EP1671320A2 - Appareil du type unite de disque - Google Patents

Appareil du type unite de disque

Info

Publication number
EP1671320A2
EP1671320A2 EP04770107A EP04770107A EP1671320A2 EP 1671320 A2 EP1671320 A2 EP 1671320A2 EP 04770107 A EP04770107 A EP 04770107A EP 04770107 A EP04770107 A EP 04770107A EP 1671320 A2 EP1671320 A2 EP 1671320A2
Authority
EP
European Patent Office
Prior art keywords
signal
signals
disc
ren
mirn
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP04770107A
Other languages
German (de)
English (en)
Inventor
Marcel F. Heertjes
Franciscus L. M. Cremers
Frank B. Sperling
George A. L. Leenknegt
Horst Rumpf
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Koninklijke Philips NV
Original Assignee
Koninklijke Philips Electronics NV
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Koninklijke Philips Electronics NV filed Critical Koninklijke Philips Electronics NV
Priority to EP04770107A priority Critical patent/EP1671320A2/fr
Publication of EP1671320A2 publication Critical patent/EP1671320A2/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/08—Disposition or mounting of heads or light sources relatively to record carriers
    • G11B7/09—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam or focus plane for the purpose of maintaining alignment of the light beam relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following
    • G11B7/0948—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam or focus plane for the purpose of maintaining alignment of the light beam relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following specially adapted for detection and avoidance or compensation of imperfections on the carrier, e.g. dust, scratches, dropouts
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/08—Disposition or mounting of heads or light sources relatively to record carriers
    • G11B7/09—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam or focus plane for the purpose of maintaining alignment of the light beam relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
    • G11B20/10—Digital recording or reproducing
    • G11B20/18—Error detection or correction; Testing, e.g. of drop-outs
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/08—Disposition or mounting of heads or light sources relatively to record carriers
    • G11B7/09—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam or focus plane for the purpose of maintaining alignment of the light beam relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following
    • G11B7/0941—Methods and circuits for servo gain or phase compensation during operation
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/08—Disposition or mounting of heads or light sources relatively to record carriers
    • G11B7/09—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam or focus plane for the purpose of maintaining alignment of the light beam relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following
    • G11B7/0946—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam or focus plane for the purpose of maintaining alignment of the light beam relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following specially adapted for operation during external perturbations not related to the carrier or servo beam, e.g. vibration

