Method of and means for printing a multilevel representation of an image
US4912562A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 6, 1989 |
| Grant date | Mar 27, 1990 |
| Priority date | — |
| Expiry date | Mar 6, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/4058
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A half-tone reproduction of an object on a recording medium is produced using gray level values contained in the cells of an object matrix representative of the object. An actuatable marking device is operatively associated with and displaceable relative to the recording medium for printing a dot thereon at an exposure point determined by the location of the marking device at which the latter is actuated. A representation of the coordinates of the marking device is obtained, and converted to modular coordinates representative of the coordinates of the exposure point on a mesh of a fictitious of half-tone screen having a predetermined angular orientation relative to the print medium. A threshold screen value is computed from the modular coordinates, and a gray level value is obtained from the cell of the object matrix closest to the coordinates of the exposure point. The threshold value is compared to the obtained gray level value, and an actuating signal is produced depending upon the results of the comparison.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.