Abstract: Thus, in conventional, one-dimensional optical storage, the data is arranged in a linear fashion and is read out by a single spot (102). In order to increase data rates and storage capacity, it has been proposed to arrange the data in an isotropic, hexagonal lattice (200) and employ multiple spots (202) for read-out. Due to the high bit-intensity, 2D inter symbol interference (ISI) has a significant effect on bit detection. Aberrations in the readout spots (202) can change the form of ISI and, therefore, hamper 2D bit detection. Thus, a method and apparatus is proposed, wherein by evaluating the ISI of the readout spots (202) by scanning over a known calibration pattern, i.e. a bit pattern selected such that its optical response is characteristic of the shape of the readout spot, the aberrations in the readout spot can be determined and beneficially compensated for, as required.

Abstract: The invention relates to a data processing system comprising a computer having a memory for storage and retrieval of at least one application program embodying a pre-determined functionality, and for storage and retrieval of at least one data-file, which computer comprises a user interface for entertaining communication between the computer and a user of said computer, whereby the at least one application program comprises validation software for checking and enabling the operability of said application program in connection with the at least one data-file, and processing software for executing the said functionality in connection with the at least one data-file in dependence of said enabling by the validation software, whereby the validation software is executable separately and independent from the processing software.

Abstract: A recording apparatus for recording channel symbols of a channel data stream on a record carrier (50), said apparatus being adapted for recording said channel symbols as a channel band (cb) of at least two symbol rows (sr) one-dimensionally evolving along a first direction (t) and aligned with each other along a second direction (r), said two directions constituting a two-dimensional lattice of symbol cells (sc) each being associated with a symbol area (sa) of the record carrier (50).