Abstract A format is provided with special error check pits in order to take countermeasures when readout errors occur. Furthermore, in order to take countermeasures when readout errors occur due to local contamination on the optical data recording card, the data are distributed and then recorded. In order to perform the efficient access to data, required data representing a predetermined address value are also recorded together with the general data. A method is also provided for forming pits by modulating the digital signal and an optical system as well as a signal processing system of a reading device used in connection with the optical data recording cards. The optical data recording cards on which are recorded the data by the method of the present invention can be used in various fields as recording media for storage of computer programs, images, musical data and various data bases.
A data recording method for recording data on an optical data recording card having a plurality of data arrays, wherein a pit for indicating the center line position of a data array is added at either end of said data array and at least two parallel bars which serve as a guide in case of reading the data arrays are extended in a vicinity of one of the ends of said data arrays in a direction perpendicular to said data arrays, said pit being located between said bars and said data arrays and a distance between said bars and said pit being set to a predetermined constant, the length of said pit indicating the center line position being shorter than those of pits constituting each data array.
Claim 2
Dependent Claim
127 words
A data recording method for recording data on an optical data recording card having a plurality of data arrays, wherein a pit for indicating the center line position of a data array is added at either end of said data array and at least two parallel bars which serve as a guide in case of reading the data arrays are extended in a vicinity of one of the ends of said data arrays in a direction perpendicular to said data arrays, said pit being located between said bars and said data arrays and a distance between said bars and said pit being set to a predetermined constant, the length of said pit indicating the center line position being shorter than those of pits constituting each data array.
Claim 3
Dependent Claim
28 words
The data recording method of claim 1, wherein said pit indicating the center line position is a circular pit, the center of which coincides with said center line.