Patent ID: 6507545
Filing Date: 2003-01-14
Classification: G11B

Abstract:
A method for data reading/writing using an optical carrier comprising the following stages:production of an optical data carrier as a two- or three-dimensional optical medium having at least one or many information carrying layers with surfaces of said layers containing recorded information; generation on said surfaces of said layers of a multitude of optically readable numerical data (information pits) encoded in such a way that on each said surface one data byte is written in a field (microregion) consisting of ten (2Ã—5) square elements (â€œ(2Ã—5)-fieldâ€ ) of definite size, wherein each of said square elements contains or not changes (different from the surface areas carrying no information) in optical properties (absorption, reflection and fluorescence factors, refraction index, birefringence factor, etc.) testifying either the presence or absence of information pits therein, with one data byte occupying on said surface an area of 10S, where S=aÃ—a is the area of one square element, a is the square side, and where adjacent bytes are positioned on the surface of information layers close to each other in a gap-free manner, with total 256 combinations forming one data byte represented on the surface of an information layer by â€œ(2Ã—5)-fieldsâ€  of two types, with the first 222 combinations represented by fields wherein each information carrying square element (pit) has inside the â€œ(2Ã—5)-fieldâ€  at least one identical adjacent element across or lengthwise, while each square element contaning no information pit has inside the field an identical adjacent element (parity condition) and at data recording that particular â€œ(2Ã—5)-fieldâ€  is selected from the pair of â€œ(2Ã—5)-fieldsâ€  which, when butted to the leftside field therefrom, enables the parity condition inside each longitudinal strip consisting of butted to each other fields (bytes); simultaneous (parallel) data reading from a designated information layer of the optical carrier using a source of electromagnetic radiation with a wavelength suitable for optical reading of data stored in the information carrier as local changes in optical properties of information layers and the optical system enabling simultaneous (parallel) reading of data as a multitude of information pits through generating a requisite, uniform in terms of intensity spatial configuration of the reading electromagnetic radiation in the site of the designated information layer and image by means of read-off radiation of this spatially intensity-modulated configuration to a specified scale in the plane of a matrix photoreceiver while keeping said photoreceiver intact of the reading radiation; conversion of the space-modulated pattern of the read-off radiation in the plane of said photoreceiver to output electric signals and indetification of said signals, with simultaneous indentification of pairs of adjacent square elements of each transverse column of the â€œ(2Ã—5)-fieldâ€  while reading, and in so doing both elements are considered to be information carrying pits when the signals received from individual photodetectors â€œcoveringâ€  respective square elements of the information layer exceed a certain level L1 and not considered to be information carrying pits when both said signals do not exceed a certain level L21, while whenever the above-mentioned conditions are not met, the square element with a larger signal level is considered to be the information pit and the other element accordingly is not considered to be the information carrying pit.