Browse Prior Art Database

Font Improvement through Double Strike

IP.com Disclosure Number: IPCOM000117092D
Original Publication Date: 1995-Dec-01
Included in the Prior Art Database: 2005-Mar-31
Document File: 2 page(s) / 40K

Publishing Venue

IBM

Related People

Zable, JL: AUTHOR

Abstract

In impact matrix printers, many character fonts could be improved if two adjacent dots could be located closer than one pel apart. Thus, if two adjacent dots could be located at a distance of, say 1/2 a pel apart, improved fonts would occur. An example of this is shown in the Figure for the character N. The character N, printed on the left side is four dots wide which is typical for the normal quality mode for matrix printers. Additionally, it can be seen that there are no adjacent dots that are closer than a distance of one pel apart. This is a general requirement, since a distance of one pel, typically corresponds to the fastest hammer firing repetition time.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 88% of the total text.

Font Improvement through Double Strike

      In impact matrix printers, many character fonts could be
improved if two adjacent dots could be located closer than one pel
apart.  Thus, if two adjacent dots could be located at a distance of,
say 1/2 a pel apart, improved fonts would occur.  An example of this
is shown in the Figure for the character N.  The character N, printed
on the left side is four dots wide which is typical for the normal
quality mode for matrix printers.  Additionally, it can be seen that
there are no adjacent dots that are closer than a distance of one pel
apart.  This is a general requirement, since a distance of one pel,
typically corresponds to the fastest hammer firing repetition time.
Typically when a print hammer is fired at a repetition rate somewhat
faster than this time, the print hammer will not be able to respond
to input pulsing and will not fire, causing missing dots.

      However, if only two hammer fires are required that correspond
to a distance closer than one pel, even as close as 1/2 pel, the
print hammer can function.  Even though the impact force for the
second impact is significantly lower than that for the first impact,
the second dot will still have a reasonable print density and dot
size.  There is minor misregistration of the second dot.  Repetitive
firing of this two pulse scheme at rated rep rate shows no
degradation of the force levels.  Thus, in the Figure, the N printed
to the right has two dots, dots 1...