HERMETICALLY SEALED OPTICAL PLASTIC SUBSTRATE

Publishing Venue

Xerox Disclosure Journal

Abstract

Two problems exist with prior art optical disks: (a) oxidation of the media and (b) disk radial runout. Thin films of Si02 and A$O3 deposited over tellurium (Te), the writing medium, will eliminate both problems.

EROX DISCLOSURE JOURNAL

HERMETICALLY SEALED OPTICAL PLASTIC SUBSTRATE
Roberta-M. Fay
Richard D. Weir
Raymond G. Schliesmann

Proposed Classification
U.S. C1. 365/126 Int. Cl. Gllc 11/46

BACKER

PLATE

l-----7

SiO2

GLASS

I

Two problems exist with prior art optical disks: (a) oxidation of the media and (b) disk radial runout. Thin films of Si02 and A$O3 deposited over tellurium (Te), the writing medium, will eliminate both problems.

One such configuration may be seen in the figure. To obtain a very low cost media package, a plastic substrate, instead of glass may be used.

The "suitable adhesive" is a capillary filled transparent adhesive compatible with SiO thin films and/or glass. Although PMMA is listed as the data disk substrate

be PMMA coated on both sides with Si02 or it can be glass (preferably chemically strengthened glass with enhanced fracture resistance).

II 1

ma 3 ^{erial, other} inexpensive plastics can be used in its place. The backer plate can

Volume 8 Number 3 May/June 1983 279

HERMETICALLY SEALED OPTICAL PLASTIC SUBSTRATE (Cont'd)

The disk edges are coated during the Si02 depositions and masked during the tellurium depositions so the SiO Al-

The Si02 undercoating will also minimize attack via the PMMA surface.

In order to use this configuration, some changes in the optical components are required. First, a computer modeling must be done (for second surface ablation, the refractive indices...