US4145758A
Expired / Lapsed
US
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Error checking method and apparatus for digital data in optical recording systems
Assignee: LaserCard Corp
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Filing: 1977-10-25
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Granted: 1979-03-20
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Expires: 1997-10-25
Abstract
Abstract An error checking method and apparatus for recording digital data in an optical recording medium. Digital data are written onto the medium by a modulated laser whose beam is detected by a first photodetector means which measures laser output directed toward the recording medium. A second photodetector means measures light scattering from the medium, while a third photodetector detects and measures light transmitted through the recording layer of the medium serving to confirm recording of the data. Amounts of transmitted light or scattered light from the medium are correlated to the laser output and to expected values of light for detecting errors in recording immediately after the time of recording. Reversal processing of the recording medium eliminates a large fraction of potential errors.
Inventors
- 👤 Jerome Drexler
- 👤 Carl R. Betz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 21:55
CPC Classifications
G; G06; G06F; G06F11/00; G06F11/07; G06F11/0703; G06F11/0751; G06F11/16; G06F11/20; G11; G11B; G11B20/00; G11B20/10; G11B20/18; G11B20/1883; G11B27/00; G11B27/10; G11B27/19; G11B27/28; G11B27/32; G11B7/00; G11B7/004; G11B2220/00; G11B2220/20
Claims Analysis
Total Claims: 37
Claim 1
Independent Claim
116 words
An error detecting system for an optical data recording apparatus comprising, an optical recording medium having a recording layer which is light transmissive prior to recording data on at least one side thereof, light beam means positioned for writing optical pulses on said recording medium in selected locations, a pair of photodetector means positioned for receiving optical energy scattered from said recording medium and optical energy passing through the recording layer of the recording medium, said pair of photodetctor means generating first and second electrical signals indicative of the energy received from said pulses, and correlating means connected to receive said first and second electrical signals for signalling data errors in writing on said recording medium.
Claim 2
Dependent Claim
116 words
An error detecting system for an optical data recording apparatus comprising, an optical recording medium having a recording layer which is light transmissive prior to recording data on at least one side thereof, light beam means positioned for writing optical pulses on said recording medium in selected locations, a pair of photodetector means positioned for receiving optical energy scattered from said recording medium and optical energy passing through the recording layer of the recording medium, said pair of photodetctor means generating first and second electrical signals indicative of the energy received from said pulses, and correlating means connected to receive said first and second electrical signals for signalling data errors in writing on said recording medium.
Claim 3
Dependent Claim
42 words
The system of claim 1 wherein one of said photodetector means is disposed in the path of said optical pulses on a side of said optical recording medium opposite of said light beam means for confirming writing on said optical recording medium.
Claim 4
Dependent Claim
17 words
The apparatus of claim 1 wherein said light beam means is a laser of a selected wavelength.
Claim 5
Dependent Claim
24 words
The apparatus of claim 3 wherein said pair of photodetector means comprises photodetectors having sensitivity strongly peaked in the selected wavelength of said laser.
Claim 6
Dependent Claim
52 words
The apparatus of claim 1 wherein a coincidence detection means is connected on the one hand to an input modulation signal causing said optical pulses in said light beam means and on the other hand to one of said photodetector means, for detecting transmission of optical pulses toward said optical recording medium.
Claim 7
Dependent Claim
39 words
The apparatus of claim 1 wherein a coincidence detection means is connected to said pair of photodetector means for detecting anticoincident activation by said light beam when one of said photodetector means detects light scattering from said recording medium.
Claim 8
Dependent Claim
21 words
The apparatus of claim 1 wherein said optical recording medium is a glass, circular photoplate disk coated with photo sensitive material.
Claim 9
Dependent Claim
21 words
The apparatus of claim 1 wherein said optical recording medium is a plastic, circular photoplate disk coated with photo sensitive material.
Claim 10
Dependent Claim
32 words
The apparatus of claim 1 wherein said light beam means comprises optical means for simultaneously writing the same optical pulses on two spaced apart locations on the same side of sid photoplate.
