US3860766A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical signal reproducing apparatus
Assignee: Toshiba Corp
•
Filing: 1973-05-31
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Granted: 1975-01-14
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Expires: 1993-05-31
Abstract
Abstract In optical signal reproducing apparatus for reproducing a signal from a recording medium having a groove in which the signal has been recorded as continuous irregularities of a sine curve having a pitch of the order of microns, there are provided a source of light for emanating a light beam of a definite phase, means for projecting the light beam upon the groove after limiting the width of the beam to be less than the minimum pitch of the irregularities, and means for detecting the diffracted light reflected by the irregularities.
Inventors
- 👤 Masafumi Mori
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 13:59
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/08; G11B7/09; G11B7/0901; G11B7/004; G11B7/005; G11B7/007; G11B7/12; G11B7/24; G11B7/2407; G11B7/24073; G11B7/24082
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
85 words
Optical signal reproducing apparatus comprising a recording medium including a groove storing a signal as continuous sine curve shaped irregularities having a pitch of the order of microns, a source of light for emanating a light beam of a definite phase, means for projecting said beam upon the groove of said recording medium after limiting the width of said beam to an extent smaller than or equal to the minimum pitch of said irregularities, and means for detecting the diffracted light reflected by said irregularities.
Claim 2
Dependent Claim
85 words
Optical signal reproducing apparatus comprising a recording medium including a groove storing a signal as continuous sine curve shaped irregularities having a pitch of the order of microns, a source of light for emanating a light beam of a definite phase, means for projecting said beam upon the groove of said recording medium after limiting the width of said beam to an extent smaller than or equal to the minimum pitch of said irregularities, and means for detecting the diffracted light reflected by said irregularities.
Claim 3
Dependent Claim
14 words
An apparatus according to claim 1 wherein said light source comprises a gas laser.
Claim 4
Dependent Claim
28 words
An apparatus according to claim 1 wherein said beam projecting means comprises means for forming a flat beam having a width substantially equal to that of said groove.
Claim 5
Dependent Claim
19 words
An apparatus according to claim 1 wherein said recording medium comprises a rotatable disc formed with the spiral groove.
Claim 6
Dependent Claim
29 words
An apparatus according to claim 1 wherein said beam projecting means includes means for projecting said beam at right angles with respect to the groove of said recording medium.
Claim 7
Dependent Claim
42 words
An apparatus according to claim 5 wherein said detecting means is disposed to detect a component of the diffracted light produced by the reflection of said normally projected beam, said component inclining at a predetermined angle with respect to the projected beam.
Claim 8
Dependent Claim
25 words
An apparatus according to claim 6 wherein said detecting means is disposed to detect a component having an angle of inclination of at least 15*.
Claim 9
Dependent Claim
46 words
An apparatus according to claim 6 wherein said detecting means comprises a bundle of optical fibers for transmitting the diffracted light, and means arranged to receive the diffracted light transmitted through said bundle for generating an electric signal corresponding to the intensity of the received light.
Claim 10
Dependent Claim
65 words
An apparatus according to claim 6 wherein said detecting means comprises a pair of bundles of optical fibers disposed along the groove of said recording medium, a pair of photosensitive devices disposed to detect the diffracted light transmitted through respective bundles of optical fibers for converting said diffracted light into electric signals, and a differential circuit for producing a difference signal between said electric signals.
Claim 11
Dependent Claim
32 words
An apparatus according to claim 1 which further includes means for detecting the deviation of the light beam projected upon the groove of said recording means, and means to correct such deviation.
Claim 12
Dependent Claim
62 words
An apparatus according to claim 10 wherein said correcting means comprises a pair of photosensitive devices positioned on the opposite sides of the groove of said recording medium, a differential circuit for producing a difference signal between the outputs of said photosensitive devices, and means for varying the position of the projected light beam by an amount corresponding to said difference signal.
References Cited (Backward Citations)
US3138669A
Cited
US3325603A
Cited
US3452163A
Cited
US3530258A
Cited
US3666896A
Cited
US3699478A
Cited
US3781700A
Cited
US3727062A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-01-13 | 1978-07-15 | 1979-01-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-01-13 | 1982-07-15 | 1983-01-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-01-13 | 1986-07-15 | 1987-01-14 | $7700.00 | Window Closed / Lapsed |