Koninklijke Philips Corporation N.v.

Herman Van Der Kall

Jeroen Arnoldus Leonardus Johannes Raaymakers

Joop Van Bijnen

Robertus Josephus Maria Verhoeven

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

An optical disc device comprising a tray () for carrying an optical disc, which tray () can move between a position inside the device and a position partly outside the device. The device also comprises a structure () for holding and driving the optical disc, which structure () is provided with a turntable () and an optical pickup unit () and guiding means for moving the optical pickup unit (). The structure () can tilt around a horizontal tilt axis () behind the rotating optical disc. The tray () is provided with a catch member () and the optical pickup unit () is provided with a cooperating catch surface (), whereby the catch member () may hit the catch surface () when the tray () moves, thereby displacing the optical pickup unit () into a save position.

Optical disc device protecting the optical pickup unit during ejection by a catch member of a tray displacing a catch surface of the optical pickup unit

In an optical disc drive, adapted for forming a label on the label sideof a recordable optical disc, a determination of the rotation angle a is provided, so that the marking of the label sidecan be synchronized upon. The method to determine the rotation angle a is based upon one or two of the signals' generated by the Hall-effect elementswhich are normally present in an optical disc drive and are used to generate the tacho signal. Advantageously, the actual relationship between rotation angle a and the amplitude of these signals is recorded in a calibration procedure, so as to allow for a higher precision of the rotation angle a determined. This calibration procedure may be performed in the factory or by the user, and may not require any additional ad-hoc equipment if a synchronization pattern present in an optical disc is used.

Method and apparatus for forming a label

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

In a device () for reading and/or writing information from and on, a track on a medium (), a read and/or write head () can be positioned with a positioning device () relative to the medium (). The read and/or write head () comprises a carriage () and means () for maintaining the reading and/or writing in a scanning point at the track during a transverse positioning of the track relative to the carriage (). A control circuit () is present for controlling the positioning device (). There is a period of the order to magnitude of one millisecond between the supplying of a control signal to the positioning device () at a first point in time based upon which the read and/or write head () has to be positioned and the actual start of the movement of the read and/or write head (). The first point in time is before the point in time at which the maintaining means () reach the end of the track that is being read or written at the first point in time. The carriage () already moves at a certain velocity and has already been moved over a certain distance (D) when the maintaining means () reach the end of the track which is read or written.

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Eindhoven, Netherlands

Herman Van Der Kall