Patent ID: 10360940

Abstract:
Subject-matter is that between an inner edge and an outer edge of a lead-in area, are created by mechanical means grooves in the form of concentric circles around the central axis with the profile of the letter “V” in the protective layer, wherein these grooves have peaks and edges are created in such a way that the groove with the largest possible diameter of the circle does not exceed the inner part of the outer edge and the groove with the smallest possible diameter of the circle does not exceed the inner edge of the lead-in area, wherein the density of the grooves is such that edges of the grooves are touching each other on the surface of the protective layer and between the individual edges of the grooves there is no area undamaged by the grooves. Non-standard audio discs and video discs are manufactured by pressing from the matrix, they contain lead-in area data area and lead-out area and in the area with the radius from 18.00+1 mm to 23.50+1 mm are provided with the zone of the mechanical protection, which contains a set of grooves in the form of concentric circles, with the profile of the letter “V”, which are arranged closely to each other in such a way, that their upper edges are touching.