Browse Prior Art Database

Optimizing Throughput on Complex Datastream for a Serial Line Printer With Printing Limitations

IP.com Disclosure Number: IPCOM000034911D
Original Publication Date: 1989-May-01
Included in the Prior Art Database: 2005-Jan-27
Document File: 2 page(s) / 14K

Publishing Venue

IBM

Related People

Badani, HN: AUTHOR [+5]

Abstract

Disclosed is a method that allows complex data streams to be printed in a smaller number of continuous horizontal sweeps rather than a greater number of short sweeps. Serial line printers processing complex host data streams that perform such functions as justified text, multiple font changes on a line, or APA and text on the same line, often perform these at a much lower throughput than the standard texts used to measure throughput for marketing claims. This has led in the past to negative customer impressions and unusable systems for certain applications. The method described allows complex data streams to be processed prior to printing in a manner that allows most complex lines to be processed before the previous line is completed.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 55% of the total text.

Page 1 of 2

Optimizing Throughput on Complex Datastream for a Serial Line Printer With Printing Limitations

Disclosed is a method that allows complex data streams to be printed in a smaller number of continuous horizontal sweeps rather than a greater number of short sweeps. Serial line printers processing complex host data streams that perform such functions as justified text, multiple font changes on a line, or APA and text on the same line, often perform these at a much lower throughput than the standard texts used to measure throughput for marketing claims. This has led in the past to negative customer impressions and unusable systems for certain applications. The method described allows complex data streams to be processed prior to printing in a manner that allows most complex lines to be processed before the previous line is completed. This allows carrier movement to be extended for a printing line to be set up for the next line to print, minimizing carrier start/stops that decrease throughput. Also, some matrix printer technologies have printing limitations such as printhead frequency limitations, printhead thermal limitations, or power supply energy limitations that must be designed around. Many printers limit the data patterns that can be printed or stop printing when limitation is reached and then restart the print operation. Limiting the possible print patterns decreases the usability and limits the application of the printer. Stopping and restarting the printer can severely affect throughput. The method centers buffers processing using the buffers described in the drawing where: Host Data Buffer

- The Host Data Buffer contains the datastream sent

by the host that is supported by the printer.

Line Image Buffer

- The Line Image Buffer contains the bit image data

of the print pass of the next line to be printed.

The data is stored in the print resolution of that

next print pass in a vertical swath equal to the

print elements in the printhead.

Print Image Buffer

- The Print Image Buffer contains the bit image data

of the print pass of the line that is printing.

The data is stored in the print resolution of that

print pass in a vertical swath equal to the print

elements in the printhead. As data is moved to

the wire image it is removed from the Print Image

Buffer. Wire Image Buffer

- The Wire Image Buffer contains the bit image data

of the print pass that is printable in this pass. The text and data from the host is stored in the Host Buffer. The data is processed and bit image data representing the characters or APA to be printed in the next print pass is stored in the line image buffer.

The Line Image Buf...