Method and apparatus for dual resolution photographic reproduction of line and continuous tone graphic materials
US4004079A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 14, 1975 |
| Grant date | Jan 18, 1977 |
| Priority date | — |
| Expiry date | Nov 14, 1995 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/4055
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method and apparatus are disclosed for producing photographic reproductions of line and continuous tone graphic materials. The invention is useful in the newspaper field for opto-electrically producing plate-ready negatives or plates themselves from line and continuous tone copy. The line and continuous tone graphic materials are scanned incrementally to produce high resolution signals representative of the gray levels of incremental areas of both the line and continuous tone materials. A plurality of the high resolution signals representing the gray levels of the incremental areas of the scanned continuous tone material are combined to produce low resolution signals representing the gray levels of larger, low resolution incremental areas of the scanned continuous tone graphic material. The high and low resolution signals are employed to control an incremental, scan exposure of a photosensitive member. The photosensitive member receives an exposure that is a function of the gray levels of the high resolution incremental areas of the line graphic material and of the gray levels of the low resolution incremental areas of the continuous tone graphic material. Significant reductions …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.