摘要 |
<p>The invention concerns a method for the distribution of data marks on a medium. The image of the data source (44) is recorded on an optical medium (2). The data is read out with the help of identifying marks on the detected image. The data to be recorded are coded with a coding which prohibits the immediate succession of data with identical states above a predetermined number of times. In the matrix of the data source arrays of a predetermined size and position are defined, the arrays containing identifying data marks and user data marks. There is also disclosed an apparatus having a two-dimensional data source (44), and an optical system for imaging the data source through an object beam (35) and reference beam (36) onto an optical medium (2). The optical medium is positioned in the Fourier plane associated with the image of the data source (44). Beside the Fourier plane of the hologram, the optical system comprises a further Fourier plane (51) between the data source (44) and the hologram (9), and there is a spatial filtering means in the further Fourier plane.</p> |