초록 ▼

An optical storage disc has portions for storing pre-recorded or mastered information and portions for storing user writable information, where the mastered portion and the writable portions have different storage capacities or areal data densities. During manufacture, a substrate is formed with a s

An optical storage disc has portions for storing pre-recorded or mastered information and portions for storing user writable information, where the mastered portion and the writable portions have different storage capacities or areal data densities. During manufacture, a substrate is formed with a sequence of bumps to represent the mastered information and a series of grooves and lands, where information can later be written on the lands. A phase-change material is deposited over the substrate, the phase-change material changing both physical structure and optical constants when written to, e.g., by a laser.

대표청구항 ▼

We claim: 1. A first surface optical storage disc, comprising: a circular substrate having a first principal surface and an opposing second principal surface; a spiral track of bumps formed on a first portion of the first principal surface, wherein the bumps represent pre-recorded information, the

We claim: 1. A first surface optical storage disc, comprising: a circular substrate having a first principal surface and an opposing second principal surface; a spiral track of bumps formed on a first portion of the first principal surface, wherein the bumps represent pre-recorded information, the bumps being separated by planar regions; lands formed on a second portion of the first principal surface, the lands being separated by grooves; and a phase-change material deposited on the first portion and the second portion of the first principal surface; and a dielectric layer sputtered over the phase-change material; the first surface disk having no additional layers overlaying the dielectric layer, the first portion thereby being a ROM portion and the second portion being a RAM portion, wherein a combined thickness of the phase change material and the dielectric layer is such that the dielectric layer defines coated bumps having a first height with regard to coated planar regions in the first portion, and coated lands having a second height with regard to coated grooves in the second portion, and wherein a data density of the first portion is less than a data density of the second portion. 2. The disc of claim 1, wherein the first portion has a data density of approximately 3.8 Mbits/sqmm, and the second portion has a data density of approximately 4.7 Mbits/sqmm. 3. The disc of claim 1, wherein the phase-change material is an alloy of Sb, In, and Sn. 4. The disc of claim 1, wherein the outer diameter of the disc is approximately 50 mm or less. 5. The disc of claim 4, wherein the outer diameter of the disc is approximately 32 mm or less. 6. The disc of claim 1, wherein the thickness of the disc is approximately 0.6 mm or less. 7. The disc of claim 1, wherein the substrate comprises a polycarbonate material.