Definitions

  • the present invention relates in general to an optical disc drive apparatus for writing/reading information into/from an optical storage disc.
  • an optical storage disc comprises at least one track, either in the form of a continuous spiral or in the form of multiple concentric circles, of storage space where information may be stored in the form of a data pattern.
  • Optical discs may be read-only type, where information is recorded during manufacturing, which information can only be read by a user.
  • the optical storage disc may also be a writeable type, where infonnation may be stored by a user.
  • an optical disc drive comprises, on the one hand, rotating means for receiving and rotating an optical disc, and on the other hand optical means for generating an optical beam, typically a laser beam, and for scanning the storage track with said laser beam.
  • an optical disc drive typically comprises a motor, which drives a hub engaging a central portion of the optical disc.
  • the motor is implemented as a spindle motor, and the motor-driven hub may be arranged directly on the spindle axle of the motor.
  • an optical disc drive For optically scanning the rotating disc, an optical disc drive comprises a light beam generator device (typically a laser diode), an objective lens for focussing the light beam in a focal spot on the disc, and an optical detector for receiving the reflected light reflected from the disc and for generating an electrical detector output signal.
  • the optical detector comprises multiple detector segments, each segment providing an individual segment output signal.
  • the light beam should remain focussed on the disc.
  • the objective lens is arranged axially displaceable, and the optical disc drive comprises focal actuator means for controlling the axial position of the objective lens. Further, the focal spot should remain aligned with a track or should be capable of being positioned with respect to a new track.
  • the optical disc drive comprises radial actuator means for controlling the radial position of the objective lens.
  • the objective lens is arranged tiltably, and such optical disc drive comprises tilt actuator means for controlling the tilt angle of the objective lens.
  • the optical disc drive comprises a controller, which receives an output signal from the optical detector. From this signal, hereinafter also referred to as read signal, the controller derives one or more error signals, such as for instance a focus error signal, a radial error signal, and, on the basis of these error signals, the controller generates actuator control signals for controlling the actuators such as to reduce or eliminate position errors.
  • the controller shows a certain control characteristic.
  • control characteristic is a feature of the controller, which may be described as the way in which the controller behaves as reaction to detecting position errors.
  • Position errors may, in practice, be caused by different types of disturbances.
  • the first category comprises internal disc defects like black dots, pollution like fingerprints, damage like scratches, etc.
  • the second category comprises shocks caused by an object colliding to the disc drive, but shocks and vibrations are mainly to be expected in portable disc drives and automobile applications.
  • an important distinction between disc defects on the one hand and shocks and vibration on the other hand is the frequency range of signal disturbances: signal disturbances caused by disc defects are typically high-frequency, while shocks and vibrations are typically low- frequency.
  • a problem in this respect is that adequately handling disturbances of the first category requires a different control characteristic than adequately handling disturbances of the second category.
  • the controller of a disc drive has a fixed control characteristic, which is either specifically adapted for adequately handling disturbances of the first category (in which case error control is not optimal in the case of disturbances of the second category) or specifically adapted for adequately handling disturbances of the second category (in which case error control is not optimal in the case of disturbances of the first category), or the control characteristic is a compromise (in which case error control is not optimal in the case of disturbances of the first category as well as in the case of disturbances of the second category).
  • a controller applies linear control technique, there is always a compromise between low-frequency disturbance rejection and high-frequency sensitivity to measuring noise.
  • US patent 4.722.079 In order to be able to implement a controller having variable gain, it is necessary to determine which class of disturbance is at hand.
  • Said US patent 4.722.079 describes a system where an optical read signal is processed to determine disturbance class, but this system requires a 3 -beam optical system.
  • US patent 5.867.461 also describes a system where an optical read signal is processed to determine disturbance class. In this known system, the envelope is determined ' of the high frequency signal contents.
  • One disadvantage of this method is that it relies on data written on the disc; it is not applicable in the case of blank discs.
  • Another disadvantage is that this method requires complicated circuitry, inter alia for detecting upper peaks and lower peaks, for filtering in order to detect upper envelope and lower envelope, for analysing these envelopes, and for storing signals in a memory.
  • a general problem relates to adapting the control characteristics in a disc drive which should be capable of handling mechanical shocks as well as disc defects. Changing the control characteristics such that one type of disturbance is handled better may seriously affect the controller's capability to handle a disturbance of another type. Further, the present inventors have found that a single detection signal is not always a reliable source of information for discriminating between mechanical shocks and disc defects.
