EP0217460A1
Expired / Lapsed
EP
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Apparatus for reading information from a record carrier
Assignee: Koninklijke Philips NV
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Filing: 1986-09-23
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Granted: —
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Expires: 2006-09-23
Abstract
Abstract In addition to the customary servo control devices (15, 18 and 211 for radial tracking, focussing and speed control respectively an apparatus for reading, for example, a Compact Disc (3) comprises three feed-forward control loops (30, 40 and 50) which each comprise an acceleration transducer (31, 41 and 51) which the case of shocks and vibrations give the optical read unit (5) the same angular acceleration, the optical read unit (5) the same linear acceleration and the motor (2) the same angular acceleration as the apparatus (1) itself, so that the apparatus is less sensitive to shocks and vibrations.
Inventors
- 👤 Johannes c/o Int. Octrooibureau B.V. Janssen
- 👤 Gerard c/o Int. Octrooibureau B.V. Van Rosmalen
- 👤 Maarten c/o Int. Octrooibureau B.V. Van Alfen
- 👤 Petrus c/o Int. Octrooibureau B.V. Rouws
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 04:24
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/08; G11B7/09; G11B7/0946; G11B19/00; G11B19/20; G11B19/24; G11B21/00; G11B21/02; G11B21/10; G11B21/106; G11B33/00; G11B33/02; G11B33/08; G11B7/085
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
166 words
An apparatus for at least reading a record carrier provided with a spiral track containing information, which apparatus comprises a motor for driving the record carrier, a read device comprising an optical read unit for reading the information from the record carrier, a signal-processing device for processing the information read, a first control device for controlling the radial position of the read unit relative to the record carrier in response to a radial-error signal generated by the read device, a second control device for controlling the distance between the read unit and the record carrier in response to a focus-error signal generated by the read device, and a third control device for controlling the tangential position of the read unit relative to the record carrier in response to a tangential-error signal generated by the signal processing device, characterized in that the apparatus comprises at least one acceleration transducer for generating a control signal for additional feed-forward control in at least one of the three control devices.
Claim 2
Independent Claim
166 words
An apparatus for at least reading a record carrier provided with a spiral track containing information, which apparatus comprises a motor for driving the record carrier, a read device comprising an optical read unit for reading the information from the record carrier, a signal-processing device for processing the information read, a first control device for controlling the radial position of the read unit relative to the record carrier in response to a radial-error signal generated by the read device, a second control device for controlling the distance between the read unit and the record carrier in response to a focus-error signal generated by the read device, and a third control device for controlling the tangential position of the read unit relative to the record carrier in response to a tangential-error signal generated by the signal processing device, characterized in that the apparatus comprises at least one acceleration transducer for generating a control signal for additional feed-forward control in at least one of the three control devices.
Claim 3
Dependent Claim
53 words
An apparatus as claimed in claim 1, in which the optical read unit is mounted on an arm which is pivotable about an axis, characterized in that the apparatus is provided with an angular-acceleration transducer for generating a control signal for feed-forward control of the arm in conjunction with the first control device.
Claim 4
Dependent Claim
21 words
An apparatus as claimed in Claim 2, characterized in that the angular-acceleration transducer comprises two linear-acceleration transducers with parallel sensitive directions.
Claim 5
Dependent Claim
26 words
An apparatus as claimed in Claim 2, characterized in that the angular-acceleration transducer comprises the signal-processing device, the control signal being constituted by the tangential-error signal.
Claim 6
Dependent Claim
66 words
An apparatus as claimed in Claim 1, in which the optical read unit is mounted on a radially movable slide so as to be movable relative to the slide in at least a radial direction, characterized in that the apparatus is provided with a linear-acceleration transducer for generating a control signal for feed-forward control of the optical read unit in conjunction with the first control device.
Claim 7
Dependent Claim
49 words
An apparatus as claimed in Claim 1, in which the optical read unit is mounted on a radially movable slide, characterized in that the apparatus is provided with a linear-acceleration transducer for generating a control signal for feed-forward control of the slide in conjunction with the first control device.
Claim 8
Dependent Claim
41 words
An apparatus as claimed in Claim 1, 2, 3, 4 " , 5 or 6 characterized in that the apparatus is provided with a linear-acceleration transducer for generating a control signal for feed-forward control in conjunction with the second control device.
Claim 9
Independent Claim
55 words
An apparatus as claimed in any one of the preceding Claims, in which the third control device is adapted to control the speed of the motor, characterized in that the apparatus is provided with an angular-acceleration transducer for generating a control signal for feed-forward control of the motor in conjunction with the third control device.
Claim 10
Dependent Claim
27 words
An apparatus as claimed in Claim 8 as appendant to Claim 2, characterized in that the first and the third feed-forward control comprise one common angular-acceleration transducer.
Claim 11
Independent Claim
89 words
An apparatus as claimed in any one of the preceding Claims 1 to 7, in which the optical read unit is mounted on a radially movable slide, the optical read unit being at least tangentially movable relative to the slide and the third control device being adapted to control the position of the read unit, characterized in that the apparatus is provided with a linear-acceleration transducer for generating a control signal for feed-forward control of the read unit in a tangential direction in conjunction with the third control device.
Claim 12
Dependent Claim
29 words
An apparatus aszclaimed in Claim 2, 3, 5 or 6, 7, 8, 9 or 10, characterized in that the at least one acceleration transducer is a piezo-electric acceleration transducer.
References Cited (Backward Citations)
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