Printing apparatus and method using a raster buffer divided into a writing layer, a reading layer, and a write-waiting layer for handling data overflow
US5191430A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 10, 1991 |
| Grant date | Mar 2, 1993 |
| Priority date | — |
| Expiry date | May 10, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K2215/0065
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
In a printing apparatus, a raster buffer for storing dot image data is divided into three layers in the direction of auxiliary scanning, and the respective layers are assigned to a writing layer in which a font pattern read from a font memory is written, a reading layer from which dot image data that have been written are read, and a write-waiting layer in which a font pattern that has overflown the writing layer is written, with the writing layer and the write-waiting layer having a capacity for storing a character having the biggest size among those which are used frequently. Prior to printing of dot image data, a font pattern is written in the writing layer, and the definition of the layer in which writing has been made is changed to a reading layer, dot image data is then read from the reading layer, the definition of the write-waiting layer waiting for the next writing is changed to a writing layer, and the definition of the reading layer from which the reading has been made is changed to a write-waiting layer, with such change of definition being made successively.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.