Method and apparatus for generating a character image
US4942390A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 1, 1987 |
| Grant date | Jul 17, 1990 |
| Priority date | — |
| Expiry date | Apr 1, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K15/02
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
This invention relates to a method for generating character images using a font compression algorithm that reduces the storage requirements associated with low-cost, high resolution printers. An expanded character image has original print slices and duplicate print slices identical to one or more of the original print slices where the duplicate print slices are eliminated in the compressed character image. The compressed character is expanded using a repetition mask that identifies the number and location of the duplicate print slices. The technique for expanding the compressed character is such that printing can be performed in real time, in either a forward or reverse direction with only minimal effects on processing. This invention also provides a means for supporting multiple pitches, such as 10 CPI, 12 CPI and Proportional Space Mode (PSM), within those storage constraints. The technique of this invention is efficient enoughh to be performed by microcode in real time, yet provides for significant reduction in the overall memory required for storing the font data.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.