Incremental printing of symbolic information – Ink jet – Ejector mechanism
Reexamination Certificate
2002-01-23
2002-12-31
Barlow, John (Department: 2853)
Incremental printing of symbolic information
Ink jet
Ejector mechanism
C347S065000
Reexamination Certificate
active
06499835
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates to inkjet printhead structures.
The basic concept of inkjet printing is an ink-firing element having an ink-firing chamber with an orifice for ejecting ink and an ink heating mechanism, generally a resistor, in close proximity to the orifice. In operation, the resistor is quickly heated. The heating transfers a significant amount of energy to the ink, thereby vaporizes a small portion of the ink and produces a bubble in the ink-firing chamber. This in turn creates a pressure wave which propels an ink droplet or droplets from the orifice onto a nearby recording medium such as paper.
Normally, the ink-firing chamber is formed by a semiconductor substrate atop which the resistor rests, an orifice plate which defines the orifice, and a barrier layer sandwiched between the substrate and the orifice plate for supporting the orifice plate. Ink flows from an ink reservoir through an ink refill channel to each ink-firing element. An ink conduit in fluid communication with the ink refill channel is provided in the barrier layer for refilling the ink-firing chamber subsequent to the vaporization process which ejects an ink droplet. The ink conduit is usually formed by creating an open portion in the barrier layer.
The orifice plate, especially if it is a flexible polymer orifice membrane, may sag at the place where the ink conduit exists, since the ink conduit, i.e., an open portion in the barrier layer, provides insufficient support to the part of the orifice plate thereabove. The sag consequently affects the flatness of the orifice plate. Such an effect on the flatness of the orifice plate may cause the orifice to be uncontrollably deformed or tilted thus resulting in inaccurate trajectory of the ink droplets and less than an optimum quality of printing.
Therefore, there is a need for a printhead in which sag of the orifice plate is reduced.
SUMMARY
In an embodiment according to the invention, an ink-firing element includes a resistor for generating ink droplets, a substrate atop which the resistor rests and a barrier layer atop the substrate. The barrier layer is in a closed-loop design and at least partially defines an ink-firing chamber, which surrounds the resistor and temporarily contains ink. The ink-firing element also includes an orifice plate supported by the barrier layer for providing an orifice through which the ink droplets are ejected onto a medium and a trench in the substrate for replenishment of ink. The trench terminates at an outlet in the ink-firing chamber and is in fluid communication with an ink refill channel, which supplies ink from a reservoir to the ink-firing element.
According to an aspect of the invention, a supporter is provided above the trench for supporting a portion of the barrier layer thereabove.
In another embodiment according to the invention, an ink-firing element includes a resistor for generating ink droplets, a substrate atop which the resistor rests, a barrier layer atop the substrate and an orifice plate supported by the barrier layer for providing an orifice through which the ink droplets are ejected onto a medium. The barrier layer partially surrounds the resistor and defines an ink-firing chamber. The ink-firing element also includes an ink conduit provided in the barrier layer for supplying ink from an ink refill channel to the ink-firing chamber. The ink refill channel supplies ink from a reservoir to the ink-firing element. Furthermore, the ink-firing element includes a trench provided in the substrate for supplementary replenishment of ink. The trench is in fluid communication with the ink refill channel and terminates at an outlet in the ink-firing chamber.
In an embodiment of a process for producing an ink-firing element, a supporting layer of a pre-defined pattern is first applied above a substrate atop which a resistor rests for generating ink droplets. The substrate is then etched to form a trench therein, and the trench is in fluid communication with an ink refill channel, which supplies ink from an ink reservoir to the ink-firing element. Subsequently, a barrier layer is attached atop the substrate. The barrier layer at least partially defines an ink-firing chamber and is positioned such that the trench in the substrate terminates at an outlet in the ink-firing chamber. After that, an orifice plate is placed above the barrier layer for providing an orifice through which the ink droplets are ejected onto a medium.
Other aspects and advantages of the invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings, which illustrates by way of example the principles of the invention.
REFERENCES:
patent: 4394670 (1983-07-01), Sugitani et al.
patent: 4688054 (1987-08-01), Inamoto et al.
patent: 4719472 (1988-01-01), Arakawa
patent: 4875968 (1989-10-01), O'Neill et al.
patent: 5017947 (1991-05-01), Masuda
patent: 5387314 (1995-02-01), Baughman et al.
patent: 5463413 (1995-10-01), Ho et al.
patent: 5582678 (1996-12-01), Komuro
patent: 5760803 (1998-06-01), Yamamoto et al.
patent: 5793393 (1998-08-01), Coven
patent: 5808644 (1998-09-01), Imamura et al.
patent: 5912685 (1999-06-01), Raman
patent: 6000787 (1999-12-01), Weber et al.
patent: 6162589 (2000-12-01), Chen et al.
patent: 0177932 (1989-04-01), None
patent: 0534414 (1993-03-01), None
Chee Swee Guan
Chua Sieo Peng Clara
Ng Wan Sin
Sun Jiansan
Barlow John
Stephens Juanita
LandOfFree
Ink delivery system for an inkjet printhead does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Ink delivery system for an inkjet printhead, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Ink delivery system for an inkjet printhead will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2962885