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Browse Prior Art Database

Carrier Backlash Algorithm

IP.com Disclosure Number: IPCOM000099970D
Original Publication Date: 1990-Mar-01
Included in the Prior Art Database: 2005-Mar-15
Document File: 1 page(s) / 39K

Publishing Venue

IBM

Related People

Do, PK: AUTHOR [+2]

Abstract

Due to inaccuracies of the mechanics which compose the horizontal motion of the print head element, printed dots do not appear in their theoretical positions but are displaced by some factors. The method below will initially and, thereafter, statistically reduce this effect, thus improving print quality.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 81% of the total text.

Carrier Backlash Algorithm

       Due to inaccuracies of the mechanics which compose the
horizontal motion of the print head element, printed dots do not
appear in their theoretical positions but are displaced by some
factors.  The method below will initially and, thereafter,
statistically reduce this effect, thus improving print quality.

      The printer carrier flag length needs to be longer than the
linear distance of the acceleration ramp of the measuring speed.
With such a flag, the following algorithm will determine the system
backlash using the home sense device and a detection mechanism:
   1.   The carrier is commanded to move to the right at least twice
the linear ramp distance of the motor.
   2.   The carrier now moves to the left beyond the ramp distance
into a region of constant velocity, until it trips the sensing
device.  At this point, a counter is started.
   3.   The counter continues to run until the next motor step is
issued.  This count is t1.
   4.   This motor step is marked for future reference, and the
carrier continues to move to the left by at least twice the linear
ramp distance.
   5.   The carrier will be next moved from right to left, and the
time at which the marked motor step is encountered, a counter is
again started.  This counter will continue to run until the sensing
device is again tripped.  This count is t2.
   6.   The difference between t1 and t2 is the backlash count of the
system associated...