US4845698A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of skipping tracks while searching for a track and circuitry for carrying out the method
Assignee: Deutsche Thomson Brandt GmbH
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Filing: 1986-05-30
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Granted: 1989-07-04
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Expires: 2006-05-30
Abstract
Abstract Process for track jumping in track searching process for a rotating information carrier scanned with an optical system, in which the system works in conjunction with a radial coarse (13) and fine (3) drive system. If the coarse drive is immediately put into operation in accordance with the input search direction, the servocircuit of the fine drive system is initially closed and is only opened as a function of criteria prevailing at the time. In this process and in the circuit arrangement envisaged for its implementation, the principal advantage is a high search speed and considerable initial acceleration. In particular, the movement overlaps occurring in the starting phase do not present a problem for the perfect operation of the process.
Inventors
- 👤 Dieter Baas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 11:22
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/08; G11B7/085; G11B7/08505; G11B7/08517
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
77 words
A method of skipping tracks while searching for a track on a rotating information base scanned with an optical system, comprising the steps: operating the system with radial coarse-drive means and with radial fine-drive means; starting said coarse-drive means immediately in a given search direction during track-seeking procedures carried out with said coarse drive means and holding said fine-drive means initially inoperative; selecting predetermined operating conditions subsequently and operating said fine-drive means only dependent on said conditions.
Claim 2
Independent Claim
77 words
A method of skipping tracks while searching for a track on a rotating information base scanned with an optical system, comprising the steps: operating the system with radial coarse-drive means and with radial fine-drive means; starting said coarse-drive means immediately in a given search direction during track-seeking procedures carried out with said coarse drive means and holding said fine-drive means initially inoperative; selecting predetermined operating conditions subsequently and operating said fine-drive means only dependent on said conditions.
Claim 3
Dependent Claim
90 words
Apparatus for skipping tracks while searching for a track on a rotating information base scanned with an optical system, comprising: radial coarse-drive means and radial fine-drive means for operating the system; means for starting said coarse-drive means immediately in a given search direction during track-seek-procedures carried out with said coarse-drive means and holding said fine-drive means initially inoperative; and means for operating said fine-drive means only dependent on criteria obtained subsequently; said fine-drive means comprising servo means; and detector means for actuating said servo means to operate said fine-drive means.
Claim 4
Dependent Claim
90 words
Apparatus for skipping tracks while searching for a track on a rotating information base scanned with an optical system, comprising: radial coarse-drive means and radial fine-drive means for operating the system; means for starting said coarse-drive means immediately in a given search direction during track-seek-procedures carried out with said coarse-drive means and holding said fine-drive means initially inoperative; and means for operating said fine-drive means only dependent on criteria obtained subsequently; said fine-drive means comprising servo means; and detector means for actuating said servo means to operate said fine-drive means.
Claim 5
Dependent Claim
13 words
Apparatus as defined in claim 2, wherein said detector comprises a zero-point detector.
Claim 6
Dependent Claim
13 words
Apparatus as defined in claim 2, wherein said detector has a variable threshold.
Claim 7
Dependent Claim
27 words
Apparatus as defined in claim 2, comprising further two threshold detectors for distinguishing between forward and backward search directions, each threshold detector being associated with one direction.
Claim 8
Dependent Claim
21 words
Apparatus as defined in claim 2, comprising further a plurality of threshold detectors for distinguishing between forward and backward search directions.
Claim 9
Dependent Claim
17 words
Apparatus as defined in claim 2, including analog-to-digital converters for distinguishing between forward and backward search directions.
Claim 10
Dependent Claim
24 words
Apparatus as defined in claim 2, including delay means for actuating said fine-drive means to an operative state only after a predetermined time delay.
Claim 11
Dependent Claim
25 words
Apparatus as defined in claim 2, including variable delay means for actuating said fine-drive means to an operative state only after a variable time delay.
Claim 12
Dependent Claim
124 words
Apparatus for skipping tracks while searching for a track on a rotating information base scanned with an optical system, comprising: radial coarse-drive means and radial fine-drive means for operating the system; means for starting said coarse-drive means immediately in a given search direction during track-seek-procedures carried out with said coarse-drive means and holding said fine-drive means initially inoperative; and means for operating said fine-drive means only dependent on criteria obtained subsequently; said fine-drive means comprising servo means; and detector means for actuating said servo means to operate said fine-drive means; variable delay means for actuating said fine-drive means to an operative state only after a variable delay, said variable delay being determined by extent and direction of radial eccentricity detected during playback starting phase.
Claim 13
Dependent Claim
124 words
Apparatus for skipping tracks while searching for a track on a rotating information base scanned with an optical system, comprising: radial coarse-drive means and radial fine-drive means for operating the system; means for starting said coarse-drive means immediately in a given search direction during track-seek-procedures carried out with said coarse-drive means and holding said fine-drive means initially inoperative; and means for operating said fine-drive means only dependent on criteria obtained subsequently; said fine-drive means comprising servo means; and detector means for actuating said servo means to operate said fine-drive means; variable delay means for actuating said fine-drive means to an operative state only after a variable delay, said variable delay being determined by extent and direction of radial eccentricity detected during playback starting phase.
Claim 14
Dependent Claim
18 words
Apparatus as defined in claim 10, wherein said variable delay is partly dependent on the detected skip width.
Claim 15
Dependent Claim
25 words
Apparatus as defined in claim 2, including means for ensuring that a radial eccentricity corresponding to a predetermined search direction is delayed to avoid overshoots.
Claim 16
Dependent Claim
113 words
Apparatus for skipping tracks while searching for a track on a rotating information base scanned with an optical system, comprising: radial coarse-drive means and radial fine-drive means for operating the system; means for starting said coarse-drive means immediately in a given search direction during track-seek-procedures carried out with said coarse-drive means and holding said fine-drive means initially inoperative; and means for operating said fine-drive means only dependent on criteria obtained subsequently; said fine-drive means comprising servo means; and detector means for actuating said servo means to operate said fine-drive means; and means for actuating said fine-drive means to an operative state only when a scanning beam has been forceably extracted from a track.
Claim 17
Dependent Claim
113 words
Apparatus for skipping tracks while searching for a track on a rotating information base scanned with an optical system, comprising: radial coarse-drive means and radial fine-drive means for operating the system; means for starting said coarse-drive means immediately in a given search direction during track-seek-procedures carried out with said coarse-drive means and holding said fine-drive means initially inoperative; and means for operating said fine-drive means only dependent on criteria obtained subsequently; said fine-drive means comprising servo means; and detector means for actuating said servo means to operate said fine-drive means; and means for actuating said fine-drive means to an operative state only when a scanning beam has been forceably extracted from a track.
Claim 18
Dependent Claim
26 words
Apparatus as defined in claim 13, including means for deriving also the instant at which said fine-drive means becomes operative from extent of a skip width.
Claim 19
Dependent Claim
22 words
Apparatus as defined in claim 13, wherein said fine-drive means has amplification means with amplification decrease during the coarse-drive means starting phase.
Claim 20
Dependent Claim
27 words
Apparatus as defined in claim 2, wherein the coarse-drive means acceleration phase has a predetermined interval and search speed of said coarse-drive means has a predetermined magnitude.
References Cited (Backward Citations)
US4598394A
Cited
US4623994A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-07-03 | 1993-01-02 | 1993-07-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-07-03 | 1997-01-02 | 1997-07-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-07-03 | 2001-01-02 | 2001-07-04 | $7700.00 | Window Closed / Lapsed |