  • a general objective of the present invention is to provide a method for determining more reliably whether an event corresponds to the occurrence of a mechanical shock or a disc defect. Further, it is an objective of the present invention to provide a method for determining disturbance class which can be implemented relatively easily. Further, it is an objective of the present invention to provide a method for changing control characteristics of the controller on the basis of the results of the above- mentioned determinations.
  • a method for discriminating different types of disturbances in a disc drive apparatus is based on receiving and processing at least two types of signals, each derived from the detector signal.
  • a signal of first type is a signal which is based on summation of two or more individual segment output signals; a preferred signal of first type is generated by generating a summation, possibly a weighed summation, of the individual segment output signals of all detector segments.
  • Such signal of type 1 is a measure for the reflectivity of the disc (i.e. "disc quality"), and will mainly be sensitive to disc defects.
  • a signal of second type is a signal which is based on summation of two or more individual segment output signals, wherein at least one of those signals is multiplied by -1. Such signal of type 2 will merely indicate the occurrence of a position error. Signals of first type may give a certain response, indicating a disc defect or a shock; likewise, signals of second type may give a certain response in the case of a disc defect or a shock. According to a second important aspect of the present invention, a disc defect or a shock is only determined if both signals of first and second type are in agreement with each other, so the chance on erroneous judgement is reduced. It is noted that a distinction between shocks in vertical direction (i.e. parallel to the disc rotation axis) and shocks in horizontal direction (i.e. perpendicular to the disc rotation axis) can be made by taking into account the focus error signal or the radial error signal, respectively.
  • Figure 1A schematically illustrates relevant components of an optical disc drive apparatus
  • Figure IB schematically illustrates an embodiment of an optical detector in more detail
  • Figure 2 is a block diagram schematically illustrating an actuator control circuit
  • Figure 3 is a graph schematically illustrating a function for varying a parameter of the actuator control circuit
  • Figure 4 is a timing diagram of signals for illustrating the operation of the present invention.
  • Figure 1A schematically illustrates an optical disc drive apparatus 1, suitable for storing information on or reading information from an optical disc 2, typically a DVD or a CD.
  • the disc drive apparatus 1 comprises a motor 4 fixed to a frame (not shown for sake of simplicity), defining a rotation axis 5.
  • the disc drive apparatus 1 further comprises an optical system 30 for scanning tracks (not shown) of the disc 2 by an optical beam. More specifically, in the exemplary arrangement illustrated in figure 1A, the optical system 30 comprises a light beam generating means 31, typically a laser such as a laser diode, arranged to generate a light beam 32.
  • the light beam 32 passes a beam splitter 33, a collimator lens 37 and an objective lens 34 to reach (beam 32b) the disc 2.
  • the objective lens 34 is designed to focus the light beam 32b in a focal spot F on a recording layer (not shown for sake of simplicity) of the disc.
  • the light beam 32b reflects from the disc 2 (reflected light beam 32c) and passes the objective lens 34, the collimator lens 37, and the beam splitter 33, to reach (beam 32d) an optical detector 35.
  • the disc drive apparatus 1 further comprises an actuator system 50, which comprises a radial actuator 51 for radially displacing the objective lens 34 with respect to the disc 2. Since radial actuators are known per se, while the present invention does not relate to the design and functioning of such radial actuator, it is not necessary here to discuss the design and functioning of a radial actuator in great detail.
  • said objective lens 34 is mounted axially displaceable, while further the actuator system 50 also comprises a focal actuator 52 arranged for axially displacing the objective lens 34 with respect to the disc 2.
  • the objective lens 34 may be mounted pivotably; in such case, as shown, the actuator system 50 also comprises a tilt actuator 53 arranged for pivoting the objective lens 34 with respect to the disc 2. Since tilt actuators are known per se, while further the design and operation of such tilt actuator is no subject of the present invention, it is not necessary here to discuss the design and operation of such tilt actuator in great detail.
  • means for supporting the objective lens with respect to an apparatus frame and means for axially and radially displacing the objective lens, as well as means for pivoting the objective lens, are generally known per se. Since the design and operation of such supporting and displacing means are no subject of the present invention, it is not necessary here to discuss their design and operation in great detail. It is further noted that the radial actuator 51, the focal actuator 52 and the tilt actuator 53 may be implemented as one integrated actuator.
  • the disc drive apparatus 1 further comprises a control circuit 90 having a first output 92 connected to a control input of the motor 4, having a second output 93 coupled to a control input of the radial actuator 51, having a third output 94 coupled to a control input of the focal actuator 52, and having a fourth output 95 coupled to a control input of the tilt actuator 53.
