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Replaceable Ink Cartridge for Ink Jet Print Head

IP.com Disclosure Number: IPCOM000120898D
Original Publication Date: 1991-Jun-01
Included in the Prior Art Database: 2005-Apr-02
Document File: 4 page(s) / 130K

Publishing Venue

IBM

Related People

Hanna, DW: AUTHOR [+2]

Abstract

Disclosed is a low-cost, customer-replaceable ink cartridge for a thermal ink jet print head. The more expensive parts of an ink jet print head will outlast the ink supply many times over. Ink cartridges distribute the cost of the more expensive parts over several ink refills, thus greatly reducing the cost of printing.

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Replaceable Ink Cartridge for Ink Jet Print Head

      Disclosed is a low-cost, customer-replaceable ink
cartridge for a thermal ink jet print head.  The more expensive parts
of an ink jet print head will outlast the ink supply many times over.
Ink cartridges distribute the cost of the more expensive parts over
several ink refills, thus greatly reducing the cost of printing.

      The replaceable ink cartridge is described by three
illustrations.  Fig. 1 is a cross-section through the ink cartridge.
Fig. 2 is a cross-section through the print head before the ink
cartridge has been inserted.  Fig. 3 is a cross-section through the
print head after the ink cartridge has been inserted.

      In Fig. 1, the ink cartridge consists of a shell 1 molded of
polyphenylene ether, or some other suitable chemically resistant
polymer.  The shell is filled with an open-cell polyurethane foam 2,
which contains the ink.  The cartridge is closed by a lid 3 molded of
the same material as the cartridge shell.  The lid is ultrasonically
bonded, or otherwise joined, to the shell.  The lid has a vent hole 4
to allow the depleted ink to be displaced with air during printing.
The lid also has ribs 5 projecting downward to hold the foam down and
allow air to reach the entire top surface of the foam.

      In the bottom of the ink cartridge is a circular opening 6 to
receive a projecting part of the print head body.  This will be
described in greater detail later.  The foam contains enough ink so
as to be slightly less than saturated.  The cell size of the foam and
the surface tension of the ink are such that no free ink will run out
of the cartridge until the foam is compressed.  The opening in the
bottom of the cartridge and the vent hole may be covered by a piece
of adhesive-backed tape to prevent evaporation and contamination
before use.

      In Fig. 2, the body of the print head contains a drop generator
chip 7 with its nozzle plate bonded to it.  An electrical interface
is made to the drop generat...