U.S. Philips Corporation

Lite-on It Corporation

Koninklijke Philips Corporation N.v.

Other

Philips & Lite-on Digital Solutions Corporation

Philips & Du Pont Optical Company

Johannes Leopoldus Bakx

Maarten Kuijper

Petrus Antonius Verbeek

Antoon Dekker

Pierre Hermanus Woerlee

Tony Petrus Van Endert

Hubert Cecile Francois Martens

Johannes H Spruit

Cornelius Antonius Hezemans

Wilhelmus Robert Koppers

Jacob M Van Nieuwland

Johannes Franciscus Petrus Claas

Petrus C Hoeven

Jeroen J Horikx

Hindrik Veldhuis

Stefan Geusens

Edwin Johannes Maria Janssen

Hilde M Overath

Heemskerk: Jacobus P J

Jan J Janse

Gary Christopher Maul

Jean Phillippe Van Damme

A method for monitoring an optical disk drive performance quality by determining a laser diode quality indicator for a laser diode arranged in an optical disk drive for scanning an optical disk, includes measuring an actual value of a parameter associated with a laser diode characteristic, obtaining a reference value of the parameter, comparing the actual value with the reference value for obtaining a comparison result, and determining the laser diode quality indicator from the comparison result. The laser diode quality indicator can at least take a warning level signaling a precursor for a defective state of the optical disk drive and an error level signaling a defective state of the optical disk drive. The laser diode characteristic may be a light-current or a voltage-current relationship.

Method for monitoring an optical disk drive performance quality, optical disk drive, optical disk duplicator system and computer program product

An optical scanning device is adapted for scanning a record carrier having an outer face. The optical scanning device comprises a radiation source for generating a radiation beam, and an objective system having an exit face arranged for evanescent coupling of the radiation beam between the exit face and the outer face and for converging the radiation beam to a focus. A gap servo maintains a distance between the exit face and the outer face at a predetermined gap height. The optical scanning device includes a control unit for setting the predetermined gap height at at least two different values.

Optical scanning device and method for scanning

Recordable DVD+R and DVD+R/W optical discs with two (or more) information layers are developed to double the data storage capacity and video recording time. A method and device are proposed to make dual layer DVD disc recordings compliant with the dual layer DVD-ROM standard Recording the data in a DVD-ROM compliant way on the dual layer DVD+R or DVD+R/W disc is obtained by shifting the middle zone area towards the inner radius of a disc in such a way that the data zones of both layers are filled up with data.

Method of recording information on a multilayer record carrier, and device for recording on a dual layer record carrier

An optical disk drive for determining a disk characteristic of an optical disk comprising an information layer comprising a substantially circular track is described. The optical disk drive has an optical pickup unit arranged to generate a beam, direct the beam to the optical disk for forming an incident beam, sense a reflected beam produced by the optical disk with a sensor upon receiving the incident beam with the sensor, produce a sensor output signal from sensing the reflected beam; a disk receiving device arranged to receive the optical disk; a motor arranged to provide a transition of the disk receiving device from a first mode to a second mode in at least one transition phase; and a controller arranged to receive the sensor output signal during at least one part of the at least one transition phase and perform at least part of determining the disk characteristic from at least the sensor output signal received during the at least one part of the at least one transition phase. The transition phase can be associated with moving the optical disk into the optical disk drive with a disk load motor. The transition phase can be associated with changing a rotational speed of the optical disk with a spindle motor. Determining the disk characteristic can include a disk recognition preparation.

Optical disk drive and method for use with an optical disk drive for determining the disk characteristic

An optical disk drive and a method for scanning an optical disk that includes a substantially circular track with a scanning velocity is provided. A servo control signal (SCS) is determined based on a servo error signal (SES). A first performance indicator (IND) of the servo actuator is determined from at least one of the SES and SCS. INDis compared against a first pre-determined threshold (ITHR), determining a first servo margin (MAR). The scanning velocity is set in dependence on at least MAR. In particular, scanning velocity is reduced when the first performance indicator exceeds the first pre-determined threshold. Additionally or alternatively, a bandwidth of control of the servo actuator can be adjusted in dependence on at least one of a second servo margin, determined from at least one of SES and SCS, and a third servo margin, associated with a mark quality determined from a central aperture signal.

Optical disk drive for scanning an optical disk with a scanning velocity and method for scanning an optical disk with a scanning velocity

The optical scanning device [] is arranged for scanning a record carrier []. The record carrier has an outer face []. The scanning device comprises a radiation source [] for generating a radiation beam [] and an objective system [] having an exit face [] arranged for evanescent coupling of the radiation beam between the exit face and the outer face and for converging the radiation beam to a focus []. A tilt measuring system [] provides a tilt signal [] representing a tilt angle between the objective system and the record carrier. A control unit [] determines a distance signal representing a distance between the exit face and the focus from the tilt signal.

