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AssigneeMinnesota Mining and Manufacturing Company
InventorsJerry L. Alexander, Sankar B. Narayan, Sten R. Gerfast, Charles E. Nelson
Estimating the term…
Stretched surface recording disk (SD) 10 comprises an annular support 12 having raised annular ridges 42 and 28 at its inside and outside diameters 22 and 30 with a base portion 24 in between the two ridges, and an annular recording medium film 14 held in radial tension and stretched across the base portion by adhering the film to attachment surfaces 48 and 36 near the inside and outside diameters respectively. The SD is annealed twice during manufacture to relieve stress in the stretched film 14. This annealing results in SD essentially free from track anisotropy and stress distribution anisotropy in the plane of the disk. As a result, data tracks are more stable than in previous SD, track density can be greater, and the SD is generally more reliable.
A process for annealing a stretched surface recording disk comprising a rigid annular support, having at least two concentric raised annular reference surfaces and an annular polymeric film, having a recording layer, attached to the support and stretched between and supported by the raised annular reference surfaces, said process comprising:
The process of cIaim 3 wherein the electron beam irradiation process of step B is performed using an inert atmosphere having less than 60 ppm oxygen, and the annealed film and annular support are exposed to no more than about 10 Mrad of radiation.
A process for annealing a stretched surface recording disk comprising a rigid annular support, having at least two concentric raised annular reference surfaces and an annular polymeric film, having a recording layer, attached to the support and stretched between and supported by the raised annular reference surfaces, said process comprising:
Dependencies are inferred from the claim text.