Browse Prior Art Database

Improved Wire Printer Bi-Directional Print Quality

IP.com Disclosure Number: IPCOM000103090D
Original Publication Date: 1990-Jun-01
Included in the Prior Art Database: 2005-Mar-17
Document File: 1 page(s) / 37K

Publishing Venue

IBM

Related People

Do, PK: AUTHOR [+5]

Abstract

Disclosed is a means for improving wire printer print quality permitting bi-directional NLQ (near letter quality) printing.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 100% of the total text.

Improved Wire Printer Bi-Directional Print Quality

      Disclosed is a means for improving wire printer print quality
permitting bi-directional NLQ (near letter quality) printing.

      NLQ printing on a wire printer is most commonly accomplished by
printing in two uni-directional passes. This is because minor errors
in dot placement when reverse printing, relative to dot placement
when forward printing, due to backlash and other mechanical aspects
of the drive system, preclude bi-directional NLQ printing.

      The present embodiment is based on the fact that most of the
dot placement error when reverse printing is caused by mechanical
factors that are sufficiently consistent and constant, for extended
time periods, to facilitate compensation.  The error is compensated
for by shifting the dot printing time when reverse printing, thus
permitting the second pass for NLQ printing to be accomplished in the
reverse direction.

      Since this type of error can vary from machine to machine, and
over the life of a machine, the present embodiment provides a menu of
patterns of incremental horizontal dot registration which are invoked
via the operator panel.  Initial tests are run with various patterns
to determine that which produces best results for that machine.  The
result is stored in machine memory for future reference.

      Disclosed anonymously.