Browse Prior Art Database

Nozzle Configuration for a Bubble Jet Print Head

IP.com Disclosure Number: IPCOM000120017D
Original Publication Date: 1991-Mar-01
Included in the Prior Art Database: 2005-Apr-02
Document File: 5 page(s) / 111K

Publishing Venue

IBM

Related People

Helfenberger, CD: AUTHOR [+3]

Abstract

This invention describes a means to minimize the displacement error in a bubble jet matrix print head.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Nozzle Configuration for a Bubble Jet Print Head

      This invention describes a means to minimize the
displacement error in a bubble jet matrix print head.

      In thermal ink jet print heads, it is usually not possible to
fire all of the nozzles at the same time due to power constraints.
Instead, the nozzles are fired in sequential groups.  (In the
following example, there are 10 groups of 16 nozzles fired at a
time.)  Printers with low print head velocity and a small number of
nozzles often use a straight line configuration.  As the number of
nozzles and the print head velocity increases, the nozzle groupings
are typically staggered, as shown in Fig. 5, to offset displacement
errors.  The firing sequence proceeds from top to bottom, or bottom
to top, depending on print head direction of travel. As the print
head velocity continues to increase, variations in speed due to load
changes result in a displacement error. This error is especially
noticeable when printing graphics and is most visible at the boundary
between print head passes.

      Disclosed herein is a nozzle configuration that minimizes the
effect of displacement error due to velocity changes.  This
configuration is shown in Fig. 1 for a 160-nozzle print head.  The
amount of displacement is exaggerated for purposes of illustration.
With this configuration, the displacement error is minimized across a
specific range of print head velocities.

      The firing sequence for this configuration is shown in Fig. 2.
The firing order is reversed depending on the direction of print head
travel.  When printing from left to right, fire line F1 controls
nozzle groups A6 and B6, F2 controls A5 and B5, F3 controls...