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Concurrent PostScript Rasterizers Based High Throughput Color Printer Architecture

IP.com Disclosure Number: IPCOM000118540D
Original Publication Date: 1997-Mar-01
Included in the Prior Art Database: 2005-Apr-01

Publishing Venue

IBM

Related People

Heiney, RL: AUTHOR [+4]

Abstract

PostScript printers that require over 100MB/second of data require special architecture and design to make it happen. The Xeikon is one such printer and it is a serious limitation that such a printer cannot be used without first pre-rasterizing the entire PostScript job.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 14% of the total text.

Concurrent PostScript Rasterizers Based High Throughput Color Printer
Architecture

      PostScript printers that require over 100MB/second of data
require special architecture and design to make it happen.  The
Xeikon is one such printer and it is a serious limitation that such a
printer cannot be used without first pre-rasterizing the entire
PostScript job.

      The main thrust of this design is to emphasize the different
components of this proposed architecture.  We have presumed that it
is important to Raster Image Processor (RIP) and print as part of an
IBM value add to this Xeikon engine.  Most people familiar with the
nature of PostScript (PS) will agree that it is safest to pre-RIP PS
to disk before proceeding.  While we agree in principle with this, we
believe that for each job an attempt must be made to RIP a little
ahead of printing in order to provide the customer with rated-speed
printing in conjunction with a quickest possible job turn-around
time.  Other features include unattended mode operation, error
recovery, and color transformation.  This printer design is referred
to as Teak3 throughout the text.

Current Design for Teak (1 & 2)
  1.  Printer Spec: 35 ppm, 70 ipm, 600dpi, duplex, A4,
       color, 1, 2, 4 bpp (Page size = 5-6 MB * # of planes * bpp)
  2.  Currently uses RLE (for fast compression/decompression),
       NO error recovery
  3.  Prints only PS

Function of components

Controller -

Controls the RIPs and uses fast-and-wide Small Computer System
Interface (SCSI) to write page images to print streamer (dual ported
disk cache).  Alternately, the pages can be written directly to the
PES 486 based hardware controller.

Print Streamer -

Dual ported (for simultaneous read-write) disk cache with eight
SCSI-2 cards cabled to corresponding SCSI-2 cards on Xeikon print
heads (there are 10 print heads - the two extra for special inks
functional).  There are 10 disks with 2GB/head for duplex operation.
The print streamer is also attached to the PES controller since the
PES is  still required to control the motors, etc.  This special
purpose drive  is made by Seagate.  The print streamer can store up
to 500 4 bp.

PES H/W Controller -

Controls the Xeikon hardware.  Uses its own memory if no print
streamer is connected.  It is 486-based (Industry Standard
Architecture (ISA) bus) chips for faster control.  However, with a
print streamer the PES controller is not a bottleneck.  The PES
interface consists of  1500 variables of which some may be of
relevance while others are of less  significance.

New Proposed Design

Features of New Design
  o  Prints PS, AFP, IPDS, PCL and ASCII.  All non-PS
      jobs are converted to PS using PSF, Axis, and other
      transforms.  Another option  would be to convert all
      jobs to versatile form especially since fast distillation
      of PS to page-independent PS is a reality.
  o  Each Teak3 is directly serviced by a d...