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Browse Prior Art Database

Ribbon-Control Method for Improved Print Quality

IP.com Disclosure Number: IPCOM000105576D
Original Publication Date: 1993-Aug-01
Included in the Prior Art Database: 2005-Mar-20
Document File: 2 page(s) / 64K

Publishing Venue

IBM

Related People

Arai, A: AUTHOR [+3]

Abstract

Described is a ribbon control method to improve print density variations occurring in bi-directional printing. In conventional mechanism motions of Serial Impact Printers, the ribbon direction is always in one direction independent of the printing direction. In this conventional method, print density tends to vary for every other line. The New ribbon control method presented below is very effective in solving this problem.

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This is the abbreviated version, containing approximately 68% of the total text.

Ribbon-Control Method for Improved Print Quality

      Described is a ribbon control method to improve print density
variations occurring in bi-directional printing.  In conventional
mechanism motions of Serial Impact Printers, the ribbon direction is
always in one direction independent of the printing direction.  In
this conventional method, print density tends to vary for every other
line.  The New ribbon control method presented below is very
effective in solving this problem.

      To improve print density variations, the ribbon direction must
move the same as the printing direction.  Fig. 1 shows a ribbon shift
mechanism with a layered ink ribbon cartridge that can reverse the
ribbon direction for each line.  The ribbon direction can be switched
during acceleration and deceleration of carriage motion by shifting
up or down of the ribbon cartridge.  When a carriage moves to the
right, the ribbon must be wound up in the same direction, and when
the carriage direction changes to the left, the ribbon cartridge is
shifted to another stair which winds up the ribbon to the left.  The
velocity of these ribbons in the layered cartridge must be the same
to get the same print density.

      There would be some way to implement this ribbon control
through mechanical design.  For example, it is easily realized by
using three stepping motors and two conventional ribbon cartridges
layered.  One motor drives the ribbon shift motion, the others wind
up the ribbon...