Odme

Del Mar Avionics, Inc.

Robert L Cubit

Bruce E Del Mar

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. The residual berm, however, is eliminated by an additional process and step of passing the recently recorded disc under a UV illumination source before application of a final conductive layer to the disc.

Optical disk mastering system

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.

Disc master drying cover assembly

The invention discloses a method and an apparatus for creating an optical disc master by forming 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. A disc substrate has a very thin partially reflective layer applied to the surface of the optical disc upon which data will be recorded. The substance used to make the partially reflective layer is normally considered opaque in more commonly occurring thicknesses. However, the partially reflective layer, is created to be so extremely thin that it becomes partially optically transparent. The partially reflective layer then has spin coated, thereon, an optically active lamina to enable the recording of data on the disc by laser means in the form of pits. The pits are created by having a laser light focusing on both the partially reflective layer and the optically active lamina, both which react 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. The residual berm, however, is eliminated as disclosed in this application by an additional process and step of passing the recently recorded disc under a UV illumination source before application of any additional layer to the disc. An OD Master can be created by finally depositing a conductive and reflective lamina over the pitted active lamina. The invention is also useful in providing increased laser tracking. Here, the partially reflective layer provides increased signal to noise ratio, enhancing laser tracking in both the recording and playback modes.

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Westminster, CA, United States of America

Robert L Cubit