Abstract: The invention discloses a method and an apparatus for creating an elementary optical disc master with but a single layer to be applied to a disc substrate to form pits having ideal shapes and without berm buildup. These ideally shaped pits are improvements in the technology of disc mastering, due to the manufacturing and data playback advantages that are inherent in the ideally shaped pits. An optically active lamina consisting of a dye polymer solution of nitrocellulose and a increased dye additive is spin coated directly to a pregrooved polycarbonate substrate to enable the recording of data on the disc by laser means in the form of pits. The pits are created by having a data modulated laser focusing on the optically active lamina which reacts to the irradiation causing a pit to be formed. The resulting pit more often than not possesses a residual raised berm area surrounding the pit, in what is considered to be a less than ideal shape for a pit.

Abstract: A spin coater drying cover is disclosed having unique properties and construction to enable accurate control of the drying process of an optically active lamina of a Nitrocellulose Dye Polymer solution on a Polycarbonate disc substrate. The cover is configured with an orientation platform allowing micro adjustment of the angle and distance of a porous gas filter disc of the cover in relation to the optically active layer. The filter, essentially parallel and concentric to the disc substrate, can be varied from a flat, concave or convex camber to cause gas flow over the disc substrate to be such that a variable linear ramp of the optically active lamina can be achieved, with a thicker layer at the periphery than at the center of the disc. This enables deeper data pits to be formed at the difficult to mold outer disc periphery, thus increasing yield in a disc mastering process.