Producing a replicate video disc by a method of photographic contact printing
US4980262A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 29, 1979 |
| Grant date | Dec 25, 1990 |
| Priority date | — |
| Expiry date | Aug 29, 1999 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S430/146
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A photographic contact printing process is disclosed having application in the mass production of replicate video discs from a master disc, and other applications wherein it is desired to replicate micro-detail over a relatively large area. A problem with conventional contact printing from a mask to a photographic medium is one of maintaining intimate contact over a relatively large area since dust, dirt, etc., are almost impossible to completely eliminate in any practical manner. In accordance with the present invention, a contact printing process is provided wherein intimate contact is not necessary for making high quality contact prints. The present invention recognizes that in contact printing information from a master disc to a replicate disc, the contact printing process is significantly less sensitive to imperfect contact between the master disc and the replicate disc if one employs a replicate disc comprising a photosensitive material having a certain optical properties. In particular, the photosensitive material initially has a high level of absorption to the actinic radiation used for exposure but, under the influence of such actinic radiation, the absorption decays to a …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.