  • the control circuit 90 is designed to generate at its first output 92 a control signal SCM f° r controlling the motor 4, to generate at its second control output 93 a control signal SCR for controlling the radial actuator 51, to generate at its third output 94 a control signal SCF f° r controlling the focal actuator 52, and to generate at its fourth output 95 a control signal SCT for controlling the tilt actuator 53.
  • the control circuit 90 further has a read signal input 91 for receiving a read signal SR from the optical detector 35.
  • Figure IB illustrates that the optical detector 35 may comprise a plurality of detector segments.
  • the optical detector 35 comprises six detector segments 35a, 35b, 35c, 35d, 35e, 35f, capable of providing individual detector signals A, B, C, D, SI, S2, respectively, indicating the amount of light incident on each of the six detector segments, respectively.
  • Four detector segments 35a, 35b, 35c, 35d also indicated as central aperture detector segments, are arranged in a four-quadrant configuration.
  • a centre line 36 separating the first and fourth segments 35a and 35d from the second and third segments 35b and 35c, has a direction corresponding to the track direction.
  • Two detector segments 35e, 35f also indicated as satellite detector segments, and which may themselves be subdivided into subsegments, are arranged symmetrically besides the central detector quadrant, on opposite sides of said centre line 36. Since such six-segment detector is commonly known per se, it is not necessary here to give a more detailed description of its design and functioning. It is noted that different designs for the optical detector 35 are also possible. For instance, the satellite segments may be omitted, as known per se.
  • Figure IB also illustrates that the read signal input 91 of the control circuit 90 actually comprises a plurality of inputs for receiving all individual detector signals.
  • the read signal input 91 of the control circuit 90 actually comprises six inputs 91a, 91b, 91c, 9 Id, 91e, 91f for receiving said individual detector signals A, B, C, D, SI, S2, respectively.
  • the control circuit 90 is designed to process said individual detector signals A, B, C, D, SI, S2, in order to derive data signals and one or more error signals.
  • a radial error signal designated hereinafter simply as RE, indicates the radial distance between a track and the focal spot F.
  • a focus error signal indicates the axial distance between a storage layer and the focal spot F. It is noted that, depending on the design of the optical detector, different formulas for error signal calculation may be used. Generally speaking, such error signals each are a measure for a certain kind of asymmetry of the central optical spot on the detector 35, and hence are sensitive to displacement of the optical scanning spot with respect to the disc.
  • This signal is a measure for the reflectivity of the disc.
  • the usual error signals such as REn
  • REn are derived by suitably adding some of the (or all of the) individual detector signals A, B, C, D, SI, S2, at least one (but not all) of the signals being inverted (i.e. multiplied by -1), as will be known to persons skilled in the art.
  • a radial error signal REn can be defined according to (A + D) - (B + Q - WjSl - S2) A + B + C + D + SI + S2
  • the control circuit 90 is designed to generate its control signals as a function of the error signals, to reduce the corresponding error, as will be clear to a person skilled in the art.
  • the control circuit 90 has a variable control characteristic which depends on the type of error.
  • the control characteristic of the control circuit 90 is adapted according to a first strategy in order to adequately handle disc defects.
  • the control characteristic of the control circuit 90 is adapted according to a second strategy in order to adequately handle external shocks, which second strategy differs from the first strategy.
  • the exact nature of these control characteristics which are adapted is a matter of design. For instance, it is possible that a gain in the control circuit is adapted.
  • the control characteristic of the control circuit 90 contains a number of variable control parameters.
  • the setting of at least one of these variable control parameters is varied as a function of at least two detection signals, namely at least the two signals of first and second type described above, this function being such that said first strategy is reliably implemented in the case of disc defects whereas said second strategy is reliably implemented in the case of external shocks or vibrations.
  • FIG. 2 is a block diagram schematically illustrating a part of an examplary control circuit 90 in more detail.
  • this part of control circuit 90 may relate to the control of the radial actuator 51.
  • the control circuit 90 comprises a PID controller 60 having an input 61 and an output 69.
  • a radial error signal is received at input 61, and subjected to a first common amplifier 71 with variable gain kl.
  • the PID controller 60 comprises three parallel branches, i.e.
  • the P-branch 62 comprises a P-processor 65, providing a P-signal Sp to a summation point 68.
  • the I-branch 63 comprises an I-processor 66, providing an I-signal S to the summation point 68.
  • the D- branch 64 comprises a D-processor 67, providing a D-signal SD to the summation point 68.
  • the summation point output signal S+ is subjected to a second common amplifier 75 with variable gain k5.
  • At least one of said gains k, i indicating 1-5, and preferably all of said gains, are varied depending on at least two types of signals, each derived from the optical detector signal SR.
