Abstract: When an optical recording medium having a plurality of data layers is being read from and/or written to, the input beam experiences an aberration, inter alia in the top layers of the data layers. In order, nevertheless, to achieve a high data density, a device for correcting the spherical aberration is located in the beam path of the input beam. In the case of the use of an optical diode in which the input beam and the reflected beam have directions of polarization perpendicular to one another, such a device is expensive to implement and associated with a reduced optical efficiency. It is an object of the invention to propose an apparatus for reading from and/or writing to optical recording media, in the case of which a high optical efficiency and balancing of the spherical aberration are achieved with low outlay.

Abstract: The device comprises directing means for directing a first and a second light beam onto a hologram area of the optical data carrier, wherein the first and second light beams are coherent light beams. The directing means are adapted to direct the first light beam onto the hologram area along a first direction, and the second light beam onto the hologram area along a second direction. Tilting means are provided for tilting the second direction by a predefined tilt angle with respect to the first direction.

Abstract: Method for recording on an optical recording medium The invention relates to a method for recording on an optical recording medium, to an optical recording medium suitable for this method, and to a device for writing to optical recording media using such method or optical recording medium. According to the invention the recording process is split into two tasks: Pre-writing an optical recording medium, e.g. in a stationary device, and recording on the optical recording medium with a low-power write strategy, e.g. in a mobile device.

Abstract: Device and method for reading multilayer optical disk The invention refers to a device and a method for scanning an optical data carrier (1) by means of a main scanning beam (3) being reflected by the data carrier (1) and being detected by means of a photodetector (10), the data carrier (1) having first and second layers (11,12) to be scanned, the second layer (12) being scanned through the first layer (11), light passing the first layer (11) being shaded dependent on local properties of the first layer (11). An object of the invention is to propose a device having increased performance even for use with multi layer disks (1) having a layer (11) causing light fluctuations on a layer (12) to be scanned, as well as a respective method. According to the invention such device is provided with means (2,7,17) for keeping an output signal (D) of the photodetector (10) independent of variations of shading.

Abstract: The invention refers to a device and a method for scanning an optical data carrier by means of a main scanning beam being reflected by the data carrier and being detected by means of a photodetector, the data carrier having first and second layers to be scanned, the second layer being scanned through the first layer, light passing the first layer being shaded dependent on local properties of the first layer. An object of the invention is to propose a device having increased performance even for use with multi layer disks having a layer causing light fluctuations on a layer to be scanned, as well as a respective method. According to the invention such device is provided with means for keeping an output signal of the photodetector independent of variations of shading.

Abstract: The invention relates to an optical pickup for an optical recording medium, an electrically controlled diffraction grating suitable for use in such a pickup, and to an apparatus for reading from and/or writing to optical recording media using such an optical pickup or diffraction grating. According to the invention, an optical pickup for optical recording media having two or more data tracks, with a light source for emitting a light beam for reading from and/or writing to an optical recording medium, includes an electrically controlled diffraction grating, which is switchable between at least two states for generating one or more light beams from the light beam emitted by the light source for reading from and/or writing to one or more of the data tracks.

Abstract: The present invention relates to an optical recording medium having at least two information carrier layers, on which information can be written by means of a focused light beam. In this case, a separating layer is arranged between the information carrier layers and a respective transparent covering layer is arranged between the information carrier layer and the surface of the recording medium, the thickness of which covering layer substantially exceeds that of the information carrier layer. One object of the present invention is to propose an optical recording medium in the case of which it is possible to write to both information carrier layers using a low optical power. Further objects of the invention are to specify an apparatus and also a suitable method for writing to a recording medium of this type. A recording medium according to the invention has information carrier layers which are both semi-transparent.

Abstract: When an optical recording medium having a plurality of data layers is being read from and/or written to, the input beam experiences an aberration, inter alia in the top layers of the data layers. In order, nevertheless, to achieve a high data density, a device for correcting the spherical aberration is located in the beam path of the input beam. In the case of the use of an optical diode in which the input beam and the reflected beam have directions of polarization perpendicular to one another, such a device is expensive to implement and associated with a reduced optical efficiency. It is an object of the invention to propose an apparatus for reading from and/or writing to optical recording media, in the case of which a high optical efficiency and balancing of the spherical aberration are achieved with low outlay.

Abstract: An optical recording medium having at least two information carrier layers, on which information can be written by means of a focused light beam. In the present invention, a separating layer is arranged between the information carrier layers and a respective transparent covering layer is arranged between the information carrier layer and the surface of the recording medium, the thickness of each transparent covering layer substantially exceeds that of the respective information carrier layer. One object of the present invention is to propose an optical recording medium in the which it is possible to write to both information carrier layers using a low optical power. Further objects of the invention are to specify an apparatus and also a suitable method for writing to recording medium according to the present invention. A recording medium according to the invention has information carrier layers which are both semi-transparent.

Abstract: The present invention relates to a holographic disk medium (1) with servo marks (7), and more specifically to a holographic disk medium (1) having a common reflective layer (3) for reflecting a servo beam (9) and object and reference beams (8). According to the invention, a holographic disk medium (1) with a recording layer (2) for recording holograms (6) and a reflective layer (3) for reflecting a servo beam (9) and object and reference beams (8), includes servo marks (7) which are located in the reflective layer (3) at least partly below the holograms (6), wherein the servo marks (7) are designed such that their influence on the object and reference beams (8) is minimized.

