SYSTEM FOR REPRODUCING PULSE TIME MODULATED WAVEFORMS STORED ALONG A DIFFRACTIVE TRACK

摘要

A record is provided for storing a pulse time modulated waveform along a recorded track having an axis. The record comprises a substrate having at least one engraved face carrying an embossed print of the recorded track. The engraved face is a phase object constituted by a succession of diffractive elements distributed along the axis in accordance with a sequence of pulses of the waveform. These diffractive elements have non-uniform length and spacing and the width of the embossed print is substantially constant along the axis. The non-uniform length and spacing of the diffractive elements respectively measured along said axis are at least equal to the width of the embossed print. The diffractive elements are engraved in the form of depressions or relief depressions in the engraved face.