Abstract: 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.

Abstract: An apparatus generates outgoing data (OD) to be provided on an optical disk (1) in a burst cutting area (2). The burst cutting area (2) further comprises markings (3) which cause a marking frequency spectrum (MFS) when reading out the burst cutting area (2). The apparatus comprises a channel coder (4) which receives processed data (PD) and supplies the outgoing data (OD) having an outgoing data frequency spectrum (DFS) with suppressed DC-content. The apparatus further comprises a data processing device (5) which generates the processed data (PD) to obtain an outgoing frequency spectrum (DFS) wherein a frequency component causing interference with a low frequent component of the markings (3) is suppressed or not present.

Abstract: The invention relates to an optical disk drive. The optical disk drive has an objective lens to be driven by a focus actuator with a focus offset for focusing an incident beam onto an optical disk into a spot with a spherical aberration, and a processor to derive a first and a second characteristic from a sensor output signal and obtain a spherical aberration correction value (SA) from a pre-determined function, the pre-determined function defining a spherical aberration correction value in dependence on a focus offset difference value (?FO). The focus offset difference value (?FO) is determined from a difference between a second optimal focus offset at which the second characteristic is optimal and a first optimal focus offset at which the first characteristic is optimal. The spherical aberration correction value (SA) can be used to achieve a correction to the spherical aberration of the spot.

Abstract: The invention relates to a method for setting an optimum value of a write parameter for use in an optical recording apparatus for writing information on an optical recording medium by means of a radiation beam. The optimum value of a write parameter is found by curve-fitting a function and obtaining a characteristic write power level (PChar) from the curve-fitting function. It is then assessed if the characteristic write power level (PChar) qualify as an optimum value of a write parameter. If the characteristic write power level (Pchar) does not qualify as an optimum value of a write parameter then an iteration procedure is started, where the subsequent initial values of write power level (Pini, n), are given by Pini, n+1=A Pini, n+(1?A)Pchar, n, where A is a constant, and n is an integer. The invention also relates to an optical recording apparatus and an optical recording medium according to the invention.

Abstract: The invention relates to a method for determining write strategy parameter values for writing data on an optical disk from a group of optical disks of different types using an optical disk drive, in particular to different types of BD disks. The method includes identifying the type of optical disk, the type of optical disk being associated with a standard write strategy with standard write strategy parameters; determining a cluster write strategy with cluster write strategy parameters, the number of cluster write strategy parameters being smaller than the number of standard write strategy parameters; initializing the cluster write strategy parameters with initial cluster write strategy parameter values; and optimizing cluster write strategy parameter values for at least a subset of the cluster write strategy parameters. The optimizing is preferably performed on optimization sets of cluster write strategy parameters in a pre-determined optimization order.

Abstract: A method and system for obtaining focus optimization in an optical disc system is disclosed. The focus offset of a recording unit is set to a first of a plurality of predetermined values. A HF quality value is measured and stored for the selected focus offset value of the recording unit. The focus offset is then set to a best-known focus offset value. Tracks on the optical media being read are then jumped. The above steps are then repeated for each of the plurality of predetermined focus offset values. The optimal focus setting is then determined from the stored HF quality measurements.

Abstract: The present invention relates to a drive for accessing an optical record carrier (2) comprising means (4) for determining the type of record carrier, in particular for distinguishing a read-only record carrier from a recordable or rewritable record carrier having a wobbled groove in the lead-in zone, said means comprising: a DPD measuring unit (41) for measuring the differential phase detection (DPD) signal, a PP measuring unit (42) for measuring the push-pull (PP) signal in case no DPD signal could be measured, a wobble locking unit (43) for locking, in case a PP signal could be measured, to the wobble embedded in said wobbled groove using a first and/or a second polarity setting, and an indication unit (44) for generating a first indication signal indicating that the record carrier is a read-only record carrier if a DPD signal could be measured and that the record carrier is a recordable or rewritable record carrier if no DPD signal but a PP signal could be measured and if locking to the wobble has been suc

Abstract: The present invention relates to a method of performing a writing power calibration for optical recording on an optical storage medium having a spiral track structure, comprising the steps of: selecting a first partition (10) on the track structure having a first track (12) and an adjacent second track (14) that do both not contain written information on track portions (16, 18) within the first partition (10), wherein the second track (14) may be neighboured by a third track (20) that may have a track portion (22) within the first partition (10) containing written information, writing to the track portion (16) of the first track (12) within the first partition (10) using a predetermined writing power profile of a laser beam, reading information written to the first track (12) within the first partition (10), and determining a relation between an asymmetry value and laser power on the basis of the writing power profile and the information read from the first track (12).

Abstract: A method, an optical record carrier and an apparatus for writing information to an optical record carrier include reading a write strategy from the optical record carrier which has at least two write strategies, and forming pits and lands by controlling a radiation source with the read write strategy. The method further includes determining which of the at least two write strategies is the most optimal one by reading an indication present on the optical record carrier. The most optimal write strategy is used to form the pits and the lands. If an apparatus for writing information to an optical record carrier is capable of applying two or more write strategies stored on the optical record carrier, then the apparatus reads the indication and applies the write strategy which is the most optimal one.

