Oce-Nederland B.v.

Theodorus H Willems

Franciscus H Tunnissen

Cornelis W Venner

Gerardus G Kessels

A raster image memory which serves as a bit-map memory for the storage of the bit representation of a whole page to be printed for a raster output scanner is connected to a raster image processor by a synchronous raster image bus having a number of data and modification code lines. Each memory element of the bit-map memory corresponds to a position on the page. The raster image processor fills the raster image memory. A logic processing unit is disposed between the raster image bus and the bit-map memory so that one input of the logic processing unit is connected to the data lines of the raster image bus and another input of the logic processing unit is connected to the data outputs of the bit-map memory. The logic processing unit is also capable of performing a number of logic operations on the data presented at the inputs of the logic processing unit in response to the signals on the modification code lines.

Raster image memory

The present invention is a front-end system for the conversion of graphical data and coded font data into a serial pixel-bit stream for a raster output scanner, such as a laser printer. The front-end system includes a front-end controller, input/output means, which can be connected to a computer or a data network, and a memory for storing graphical data and coded font datat. Final printing format is determined by a fine formatter. The present front-end system also includes a bitmap memory for storing a bitmap representation of the page to be printed, a bitmap filler for expanding the data and placing them into the bitmap memory, and a bitmap reader. The functions of the front-end controller and of the input/output means are implemented in a first processor and the functions of the fine formatter and the bitmap filler are implemented in a second processor. The bitmap reader is formed by dedicated hardware logic. With the present construction, a high speed page processing can be achieved with a reduced number of processors.

Front-end system for a raster output scanner

Raster image processor for filling a page-size raster image memory and for the conversion of the data stored in the raster image memory into a serial pixel-bit stream for a raster output scanner which includes a microprogrammable central processing unit; a raster image bus interface connected to a synchronous raster image bus system; a raster output scanner interface connected to the raster output scanner; an interface connected to the asynchronous bus system; and a synchronous raster image processor bus system connecting the microprogrammable CPU to the raster image bus interface to the raster output scanner interface, and to the interface which is connected to the asynchronous bus system.

Growing community of inventors

Horst, Netherlands

Theodorus H Willems