Claim 11
Dependent Claim
172 words
An optical data recording system comprising, an optical recording medium having a light transmissive recording layer on at least one side thereof, light beam means positioned for writing optical pulses on said recording medium in selected locations, first photodetector means positioned for receiving a portion of the energy from said optical pulses directed toward said recording medium and generating a first electrical signal indicative of the energy intensity received from said pulses, second photodetector means positioned for receiving a portion of the energy from said optical pulses, said energy scattered from said recording medium and generating a second electrical signal indicative of the energy intensity received from said pulses, third photodetector means positioned for receiving a portion of the energy from said optical pulses which passes through the recording layer of said recording medium, and generating a third electrical signal indicative of the energy intensity received from said pulses, and correlating means connected to receive said first, second, and third electrical signals for signalling data errors in writing on said recording surface.
Claim 12
Dependent Claim
172 words
An optical data recording system comprising, an optical recording medium having a light transmissive recording layer on at least one side thereof, light beam means positioned for writing optical pulses on said recording medium in selected locations, first photodetector means positioned for receiving a portion of the energy from said optical pulses directed toward said recording medium and generating a first electrical signal indicative of the energy intensity received from said pulses, second photodetector means positioned for receiving a portion of the energy from said optical pulses, said energy scattered from said recording medium and generating a second electrical signal indicative of the energy intensity received from said pulses, third photodetector means positioned for receiving a portion of the energy from said optical pulses which passes through the recording layer of said recording medium, and generating a third electrical signal indicative of the energy intensity received from said pulses, and correlating means connected to receive said first, second, and third electrical signals for signalling data errors in writing on said recording surface.
Claim 13
Dependent Claim
112 words
An error detecting system for an optical data recording apparatus comprising, an optical recording medium having a recording layer which is light transmissive prior to recording data on at least one side thereof, light beam means positioned for writing optical pulses on said recording medium in selected locations, a pair of photodetector means positioned for receiving optical energy directed toward said recording medium and optical energy scattered from said recording medium, said pair of photodetector means generating first and second electrical signals indicative of the energy received from said pulses, and correlating means connected to receive said first and second electrical signals for signalling data errors in writing on said recording medium.
Claim 14
Dependent Claim
112 words
An error detecting system for an optical data recording apparatus comprising, an optical recording medium having a recording layer which is light transmissive prior to recording data on at least one side thereof, light beam means positioned for writing optical pulses on said recording medium in selected locations, a pair of photodetector means positioned for receiving optical energy directed toward said recording medium and optical energy scattered from said recording medium, said pair of photodetector means generating first and second electrical signals indicative of the energy received from said pulses, and correlating means connected to receive said first and second electrical signals for signalling data errors in writing on said recording medium.
Claim 15
Dependent Claim
33 words
The system of claim 11 wherein one of said photodetector means is disposed in the path of optical pulses on the same side of said optical recording medium as said light beam means.
Claim 16
Dependent Claim
52 words
The apparatus of claim 11 wherein a coincidence detection means is connected on the one hand to an input modulation signal causing said optical pulses in said light beam means and on the other hand to one of said photodetector means, for detecting transmission of optical pulses toward said optical recording medium.
Claim 17
Dependent Claim
39 words
The apparatus of claim 11 wherein a coincidence detection means is connected to said pair of photodetector means for detecting anticoincident activation by said light beam when one of said photodetector means detects light scattering from said recording medium.
Claim 18
Dependent Claim
32 words
The apparatus of claim 11 wherein said light beam means is a laser and said pair of photodetector means comprises photodetectors having sensitivity strongly peaked in the selected wavelength of said laser.
Claim 19
Dependent Claim
118 words
An error detecting system for an optical data recording apparatus comprising, an optical recording medium having a recording layer which is light transmissive prior to recording data on at least one side thereof, light beam means positioned for writing optical pulses on said recording medium in selected locations, a pair of photodetector means positioned for receiving optical energy directed toward said recording medium and for receiving optical energy passing through the recording layer of the recording medium, said pair of photodetector means generating first and second electrical signals indicative of the energy received from saidd pulses, and correlating means connected to receive said first and second electrical signals for signalling data errors in writing on said recording medium.
Claim 20
Dependent Claim
118 words
An error detecting system for an optical data recording apparatus comprising, an optical recording medium having a recording layer which is light transmissive prior to recording data on at least one side thereof, light beam means positioned for writing optical pulses on said recording medium in selected locations, a pair of photodetector means positioned for receiving optical energy directed toward said recording medium and for receiving optical energy passing through the recording layer of the recording medium, said pair of photodetector means generating first and second electrical signals indicative of the energy received from saidd pulses, and correlating means connected to receive said first and second electrical signals for signalling data errors in writing on said recording medium.