Abstract: A method of applying image data as a visually detectable pattern with at least one embedded data element at an optical record carrier is disclosed, comprising the step of physically mapping at least one channel symbol onto the record carrier, the channel symbol being selected from a set of mutually different channel symbols, the channel symbols each comprising an area of size s1 with a relatively low value v1 for an optical property and an area with size s2 with a relatively high value v2 for said optical property, the channel symbols being distributed over a plurality of subsets each having a plurality of channel symbols wherein the plurality of channel symbols within a subset have a distance that is substantially less than the distance between channel symbols of mutually different subsets, wherein the distance between two channel symbols is defined as the absolute difference between the ratios s1/(s1+s2).

Abstract: A method is disclosed of reading an image data from an optical record carrier with a visually detectable pattern comprising a visually detectable pattern of pixels comprising at least one pattern element comprising an area of size s1 with a relatively low value v1 for an optical property and an area with size s2 with a relatively high value v2 for said optical property, wherein the data representative for a structure of the visually detectable pattern is embedded by variations in one or more of the parameters s1, v1, s2, v2 of the pattern elements. The method comprising the steps of scanning the visually detectable pattern and generating a detection signal representative for a visual property of the pattern as a function of position, retrieving the image data from the signal, retrieving an embedded data from the signal, generating an address data using said embedded data, storing image data values at addresses indicated by said address data.

Abstract: A record carrier is described comprising a zone with a visually detectable pattern composed of pattern elements arranged along at least one track. The pattern elements comprise a marked zone having an optical property deviating from a background, the marked zones having a width Wm transverse to the track direction and a length Lm along the track direction, wherein at least two or more pattern elements have a marked zone with a mutually different width Wm. In this way, an increased visibility of the visual pattern is achieved. Likewise a method and an apparatus for recording an optical record carrier is included.

Abstract: 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 (IND1) of the servo actuator is determined from at least one of the SES and SCS. IND1 is compared against a first pre-determined threshold (ITHR1), determining a first servo margin (MAR1). The scanning velocity is set in dependence on at least MAR1. 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.

Abstract: A method of determining a maximum allowable read power for a drive-record carrier combination is described. The method finds a forward-sense setpoint value to control a light power control loop, by reading data from the record carrier at which degradation of the data occurs. This technique is useful for all optical storage devices such as CD, DVD and Blu-ray players and recorders.

Abstract: An optical reading/writing apparatus has an optical head that includes a collimator and a lens. For efficient and reliable focusing control for writing an empty optical disk, calibration of focus offset and spherical aberration is executed by setting a boundary and performing data-reading in an OPC area only with combinations of focus offset and spherical aberration within the boundary. Accordingly, an optimum combination of focus offset and spherical aberration is determined for focusing compensation in subsequent writing operation of the empty disk.

Abstract: The present invention relates to an information reproducing method for reproducing information recorded on an information recording carrier with several information layers by radiating light onto the carrier being e.g. an optical disc. The method comprises the step of 1) focusing the light at a first information layer or a second information layer, where the first layer and the second layer are adjacently positioned in the information recording carrier, 2) performing radial tracking on the reflected light from the information recording carrier, and 3) assessing form the radial tracking if the light is focussed on a clockwise or a counter-clockwise oriented spiral relative to the focussed light. In a particular embodiment, the assessment of whether the light is focussed on a clockwise or a counter-clockwise oriented spiral relative the light is utilized for indicating the identity of the layer on which the light is focussed.

Abstract: A method of analyzing the quality of optical effects on an optical recording medium as well as applications of the method in connection with optimizing a write strategy and analyzing the write quality for an optical recording medium are disclosed. The method comprising the steps of determining waveforms of a measured and a nominal optical signal, and calculating an amplitude-difference parameter from a difference in the measured and nominal waveforms. A quality measure of the optical effects can thereby be determined from the amplitude-difference parameter. The applications of the method include, but are not limited to: a device for reading optical effects from an optical storage medium with means for determining the an amplitude-difference parameter, an optical recording apparatus with means for adjusting the power level and/or level duration in a write strategy and an IC for controlling an optical storage apparatus.

Abstract: 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.

Abstract: The invention described is an apparatus for reproducing information from an information carrier (11) comprising: a waveform equalizer (6) for obtaining a corrected signal (S?) by performing a waveform equalization to a read signal (S), the waveform equalizer (6) having an amplifying element with a gain (K); and gain setting means (1) for reading a numerical gain setting stored on the information carrier (11) and setting the gain (K) of the amplifying element to a value related to the numerical gain setting. By reading the numerical gain setting from the information carrier, the apparatus is able to set the gain (K) of the waveform equalizer to the optimal value for suppressing noise and inter symbol interference. The equalizer can be followed by a limit equalizer, the gain of which can also be wave form read from the information carrier.

Abstract: A method for determining a parameter space for finding optimal operating parameters for reading or writing storage medium is provided. In an embodiment of the invention, the method includes: setting a first parameter range of a first operating parameter and a second parameter range of a second operating parameter; normalizing the first and the second parameter ranges respectively and forming an initial parameter space based on the normalized first and second parameter ranges; and rotating the initial parameter space by a rotation angle and forming an actual parameter space based on the rotated initial parameter space. The actual parameter space is expected to result in more reliable optimal operating parameters.