Optical disc and injection compression molding die for producing the same
US6576317B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 1, 2001 |
| Grant date | Jun 10, 2003 |
| Priority date | — |
| Expiry date | Feb 24, 2021 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/21
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical disc capable of preventing damages on a printing plate and an injection compression molding die capable of producing such optical disc substrate without raising the accuracy of the die are provided. An optical disc substrate according to one embodiment of the present invention has a ring-formed projected portion on the outer periphery of the printable plane slightly recessed inwardly from the outer edge of the disc. Such optical disc substrate can be produced using a molding die in which a readout-side mirror has a ring-formed groove on the inner surface thereof in the vicinity of a sliding portion between such readout-side mirror and a cavity ring.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.