Optical information recording medium and production method thereof
US6258432A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 27, 1999 |
| Grant date | Jul 10, 2001 |
| Priority date | — |
| Expiry date | Apr 27, 2019 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/21
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical information recording medium comprising a thin plastic substrate of 0.6 mm or thinner, wherein the substrate is protected against strain without being limited by a film structure and a film formation condition. A single-layer or multilayer thin film (70) is formed on a plastic disk-like substrate having a center hole (10). This thin film (70) has a strain relief area (72) inside a recording area (71). This strain relief area (72) is formed by setting an outer diameter of an undeposited inner portion (5) to a value satisfying the following formula (1), for example: A.sub.0.ltoreq.A.sub.X.ltoreq.-0.172P+0.163 where A.sub.0 : diameter of center hole, A.sub.X : outer diameter of undeposited inner portion, P: total strain occurring in thin film when film depositing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.