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Browse Prior Art Database

Means to Transform Lines ("Rules") to Improve Printer Performance

IP.com Disclosure Number: IPCOM000102169D
Original Publication Date: 1990-Nov-01
Included in the Prior Art Database: 2005-Mar-17
Document File: 2 page(s) / 67K

Publishing Venue

IBM

Related People

Dollyhite, JD: AUTHOR [+3]

Abstract

An algorithm is disclosed for transforming rules (horizontal and vertical lines) such that optimal printer performance is obtained when printing these rules intermixed with text of a given density.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Means to Transform Lines ("Rules") to Improve Printer Performance

       An algorithm is disclosed for transforming rules
(horizontal and vertical lines) such that optimal printer performance
is obtained when printing these rules intermixed with text of a given
density.

      Many dot matrix printers print in multiple qualities for text.
For a certain dot matrix printer to print in multiple qualities, the
print head is tilted to align the print wires for either high speed
(DP quality) printing or high density (Near Letter Quality) printing.
To tilt the print head, the print head is run across the print line
to strike a "tilt bar" at either the left side frame or the right
side frame.  When printing multiple qualities on the same print line,
the printer must first strike one side frame to tilt the head one way
and print the portion of the line to be printed in the first quality;
then strike the other side frame to tilt the head the opposite way
and print the remaining portion of the line for the second quality.
The tilt operation is essentially unproductive time because the
printer is not printing while the head moves to the tilt target, so
printer throughput is adversely impacted.

      In prior art, the rules referred to above were always printed
in Near Letter Quality (NLQ).  When mixing DP text with these NLQ
rules, performance was degraded due to the impact from tilting the
print head multiple times on each line as discussed above.

      An overview of the disclosed algorithm is as follows:
      1.   When a rule is received by the printer, the dot image
density for the ru...