Browse Prior Art Database

Ink Jet Stream Outage Detector

IP.com Disclosure Number: IPCOM000118439D
Original Publication Date: 1997-Feb-01
Included in the Prior Art Database: 2005-Apr-01
Document File: 2 page(s) / 57K

Publishing Venue

IBM

Related People

Adams, DJ: AUTHOR [+4]

Abstract

Disclosed is a technique for detecting any ink jet stream outage in any ink jet head. Once an outage is detected, the printhead with the problem receives maintenance and the print job occurring during the outage is reprinted.

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

Ink Jet Stream Outage Detector

      Disclosed is a technique for detecting any ink jet stream
outage in any ink jet head.  Once an outage is detected, the
printhead with the problem receives maintenance and the print job
occurring during  the outage is reprinted.

      The methodology for detecting a missing stream is to have each
ink jet printhead print a solid rectangle between print jobs.  These
rectangles are horizontally scanned to determine the presence of a
white space using a light detection device and monitor.  A swing in
output voltage is associated with a white space or an ink jet stream
outage.  Each printhead prints a test rectangle whose width is
approximately equal to the nozzle array width and whose height is
such that three or four scans can be made of the printed test
rectangle.  The test rectangle(s) can be printed at convenient
locations on the print medium between print jobs.  The scanning of
the rectangle is done as the paper or print medium moves by the light
detection means.  Typically, successive dots are somewhat overlapped
such that the printed test rectangle should be all 'black' if all the
ink jets are operating properly.  A device similar to a bar code
reading gun can be mounted above or near the printheads.

      The detection device (bar code reading gun or equivalent) may
contain a low cost laser whose beam is oscillated across the
rectangle horizontally by an oscillating or rotating mirror.  The
beam can typically oscillate over a...