Abstract: An apparatus for recording angular multiplexed pits on optical recording media using a device for generating a light beam with an asymmetric intensity distribution is described. The device for generating a light beam with an asymmetric intensity distribution has at least one light influencing part for introducing a phase shift of 180° in a first half of the light beam relative to the second half of the light beam, wherein the border between the first half of the light beam and the second half of the light beam is rotatable around an optical axis of the light beam.

Abstract: Described are a novel marker protein associated with apithelial tumors, TAP-70, belonging to the family of aspartyl proteinases and nucleic acid molecules encoding TAP-70 polypeptides. Moreover, diagnostic and therapeutic uses based on the finding that TAP-70 is overexpressed throughout skin carcinogenesis are described.

Abstract: The invention relates to a method for storing data in a prerecorded area of an optical recording medium, and to an optical recording medium having at least one prerecorded area in which data is stored according to the method. It is an object to propose a method for storing data in a prerecorded area of an optical recording medium using pits and lands, whereby the signal obtained from the pits and lands is compatible with a high frequency modulated groove signal. According to the invention, the pits and lands adjacent to bit cell signal transitions are arranged in a predefined manner, either in a fixed recurring sequence of pits and lands or symmetrically to the bit cell signal transitions.

Abstract: An optical detection device for detecting an intensity of a light beam in a detection window and for detecting data transmitted by the light beam includes a first detection diode and an array of at least two second detection diodes in a detection window. In addition, provision is made for a first readout circuit connectable to the first detection diode, for reading out the first detection diode at a first readout speed to detect the data, and for a second readout circuit connectable to the second detection diodes, for reading out the second detection diodes at a second readout speed smaller than the first readout speed, so as to detect the intensity of the light beam.

Abstract: An optical detection device for detecting an intensity of a light beam in a detection window and for detecting data transmitted by the light beam includes a first detection diode and an array of at least two second detection diodes in a detection window. In addition, provision is made for a first readout circuit connectable to the first detection diode, for reading out the first detection diode at a first readout speed to detect the data, and for a second readout circuit connectable to the second detection diodes, for reading out the second detection diodes at a second readout speed smaller than the first readout speed, so as to detect the intensity of the light beam.

Abstract: The invention refers to a device and a method for scanning an optical data carrier (1) by means of a main scanning beam (3) being reflected by the data carrier (1) and being detected by means of a photodetector (10), the data carrier (1) having first and second layers (11,12) to be scanned, the second layer (12) being scanned through the first layer (11), light passing the first layer (11) being shaded dependent on local properties of the first layer (11). An object of the invention is to propose a device having increased performance even for use with multi layer disks (1) having a layer (11) causing light fluctuations on a layer (12) to be scanned, as well as a respective method. According to the invention such device is provided with means (2,7,17) for keeping an output signal (D) of the photodetector (10) independent of variations of shading.

Abstract: The present invention relates to an appliance for reading from and/or writing to optical recording media 1 having a first laser diode LD1 for producing a first scanning beam AS1 at a first wavelength &lgr;1 and having a second laser diode LD2 for producing a second scanning beam AS2 at a second wavelength &lgr;2, with the scanning beams AS1, AS2 running along a common optical axis 9, scanning an information layer 6 on the recording medium 1 and falling on a single photodetector 8 in order to produce an information signal IS, with a beam combination element being arranged at one point on the optical axis 9. According to the invention, the beam combination element is a diffraction grating 12.

Abstract: An apparatus for simultaneously reading from or writing to different information carrier layers of an optical recording medium having at least two different information carrier layers, the apparatus comprising partial beam generating means for generating different partial beams, focusing means for focusing the partial beams onto different information carrier layers and detection means for detecting the partial beams. The present invention provides a largely common optical path for the individual partial beams and is nevertheless tolerant with regard to deviations in the spacing of individual information carrier layers from one another. This object is achieved by virtue of the fact that a partial beam generating means is provided for coupling out a partial beam and a beam influencing means is provided for independently influencing the coupled-out partial beam.

Abstract: The present invention relates to a device for reading from or writing to optical recording media, which device has a scanning beam generation means, a focusing means and a photodetector comprising at least two detector zones and serving to receive zeroth- and first-order diffraction beams from the recording medium. The object of the invention is to obtain a reduction in interfering influences in a signal derived from signals of the photodetector, a signal such as, for example, a focus error signal or a track error signal. This object is achieved by virtue of the fact that a beam splitting means is provided, which splits a light spot falling onto the photodetector into two separate partial spots. The device is, for example, a CD or DVD player, but in particular a recording and reproduction device for so-called DVD-RAMs or similar optical recording media.

Abstract: The present invention relates to an apparatus for simultaneously reading from or writing to different information carrier layers of an optical recording medium having at least two different information carrier layers, the apparatus having partial beam generating means for generating different partial beams, focusing means for focusing the partial beams onto different information carrier layers and detection means for detecting the partial beams.