US3739154A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical tracking apparatus for read out of high density recording
Assignee: Ampex Corp
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Filing: 1972-05-01
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Granted: 1973-06-12
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Expires: 1992-05-01
Abstract
Abstract In read-out apparatus which employs an optical scanner with a stationary output beam, a magnified image of an elongated scanning spot may be formed on an array of detectors. As the elongated spot scans the tracks, the track images scan the detector array. Equivalently, the demagnified image of the array may be thought of as moving along the tracks in the scan plane. Skew or flutter causes the track (of plurality of tracks) to move along the detector array, whereby detecting the sequence of change in the orientation between the track and the detectors determines the relative direction of motion of the track. An electronic logic circuit is coupled to the detectors, and generates tracking error signals of magnitudes and polarities which are indicative of the tracking error caused by flutter. The tracking error signals are delivered to the tape transport to provide track position correction. Skew error is compensated via linear gate devices, which switch the detectors to continuously pass the signal of the one track being read to the output, regardless of which detector or pairs of detectors, is temporarily aligned with that track.
Inventors
- 👤 J Corcoran
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 22:23
CPC Classifications
G; G06; G06V; G06V30/00; G06V30/10; G06V30/14; G06V30/146; G06V30/1475; G06V30/1478; G06K; G06K7/00; G06K7/01; G06K7/015; G11; G11B; G11B15/00; G11B15/60; G11B15/602; G11B7/00; G11B7/08; G11B7/09; G11B7/0901
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
153 words
A tracking system for optical readout apparatus adapted to read successive tracks in a recorded medium, and for providing data output signals representing the information recorded on the tracks, said optical readout apparatus having a stationary output beam, comprising the combination of: optical means including an elongated scan spot for scanning a plurality of tracks simultaneously; means operatively coupled to the tracks for generating data signals indicative of the information on the plurality of tracks in response to the simultaneous impingement of the tracks by the elongated scan spot; logic circuit means coupled to the means for generating for receiving the data signals and for providing a transport servo signal for controlling the position of a single selected track of the plurality relative to the means for generating; said logic circuit means further providing digital signals which continuously select the data signals from he single selected track to define the data output signals.
Claim 2
Dependent Claim
153 words
A tracking system for optical readout apparatus adapted to read successive tracks in a recorded medium, and for providing data output signals representing the information recorded on the tracks, said optical readout apparatus having a stationary output beam, comprising the combination of: optical means including an elongated scan spot for scanning a plurality of tracks simultaneously; means operatively coupled to the tracks for generating data signals indicative of the information on the plurality of tracks in response to the simultaneous impingement of the tracks by the elongated scan spot; logic circuit means coupled to the means for generating for receiving the data signals and for providing a transport servo signal for controlling the position of a single selected track of the plurality relative to the means for generating; said logic circuit means further providing digital signals which continuously select the data signals from he single selected track to define the data output signals.
Claim 3
Dependent Claim
44 words
The tracking system of claim 1 wherein the means for generating data signals includes an array of deteCtors optically disposed across the tracks to cause the track images to scan along the array of detectors as the elongated spot scans the plurality of tracks.
Claim 4
Dependent Claim
51 words
The tracking system of claim 2 wherein said logic circuit means is coupled to the array of detectors to generate the transport servo signal in response to the detector outputs, which servo signal is indicative of the position of the single selected track relative to the length of the detector array.
Claim 5
Dependent Claim
40 words
The tracking system of claim 3 wherein said logic circuit means further includes gating means operatively responsive to the digital signals to continuously provide passage of data signals indicative of the track being scanned to define the data output signals.
Claim 6
Dependent Claim
84 words
The tracking system of claim 4 wherein said logic circuit means includes an analog subtractor circuit coupled to a selected pair of the detectors and adapted to provide a signal equal to the difference between the data signals from the pair of detectors to define the transport servo signal, said analog subtractor circuit being coupled to a third selected detector and adapted to provide said digital signals indicative of the direction of movement of the plurality of tracks relative to the array of detectors.
Claim 7
Dependent Claim
50 words
The tracking system of claim 5 further including a plurality of analog gates coupled to the series of detectors in the detector array, said analog gates being responsive to said digital signals to continuously select the data signals from the single selected track to define therefrom the data output signals.
Claim 8
Dependent Claim
145 words
The tracking system of claim 6 wherein said analog subtractor circuit further includes a pair of analog amplifiers wherein a first and third of the detectors of said selected detectors are coupled to respective analog amplifiers, and the second detector is coupled to both the analog amplifiers, diode means coupled to the output lines of each analog amplifier, and a third analog amplifier coupled to the pairs of diodes and providing an analog output in quadrature with the output delivered to the transport servo circuit; and said logic circuit including first and second analog-to-digital comparator circuits disposed to receive the analog signals from the first and second analog amplifiers to provide a ''''1'''' output in response to a positive input, and a ''''0'''' output in response to a negative input, said ''''1'''' and ''''0'''' signals defining said digital signals for selectively actuating said analog gates.
Claim 9
Dependent Claim
57 words
The tracking system of claim 7 further including up/down counter means disposed to receive the digital signals, and adapted to count up in response thereto when the track movement is in a direction towards higher numbered detectors, and to count down when the track movement is in the direction of lowered numbered detectors of said detector array.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-06-11 | 1976-12-11 | 1977-06-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-11 | 1980-12-11 | 1981-06-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-11 | 1984-12-11 | 1985-06-12 | $7700.00 | Window Closed / Lapsed |