Abstract: A method of storing/retrieving information to/from an optical disc by means of an optical system with a cut-off frequency ?cut-off, above which frequencies cannot be detected, is disclosed. The invention relates to Run Length Limited encoded information. According to the invention, some frequencies of the encoded information can be higher than cut-off frequency of the optical system, such that the equation 4*(d+1)*Lcd*NA/?laser<1 is satisfied, where d+1 is the minimum run length of the coding, Lcd is the length of a channel bit, NA is the numerical aperture and ?laser is the wavelength of the optical system. Hereby, the capacity of the optical disc is increased, while the prevailing coding technique is used. Moreover, the invention relates to a disc for storing of data, a drive capable of storing data and an apparatus for manufacturing optical discs.

Abstract: When writing data to an optic disc with a constant linear velocity, and encountering a disc error, data is written into the defect management area of the disc without changing the rotational speed of the disc, or at least without changing the rotational speed of the disc sufficiently to maintain a constant linear velocity. This allows an increase in the rate at which data may be written to the optical disc. It also avoids or reduces the need for the rotational speed of the disc to be changed, which allows a further improvement in the time taken to write data to the disc. In order to continue writing data to the disc without changing the rotational speed, the data rate must be increased while writing to the defect management area. For this to be possible, the data must be written into an “iced” or unformatted part of the defect management area.

Abstract: A wobble signal is generated from at least two elementary signals (A,B,C,D) detected by scanning a wobbled track of a data carrier. The invention proposes a solution for eliminating the noise of various origins in the wobble signal, notably the high frequency data leakage into the wobble signal due to radial asymmetry introduced in the diffraction pattern on the detector, whatever the reason for this radial asymmetry. According to the invention, the at least two elementary signals are filtered with at least an adaptive filter (40), and said filtered elementary signals are subtracted (44) from said wobble signal (PP) thereby generating an improved wobble signal.