Facsimile transceiver
US4291339A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 15, 1978 |
| Grant date | Sep 22, 1981 |
| Priority date | — |
| Expiry date | May 15, 1998 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/411
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A scanner scans an original document in two orthogonal directions and produces binary data signals representing the document. An extractor combines each two scan lines into one scan line by taking the logical sum of the data signals in corresponding positions in the two original scan lines. Each second data signal is removed. The data signals in even positions in one line are removed and the data signals in odd positions in the succeeding line are removed, thereby removing the data signals in a zig-zag manner. The data signals so processed are subjected to run-length encoding. In a receiver, the data signals are run-length decoded and fed into an interpolator which senses the data signals and inserts data signals into the spaces from which data signals were removed in accordance with a predetermined logical function. The interpolator controls a printer to print each scan lines twice to reproduce the original document.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.