Abstract: The present invention relates to an optical storage medium (20) comprising a first data area (21) for storing content and a second data area (23) for storing limitation data (24) for limiting access to at least a portion of the first data area. It is desired that the period of time for which access to content stored on the storage medium is limited, such that, for instance, after said period of time unlimited access to said content is granted. To achieve this a state change means (27) is provided on the storage medium, adapted for changing its optical reflectivity and/or transmittance over time, said change directly preventing access to the second data area after a limited period of time or being indirectly used to decide whether access to the at least one portion of the first data area shall be limited according to said limitation data.

Abstract: In a magneto optical device is which a laser beam is shone in operation through a coil (5), the coil holder (6) comprises a concavely curved exit surface with a radius of curvature R lying between 0.5 D and 15 D (0.5 D?R?15 D) where D is the diameter of the concavely shaped exit surface.

Abstract: A method of recording information onto an optical disc of the rewritable type, the disc comprising a spiral track, at least part of the track being arranged as a recording area for recording the information, the recording area being further divided into sequential, independently addressable units of pre-determined size, pre-determined numbers of addressable units being grouped in recording unit blocks comprising: deciding for at least an recording unit block that it will be recorded; determining direct overwrite information for said recording unit block, the direct overwrite information comprising information with respect to the number of times the recording unit block was previously recorded; encoding and recording the information into the recording unit block and updating the direct overwrite information for the recording unit block, the direct overwrite information being recorded within the recording unit block.

Abstract: The present invention relates to an optical drive (10) suitable to write optical storage discs and comprising means for accessing at least one central database (14) which may be accessed by a plurality of optical drives to derive write strategy information assigned to known disc types. In accordance with the present invention the optical drive (10) is adapted to provide said central database (14) with at least a part of disc type identification information obtained from an inserted disc (16), if said inserted disc (16) is of an unknown disc type. Furthermore, the present invention relates to a method for determining the write strategy of an optical drive (10).

Abstract: A magnetic head for a magneto-optical device comprises a plurality of substantially parallel planar layers, including at least one layer comprising a coil formed by a plurality of turns an electrically conductive winding, the turns lying substantially in a plane defined by the layer and the winding being substantially centered on a central axis perpendicular to the plane, and further including a yoke layer comprised of an anisotropic flux guiding material. The yoke layer comprises a plurality of segments (16) of flux guiding material dividing the yoke layer into sectors that together surround the central axis. In each sector, the flux guiding material has an easy axis in a plane of the yoke layer with a direction different from the direction of the easy axis in an adjacent sector.

Abstract: Method of manufacturing a magneto-optical device, wherein at least one coil (3) is embedded in an oxide layer (2), wherein the oxide layer (2) is provided with at least one aperture (4). Wherein said aperture (4) is etched selectively in said oxide layer (2) with the use of a sloping side wall (6) of at least one turn (6) of said coil (3).

Abstract: The present invention relates to a method of writing information on an optical recording medium (10 to 38), the optical recording medium having at least one data layer (40) for storing data readable by use of an optical readout device and at least one label layer (42) for storing visible information, the method comprising the steps of: focusing a first wavelength laser beam (44 to 58) onto the at least one data layer for writing data on the data layer, and focusing a second wavelength laser beam (60 to 78) onto the at least one label layer for writing visible information on the label layer, thereby a laser spot size being usable that is also employable when using the second wavelength laser beam for writing data on a data layer for storing data readable by use of an optical readout device. The present invention further relates to an optical recording medium and to a method of manufacturing an optical recording medium.

Abstract: Method of controlling a current through a coil (L) for the generation of a magnetic field (H) in which: a parameter is determined which is a measure for the value of the resistance (RL) of the coil (L), the current (IL) through the coil (L) is controlled by data (DS) delivered by a data control circuit (DSS), and a stop data signal (SPD) is delivered to the data control circuit (DSS) for (at least) temporarily stopping the control of the current (IL) when the parameter exceeds a certain limit.

Abstract: An electronic circuit comprising means (CMNS) for controlling a current (IL) through a coil (L) for the generation of a magnetic field (H). The means (CMNS) comprise means (DMNS) for the determination of a parameter which is a measure for the value of the resistance (RL) of the coil (L). During operation the maximum absolute value of the current (IL) is decreased when the parameter exceeds a certain limit.