US 8,127,820 B1 · System for producing optical recording medium

Abstract

Techniques for producing optical medium that can be read at substantially high speeds with greater stability and accuracy are disclosed. According to one aspect of the techniques, a molding station includes an optimized stampler which does not have an exact inverse image of a replica. To account for an inherent distortion in a substrate after being stamped, a stampler is pre-distorted so that the pit geometry in the stamped substrate becomes nearly perfect after the inherent distortion. In one embodiment, the injection of a molten material, the mold position and compression are respectively controlled to account for possible non-uniform density distribution of the material. To provide an effective bonding process, a bonding station is employed with what is referred to as index bonding technique and/or pulse bonding technique. The index bonding is provided to ensure that non-flatness of substrates is compensated when two substrates are bonded together so as to minimize possible dynamic imbalance of a disc. The pulse bonding is provided to eliminate bubbles from a type of glue used to bond two substrates, wherein a high voltage used to generate a pulse of electromagnetic field is programmable in accordance with the substrates and the characteristics of the glue.

Claims26

Dependent claims

A system for producing optical medium, the system comprising:

a stamper designed to cause a substrate being molded to have a distorted pit geometry being longer and thinner than that of a perfect pit geometry supposed to be created on the substrate, the distorted pit geometry being reversely corrected in inherent distortion of the substrate due to a short molding time such that a pit geometry on the substrate becomes nearly perfect;
at least a first and a second molding station, the first molding station producing first substrates and the second molding station producing second substrates, wherein the first molding station includes the stamper, the pit geometry on each of the first substrates from the stamper is distorted but reversely corrected after each of the first substrates is released from the first molding station;
at least a first bonding and a second bonding station, each of the first and second bonding stations sequentially receiving the first and second substrates and bonding one of the first substrates and one of the second substrates with a type of glue between the first and second substrates to form a disc or part of a disc;
and
means for curing the glue.

2 more elements

A system for producing optical medium, the system comprising:

a stamper designed to cause a substrate being molded to have a distorted pit geometry that compensates for inherent distortion in a short molding time, the distorted pit geometry being longer and thinner than that of a perfect pit geometry supposed to be created on the substrate and the distorted pit geometry being later reversely corrected such that the substrate becomes nearly perfect;
at least a first and a second molding station, the first molding station producing first substrates and the second molding station producing second substrates, each of the molding stations receiving an injection of a molten material in a mold cavity formed by two mold plates one of which includes the stamper, a pit geometry on each of the first or second substrates from the stamper is distorted but reversely corrected after each of the first or second substrates is released from the each of the molding stations, wherein the injection and movement of the mold plates and pressures applied to the mold plates are respectively controlled and programmable in accordance with a density distribution of the molten material;
at least a first bonding and a second bonding station, each of the first and second bonding stations sequentially receiving the first and second substrates and bonding one of the first substrates and one of the second substrates with a type of glue between the first and second substrates to form a disc or part of a disc;
and
means for curing the glue.

2 more elements

Dependencies are inferred from the claim text.

System for producing optical recording medium

Life of this patent

System for producing optical recording medium

Life of this patent

Abstract

Claims26