signal whenever a modulated control beam, indicating absorption of said control beam by the particular poRtion of the recording medium being readout, is detected, whereby said error signal is an indication that said particular portion of said recording medium is damaged or provides faulty information.
Claim 3
Dependent Claim
19 words
The method of claim 1 further including utilizing said error signal to control the detector for said reading beam.
Claim 4
Dependent Claim
193 words
In a data storage system in which data are recorded on a storage medium by means of color changes thereof caused by the selective impingement at portions thereof of a beam of light of a first wavelength and is nondestructively read out by means of light beams of a second wavelength, different from that of said first wavelength, which will not cause color changes in said recording medium and will be at least partially absorbed by the changed or discolored portions of said recording medium, the improvement wherein said system includes means for detecting a faulty discolored portion of said record medium during readout comprising: means, operative during the reading out of data from the record medium, for simultaneously subjecting the portion of the record medium being read to a control beam of light of a wavelength which will not cause discoloration in said recording medium and will not be absorbed by the discolored portions of said record medium; means for detecting said control beam and for producing an error signal whenever the detected control beam indicates that absorption thereof by the particular discolored portion of said record medium being readout has occurred.
Claim 5
Dependent Claim
193 words
In a data storage system in which data are recorded on a storage medium by means of color changes thereof caused by the selective impingement at portions thereof of a beam of light of a first wavelength and is nondestructively read out by means of light beams of a second wavelength, different from that of said first wavelength, which will not cause color changes in said recording medium and will be at least partially absorbed by the changed or discolored portions of said recording medium, the improvement wherein said system includes means for detecting a faulty discolored portion of said record medium during readout comprising: means, operative during the reading out of data from the record medium, for simultaneously subjecting the portion of the record medium being read to a control beam of light of a wavelength which will not cause discoloration in said recording medium and will not be absorbed by the discolored portions of said record medium; means for detecting said control beam and for producing an error signal whenever the detected control beam indicates that absorption thereof by the particular discolored portion of said record medium being readout has occurred.
Claim 6
Dependent Claim
49 words
The data system as defined in claim 3 including means, coupling the output of said detecting means to the detecting means in said system for the reading beam, for blocking the received signals from the particular portion of said record medium being read whenever an error signal is produced.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-01-24 | 1975-07-26 | 1976-01-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-24 | 1979-07-26 | 1980-01-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-24 | 1983-07-26 | 1984-01-25 | $7700.00 | Window Closed / Lapsed |