  • each gain kj can be described as a function f;(xl, x2) of two signals xl and x2, xl and x2 indicating the two types of signals, respectively.
  • the mirror signal MIRn is used as signal xl of first type, and the normalized radial error signal REn is used as signal x2 of second type.
  • the mirror signal MIRn is a measure for the reflectivity of the disc.
  • this signal has a substantially constant value, indicated hereinafter as M, which is substantially independent from shocks or vibrations, but which rapidly decreases in a case of disc defects.
  • M substantially constant value
  • MIRn another signal which is based on summation of two or more individual segment output signals might be used as a signal of first type.
  • An example of such alternative signal, suitable for use as first type signal in the context of the present invention, is CA A+B+C+D.
  • the normalized radial error signal REn is a measure for optical spot displacement in the radial direction.
  • another signal which is based on summation of two or more individual segment output signals, at least one (but not all) of those signals being multiplied by -1 might be used as a signal of second type.
  • Examples of such alternative signal, suitable for use as second type signal in the context of the present invention are: S1-S2; A-B; FEn.
  • figure 3 illustrates a possible first function fl for varying the first gain kl.
  • FIG. 3 is a graph containing a curve 80 showing gain kl (vertical axis) as a function of radial error REn (horizontal axis) for different values of MIRn. It should be clear that it is also possible to show kl as a function of MIRn (horizontal axis) for different values of REn, or to show kl as a three-dimensional graph.
  • the first gain kl has a nominal value kl,0.
  • the first gain kl is kept constant at its nominal value kl,0 (horizontal stem 83 of curve 80). If the radial error is above said threshold Rj, the first gain kl is increased (first branch 81 of curve 80) or decreased (second branch 82 of curve 80) depending on the second type input signal MIRn. If MIRn has a value indicating disc defects, the first gain kl is decreased. Otherwise, if MIRn has a value indicating shocks or vibrations, the first gain kl is increased. The amount of decrease or increase, respectively, depends on the magnitude of REn. Thus, the value of the first gain kl is selected in dependency of two signals.
  • the present invention is already embodied if the value of only one of the said gains depends on at least two signals as described above. Preferably, however, more than one of the said gains are varied on the basis of at least two signals, more preferably all of the said gains.
  • Each gain may be associated with a corresponding threshold, although preferably the threshold Rj is the same for all gains. Further, each of said gains may be set in accordance with individual functions of two (or more) signals, although preferably such function (curve 80) is the same for all gains.
  • Figure 4 is a graph illustrating the effect of the present invention in relation to the above-mentioned gain kl.
  • the lefthand part of figure 4 illustrates the case of a (periodic) vibration, for instance at 40 Hz, while the righthand part of figure 4 illustrates the case of a disc defect (a black dot).
  • Dashed curves 101 and 102 respectively, illustrate the behaviour of the radial error signal REn if all gains would be kept constant at their respective nominal values, so that the control circuit 90 would perform a linear control.
  • Curve 101 shows a sine-shaped behaviour of REn in the case of a (periodic) vibration.
  • curve 102 shows large peaks corresponding with the optical spot entering and leaving the black dot.
  • Solid line 103 illustrates the behaviour of the radial error signal REn when the present invention is applied in the case of a (periodic) vibration.
  • the radial error signal REn In an initial time interval before time tl, the radial error signal REn is below threshold R ⁇ , so that gain kl is at its nominal value kl,0 (this corresponds to stem 83 of curve 80 in figure 3).
  • the radial error signal REn rises above threshold RT, while MIRn has its nominal value M, indicated by curve 111.
  • gain kl is increased from its nominal value kl,0, in this case to reach a maximum value kljyj AX , as illustrated by curve 121.
  • the radial error signal REn rises above threshold RT, while MIRn has dropped below the switching threshold ⁇ M, indicated by curve 112.
  • gain kl is decreased from its nominal value kl,0, in this case to reach a minimum value kl M ⁇ , as illustrated by curve 122. It is true that REn still rises above threshold RT, but the maximum value reached by REn is lower than in the case of linear control (curve 102).
  • REn decreases, gain kl increases, and at time t4, when REn drops below threshold RT, gain kl reaches its nominal value kl,0 again.
  • any such control parameter is set on the basis of three or more signals.
  • the focal error signal as a third signal, indicating shocks in the Z-direction.
  • the present invention has been explained with reference to an embodiment with a six-segment optical detector. It should be clear to a person skilled in the art that detectors having different design are also possible, in which case the formulas for error signals may be different.
  • the present invention has been explained with reference to block diagrams, which illustrate functional blocks of the device according to the present invention.
  • one or more of these functional blocks may be implemented in hardware, where the function of such functional block is performed by individual hardware components, but it is also possible that one or more of these functional blocks are implemented in software, so that the function of such functional block is perfonned by one or - more program lines of a computer program or a programmable device such as a microprocessor, microcontroller, etc.

