Koninklijke Philips Corporation N.v.

Jeroen Arnoldus Leonardus Johannes Raaymakers

Herman Van Der Kall

George Alois Leonie Leenknegt

Stefan Geusens

Igolt Pieter Douwes Ubbens

Mohamad-Hussein El Husseini

Stefan Hendrik Guillaume Steven

Jan Verbiest

A method and a device for fast disc recognition for use in read/write performances when an optical disc is connected to an optical drive, including the provision of a set S of parameters for safe data transfer between the drive and the disc, the direct calibration during a disc recognition step only of those parameters out of said set S in need of a direct calibration, the start of a read/write data transfer sequence after said disc recognition step is finalized and the calibration of the remaining parameters at first after or during one or more data transfer read/write sequences.

Fast disc recognition by elimination of calibrations

The present invention relates to a method for operating an optical drive system () capable of reproducing/recording information from/to an optical carrier (), wherein the optical drive system includes a focus controller (PID) for controlling a focus actuator (), and a focus memory loop (ML) for applying a stored correction signal to the focus actuator (). The method aims at avoiding impacts between the focussing means () and the optical carrier (), by gradually stopping the focus control loop in response to an event, such as a user initiated ejection of the optical carrier. The gradual stop of the focus control loop is achieved by gradually reducing a memory loop parameter of the focus memory loop (ML), and by gradually reducing a controller parameter of an integrating part (I) of the focus controller (PID). It is an advantage of the invention that the phase of the stored correction signal is synchronized with the angular position of optical carrier () during the gradual stopping.

Method for gradually closing down a focus control loop of an optical drive system

A device is for scribing a visible label on the medium includes a head for providing a beam and generating a detector signal in dependence of radiation reflected from the medium, and a focus unit or generating a focus control signal for focusing the beam. A label control unit controls the scribing in dependence of label data. The focus unit detects a focus error by including a focus excitation signal in the focus control signal and detecting a deviation in the detector signal in dependence of the focus excitation signal. The label control unit is for controlling the focus unit in dependence on the label data to detect the focus error during said scribing and without interrupting said scribing.

System for scribing a visible label

In a method and device for performing tilt control, a focus and a tilt controlling output is generated, and a focusing and tilt state of an optical recording/reproducing beam is controlled by determining a radial tilt value based on a differentiation of focus control values obtained at different radii of said optical disk (). The combination of, e.g., a 3D actuator with the dz/dr tilt measurement provides the advantage that focus and tilt adjustment can be performed in the same element. Thereby, influences or measurement variations caused by environmental conditions and/or circuit characteristics can be minimized to reduce compensations requirements. Furthermore, a 3D actuator () with a split coil arrangement may be used to provide a three-dimensional focus adjustment. Thereby, the 3D actuator () can be used for feed-forward tilt compensation without offset or gain errors and without any additional sensor.

Method and device for performing tilt correction using multi-dimensional actuator

The present invention relates to a method for operating an optical drive system capable of reproducing/recording information from/to an optical carrier (), wherein a position error and a speed error of a radiation spot () on the carrier has been created due to an unreliable error signal which has been generated due to a surface defect (). The method includes the steps of registering values of e.g. servo signals, determining the occurrence of a defect using a defect detector DEFO (), generating a first and a second compensation signal and applying these compensation signals to the control system () of the optical drive system. The first compensation signal is capable of reducing the speed error and the second compensation signal is capable of reducing the position error. Thus, the application of the compensation signals immediately after the unreliable error signals reduces the position error and the speed error of the focussed radiation spot ().

Optimum tracking error compensation for improved optical disk playability

A device is for scribing a visible label on the medium. The medium (), for example an optical disc, has a label side provided with a radiation sensitive layer for creating the visible label via a beam of radiation. The device has a head () and a positioning unit () for radially positioning a scribing spot, which unit has a course positioning system by movements of the head and a fine positioning system. The device has a generator unit () for, during at least one boundary trace of the substantially parallel traces which precedes or succeeds a head movement, temporarily applying a broadening signal () to the fine positioning system for broadening the boundary trace in the transverse direction. This has the advantage that unwritten annular areas called white bands, which may occur due to mismatch of the head movement and the fine positioning system, are reduced or prevented.

An apparatus for scanning a track on a record carrier has a head for scanning the track and generating a read signal. The tilt between the head and the record carrier () is compensated via a tilt servo loop. Thereto the head is provided with tilt compensating actuators (). A measure of the tilt is jitter in the read signal generated by a front end () and filter (). A wobble generator () provides a wobble signal to the actuators and to an input of multiplier () for synchronous detection of the jitter. The output of the multiplier () is coupled to a low pass filter () for generating a tilt error signal coupled to a tilt controller () for generating a tilt control signal.

Tilt control for reading information

An optical playback or recording device is equipped with mass-unbalance detection means () for detecting unbalance on the record carrier (). Mass-unbalance causes vibration and sound in the optical device when the record carrier () is rotated at a relatively high speed. When mass-unbalance is detected, the speed may be reduced to reduce the vibration and sound in the optical device. The mass-unbalance detection means () performs the following steps to detect mass-unbalance: a) determining the maximum value Uof the actuator control signal (AS) at a rotational speed &#x3a9;; b) determining the maximum value Uof the actuator control signal (AS) at a rotational speed &#x3a9;; c) comparing Formula (I) with Formula (II). If these values are substantially equal, then the effect of mass-unbalance is small, otherwise the effect of mass-unbalance is too great and the speed may have to be reduced 

Optical device for reading information

The present invention relates to a tilt control device and method for an optical disc player, wherein an output offset of a tilt detecting means () is calibrated by using an output of a focus controller (). Since the offset is calibrated based on the focus controlling output, the calibration can be performed for all written and non-written discs. As an alternative, a tilt control with high accuracy can be performed by adjusting a tilt frame based on at least two measurements of the controlling output of said focus control means at different radial positions. Thereby, the disc can be positioned in a radial tilt zero position with the aid of the focus controlling output. Now, the tilt detecting means is no longer required for tilt adjustment.

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Eindhoven, Netherlands

Jeroen Arnoldus Leonardus Johannes Raaymakers