Claim 21
Dependent Claim
33 words
The system of claim 16 wherein one of said photodetector means is disposed in the path of optical pulses on the same side of said optical recording medium as said light beam means.
Claim 22
Dependent Claim
52 words
The system of claim 16 wherein a coincidence detection means is connected on the one hand to an input modulation signal causing said optical pulses in said light beam means and on the other hand to one of said photodetector means, for detecting transmission of optical pulses toward said optical recording medium.
Claim 23
Dependent Claim
13 words
The system of claim 16 wherein said light beam means is a laser.
Claim 24
Independent Claim
89 words
A method of recording and error checking optical pulses on an optical recording medium comprising, directing optical pulses from a light souce at an optical recording medium which is light transmissive prior to recording data, detecting optical energy scattered from said recording medium, detecting optical energy passing through the recording layer of the recording medium, and generating corresponding first and second electrical signals indicative of the energy received from said pulses, and correlating said first and second electrical signals for signalling data errors in writing on said recording medium.
Claim 25
Independent Claim
89 words
A method of recording and error checking optical pulses on an optical recording medium comprising, directing optical pulses from a light souce at an optical recording medium which is light transmissive prior to recording data, detecting optical energy scattered from said recording medium, detecting optical energy passing through the recording layer of the recording medium, and generating corresponding first and second electrical signals indicative of the energy received from said pulses, and correlating said first and second electrical signals for signalling data errors in writing on said recording medium.
Claim 26
Dependent Claim
27 words
The method of claim 20 further defined by reversal processing of said optical recording medium, said optical recording medium comprising a substrate and a photo sensitive emulsion.
Claim 27
Dependent Claim
21 words
The method of claim 20 further defined by encoding data in said optical pulses by means of an error correcting code.
Claim 28
Dependent Claim
15 words
The method of claim 20 further defined by using data recording patterns for error detection.
Claim 29
Independent Claim
85 words
A method of recording and error checking optical pulses on an optical recording medium comprising, directing optical pulses from a light souce at an optical recording medium which is light transmissive prior to recording data, detecting optical energy directed toward said recording medium and detecting optical energy scattered from said recording medium, generating corresponding first and second electrical signals indicative of the energy received from said pulses, and correlating said first and second electrical signals for signalling data errors in writing on said recording medium.
Claim 30
Independent Claim
85 words
A method of recording and error checking optical pulses on an optical recording medium comprising, directing optical pulses from a light souce at an optical recording medium which is light transmissive prior to recording data, detecting optical energy directed toward said recording medium and detecting optical energy scattered from said recording medium, generating corresponding first and second electrical signals indicative of the energy received from said pulses, and correlating said first and second electrical signals for signalling data errors in writing on said recording medium.
Claim 31
Dependent Claim
27 words
The method of claim 24 further defined by reversal processing of said optical recording medium, said optical recording medium comprising a substrate and a photo sensitive emulsion.
Claim 32
Dependent Claim
21 words
The method of claim 24 further defined by encoding data in said optical pulses by means of an error correcting code.
Claim 33
Dependent Claim
15 words
The method of claim 24 further defined by using data recording patterns for error detection.
Claim 34
Independent Claim
85 words
A method of recording and error checking optical pulses on an optical recording medium comprising, directing optical pulses from a light source at an optical recording medium which is light transmissive prior to recording data, detecting optical energy directed toward said recording medium and detecting optical energy transmitted through said recording medium, generating corresponding first and second electrical signals indicative of the energy received from said pulses, and correlating said first and second electrical signals for signalling data errors in writing on said recording medium.
Claim 35
Independent Claim
85 words
A method of recording and error checking optical pulses on an optical recording medium comprising, directing optical pulses from a light source at an optical recording medium which is light transmissive prior to recording data, detecting optical energy directed toward said recording medium and detecting optical energy transmitted through said recording medium, generating corresponding first and second electrical signals indicative of the energy received from said pulses, and correlating said first and second electrical signals for signalling data errors in writing on said recording medium.
Claim 36
Dependent Claim
21 words
The method of claim 28 further defined by encoding data in said optical pulses by means of an error correcting code.
Claim 37
Dependent Claim
15 words
The method of claim 28 further defined by using data recording patterns for error detection.
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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) | 1982-03-19 | 1982-09-18 | 1983-03-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-03-19 | 1986-09-18 | 1987-03-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-03-19 | 1990-09-18 | 1991-03-20 | $7700.00 | Window Closed / Lapsed |