Image generation from transition-encoded font information
US4847607A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 15, 1987 |
| Grant date | Jul 11, 1989 |
| Priority date | — |
| Expiry date | Sep 15, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G5/24
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Transition-encoded font image information--being a form of information flagging all pixel displacement locations upon a scan line of a raster scanning image generator, nominally a laser printer, whereat a marker, nominally a laser beam, transits from marking white to marking black, and from marking black to marking white, during the generation of the one scan line of a font image--is stored in two random access memories (RAMs) each having a nominal 10,320+ address corresponding to the 1200 pixel positions per inch across an 8.6" scan line. The two RAMs are sequentially read in parallel from the start-of-scan of the scanning marker, or laser beam. The successively read transition-encoded information is used to decrement a counter upon each black-to-white transition and to increment the same counter upon each white-to-black transition. The sign bit of the count within the counter is used to control the on/off, black/white condition of the laser beam marker so that white is imaged upon the scan line when the counter is negative, and so that black is imaged when the counter is positive, at pixel rates to 35 MHz.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.