GENERATION OF CHANNEL BIT DATA FILES CORRESPONDING TO ANGULAR SECTIONS OF SUBTRACK, FOR RECORDING OPTICAL METATRACK DISCS

摘要

A method and device are disclosed for writing data marks representing a sequence of channel bit values to an optical disc or a master disc along either one or more concentric or spiral data tracks or along at least one concentric or spiral metatrack consisting of two or more parallel concentric or spiral sub-tracks. The method comprises the steps of - partitioning the sequence of channel bit values into an ordered set of two or more channel bit data files, - providing a periodic rotational motion and a radial motion of the disc and of at least one writing beam spot on the disc relative to each other so as to guide each writing beam spot along at least one data track or sub-track, - periodically providing an angular position signal derived from the rotational motion and indicative of the completion of one full turn of the rotational motion or a predetermined fraction thereof, - switching to a respective channel bit data file next in order with each angular position signal and writing a respective section of the sequence of channel bit values contained therein to the disc. According to the method of the invention, in the partitioning step the length of a respective section of the sequence of channel bit values to be contained by a respective channel bit data file is determined such that the complete respective section of the sequence of channel bit values contained by the channel bit data file is written to the disc between two consecutive angular position signals. The method provides an enhanced precision in the alignment of data marks, which is especially useful for synchronizing two-dimensional data patterns on a disc. Also disclosed are a method and a device for channel bit data file construction from a sequence of channel bit values, and a channel bit data memory.