Image reading apparatus capable of eliminating moire pattern
US4939590A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 25, 1988 |
| Grant date | Jul 3, 1990 |
| Priority date | — |
| Expiry date | Aug 25, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/409
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
When an original formed by using a dot screen is read, a key which corresponds to the screen line number of the dot screen is inputted. By the key input, a suitable magnification rate data based on the screen line number is set for eliminating moire patterns. An optical enlarging magnification rate and reducing magnification rate are determined based on the set magnification rate data. The image of the original is projected on an image sensor at this optical enlarging magnification rate and is converted into electrical data. The electrical data are reduced electrically at the reducing magnification rate to be outputted as the image data.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.