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# First Hammer Fire Pulse Width Modulation

IP.com Disclosure Number: IPCOM000108414D
Original Publication Date: 1992-May-01
Included in the Prior Art Database: 2005-Mar-22
Document File: 1 page(s) / 38K

IBM

## Related People

Poplawski, SM: AUTHOR [+1]

## Abstract

When printing with relatively low mass print hammers, a printing problem know as "first hammer" first occurs. The symptoms are that the printing produced by the first hammer(s) is both light and slightly misregistered. For typical printing the first few hammers fired occur randomly across the print line, thus each of these hammers is "locally" a first hammer fired. The proposed solution is to determine the hammer(s) to be fired first in each line and to adjust both the energy and the fire time by altering the duration and the start time of the hammer fire pulses (Fig. 1). Fig. 2 depicts the most general implementation of the proposed solution. The described logic is inserted following the computations of the nominal Set and Reset times for the hammers that will be applied to the hammer actions in chronological order, i.e.

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First Hammer Fire Pulse Width Modulation

When printing with relatively low mass print hammers, a
printing problem know as "first hammer" first occurs.  The symptoms
are that the printing produced by the first hammer(s) is both light
and slightly misregistered.  For typical printing the first few
hammers fired occur randomly across the print line, thus each of
these hammers is "locally" a first hammer fired.  The proposed
solution is to determine the hammer(s) to be fired first in each line
and to adjust both the energy and the fire time by altering the
duration and the start time of the hammer fire pulses (Fig. 1).  Fig.
2 depicts the most general implementation of the proposed solution.
The described logic is inserted following the computations of the
nominal Set and Reset times for the hammers that will be applied to
the hammer actions in chronological order, i.e., Set (I) occurs
before Set (I + 1).

Disclosed anonymously.