Optical scanning device and method for determining focus position

A method of reducing power dissipation in a variable-gain photo-detector circuit is described. The variable-gain photo-detector circuit has an output to output a main spot signal and at least one side spot signal. The main spot (M) and the side spot (Si or S) are formed by separating a light beam into a main beam and at least one side beam and focusing the main beam on the main spot (M) and the side beam on at least one side spot (Si or S) on an optical record carrier The method processes the main spot signal with a first averaging circuit having a first cut-off frequency. The side spot signal is processed with a second averaging circuit having a second cut-off frequency. The second cut-off frequency is lower than the first cut-off frequency. The above technique reduces power dissipation in the variable-gain photo-detector circuit and is useful for all optical devices.

Disc drive and photo-detector circuits

A method for estimating maximum available write power of an optical storage drive includes generating a beam of laser light having a power level, measuring a first parameter of the laser light source and a second parameter of the beam of laser light, and using the measured parameters to estimate the maximum available write power.

Estimation of maximum available write power of an optical storage drive

An optical disk drive and a method for determining a disk type are described. The optical disk drive may be arranged to receive a radial error signal while an incident beam is focused onto the optical disk and before tracking the track, to analyze the radial error signal for detecting whether a wobble signal is present, indicating whether the track is wobbled, and to derive a disk type from the wobble signal, if present. The optical disk drive may additionally or alternatively be arranged to receive a central aperture signal while the incident beam is focused onto the optical disk and before tracking a track including a sequence of embossed pits, to analyze the signal amplitude of the central aperture signal, and to determine the disk type from at least a first variation of the signal amplitude of the central aperture signal as a function of time.

Optical disk drive with disk type determination and method of determining a disk type of an optical disk with an optical disk drive

In a tracking control method for use in an optical disk drive to read/write an optical disk, an open-loop tracking control operation of the optical disk drive is first performed according to an input tracking error signal and a predetermined periodical offset to generate a dynamic offset. Afterwards, a closed-loop tracking control operation of the optical disk drive is performed according to the input tracking error signal calibrated with the dynamic offset.

Tracking control method for reading/writing optical disk

Because of the reduced track pitch of DVD compared to that of CD, the running-OPC procedures (ROPC) currently used in CD-RW systems do not function well in recordable and rewritable DVD systems. The present invention proposes to use the reflected signal from the writing spot itself instead of the satellite spots used in the CD-RW running-OPC procedure. This is realized by sampling the RF-signal reflected from the writing spot at the high-reflective crystalline level. This sampled signal (&#x3b1;) is fed into a power control loop (a so-called &#x3b1;-loop) to keep it at a constant level.

Method and device for running optimum power control

An optical writing and/or reading device. A radiation source (10) generates a radiation beam (11). This radiation beam (11) is directed by an optical system onto a servotrack (4) of a rotating record carrier (1). The beam reflected via the record carrier is passed on to a push-pull detector (12). The servotrack has a periodical radial wobble whose frequency is modulated in accordance with a position-information signal. A signal-regaining circuit (17) regains the position-information signal from the push-pull signal. A balancing circuit (41, 42; 50, 51) adjusts a weighting the ratio between the detection signals which contribute to the difference signal. The DC component in the adapted push-pull signal is derived by means of a low-pass filter (44). In dependence upon the determined DC component, a circuit (45) sets the weighting ratio to a value at which the determined DC component is substantially zero.

Optical storage disc scanner with improved scanner positioning

An apparatus and method for recording an information signal on a record carrier by means of a radiation beam which produces optically detectable marks in parallel track portions thereon having a substantially constant track pitch (q). The write intensity of the radiation beam is adjusted to an optimum level which results in a width (p) of the optical marks which corresponds to the track pitch (q). The optimum intensity level is determined by recording different test signals in adjoining track portions at various write intensities of the radiation beam, reading-out the recorded test signals, and detecting therefrom the write intensity at which signal components of one test signal no longer occur in another recorded test signal. Recording at the optimum write intensity results in a minimum block error rate (BLER) upon read-out of the recorded information signal.

Method and apparatus for recording signals on a record carrier,

A method and device for recording signals on a record carrier with the aid of a radiation beam (15). The signals are recorded in the form of optically detectable marks in parallel tracks which have a substantially constant track pitch. The recording intensity of the radiation beam is set in such a way that with a 'minimum' recording intensity information patterns are recorded with a low desired error rate '(Block) Error Rate'. Furthermore, a method and device are described by which the 'minimum' recording intensity of the radiation beam can be determined.

Methods and devices for recording one or more signals which have been

An information recording device for recording digital information at a higher bit rate than that at which it is received. The difference in bit rate is compensated by an input buffer memory, read-out of a packet of information stored therein and recording thereof being periodically interrupted so as to maintain the filling level within a predetermined range. During each recording interruption, the recorded information pattern corresponding to the last recorded packet of information is read-out from the record carrier and the read-out signal is analyzed by an analysis circuit to derive an indication signal indicative of recording quality. The indication signal can be used to optimize the write parameters of the recording device, and also to determine whether re-recording of any or all of the last already recorded information packet should be performed before resuming read-out and recording of subsequent information packets from the buffer memory.

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Eindhoven, Netherlands

Johannes Leopoldus Bakx