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  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Optical Recording Or Reproduction (AREA)
  • Moving Of The Head For Recording And Reproducing By Optical Means (AREA)

Abstract

L'invention concerne un procédé pour commander une unité de disque optique (1) d'un type comprenant: des moyens d'exploration (30) permettant d'explorer une piste d'enregistrement d'un disque optique (2) et de générer un signal de lecture (SR); des moyens formant actionneur (50) permettant de commander le positionnement d'au moins un élément de lecture/écriture (34) desdits moyens d'exploration (30) par rapport au disque (2); un circuit de commande (90) permettant de recevoir ledit signal de lecture (SR) et de générer au moins un signal de commande d'actionneur (SCR) sur la base d'au moins une composante dudit signal de lecture (SR), ce circuit de commande (90) présentant au moins un paramètre de commande variable. Ledit procédé comporte les étapes consistant à: dériver dudit signal de lecture (SR) au moins deux signaux (REn; MIRn) de types mutuellement différents; et modifier le réglage d'au moins un paramètre de commande variable en fonction desdits au moins deux signaux.
EP04770107A 2003-10-02 2004-09-28 Appareil du type unite de disque Withdrawn EP1671320A2 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP04770107A EP1671320A2 (fr) 2003-10-02 2004-09-28 Appareil du type unite de disque

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
EP03103662 2003-10-02
EP04770107A EP1671320A2 (fr) 2003-10-02 2004-09-28 Appareil du type unite de disque
PCT/IB2004/051891 WO2005034103A2 (fr) 2003-10-02 2004-09-28 Appareil du type unite de disque

Publications (1)

Publication Number Publication Date
EP1671320A2 true EP1671320A2 (fr) 2006-06-21

Family

ID=34400546

Family Applications (1)

Application Number Title Priority Date Filing Date
EP04770107A Withdrawn EP1671320A2 (fr) 2003-10-02 2004-09-28 Appareil du type unite de disque

Country Status (6)

Country Link
EP (1) EP1671320A2 (fr)
JP (1) JP2007507822A (fr)
KR (1) KR20060088890A (fr)
CN (1) CN1860533A (fr)
TW (1) TW200516572A (fr)
WO (1) WO2005034103A2 (fr)

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19640870A1 (de) * 1996-10-04 1998-04-09 Thomson Brandt Gmbh Aufzeichnungs- oder Wiedergabegerät für optische Informationsträger mit einem Servo-Regelkreis und Verfahren zur Fehlersignalbehandlung in einem solchen
DE19931835A1 (de) * 1999-07-09 2001-01-11 Thomson Brandt Gmbh Gerät zum Lesen oder Beschreiben optischer Aufzeichnungsträger
CN1249698C (zh) * 2001-05-03 2006-04-05 皇家菲利浦电子有限公司 光学扫描装置
JP3566701B2 (ja) * 2002-01-31 2004-09-15 株式会社東芝 光ディスク記録再生装置

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
None *

Also Published As

Publication number Publication date
JP2007507822A (ja) 2007-03-29
KR20060088890A (ko) 2006-08-07
WO2005034103A3 (fr) 2005-08-25
WO2005034103A2 (fr) 2005-04-14
TW200516572A (en) 2005-05-16
CN1860533A (zh) 2006-11-08

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