Incremental printing of symbolic information – Ink jet – Fluid or fluid source handling means
Reexamination Certificate
1999-04-08
2001-03-20
Le, N. (Department: 2861)
Incremental printing of symbolic information
Ink jet
Fluid or fluid source handling means
Reexamination Certificate
active
06203150
ABSTRACT:
This invention relates to apparatus and method for collecting liquids and, in particular, to liquid collection apparatus and methods of the type employed in printing devices to collect unused ink.
Traditional liquid collection devices collect liquid (in the case of printing, ink) for reuse in the process in which the liquid is being employed. Such liquid collection devices do, however, have problems associated with them.
One significant problem is that air can be collected with the liquid and mixed with it by the collection device. The air can contain contaminants, which are drawn into the liquid, reducing the quality of the recycled liquid. A further problem, particular to printing inks, is that mixing of the inks with air can lead to ink solvent evaporation into the air, increasing the viscosity of the ink.
The present invention is directed towards the provision of a liquid collection apparatus which collects liquid without collecting air trapped therein.
According to the present invention there is provided a liquid collection apparatus comprising:
means for collecting liquid;
liquid conduit means for transferring liquid from the liquid collection means;
porous liquid absorption means positioned between the liquid collection means and the liquid conduit; and
pump means for pumping liquid from the liquid conduit, the pump means generating a pressure in liquid in the conduit that is sufficient to draw liquid through liquid collection means but is insufficient to draw a gas/liquid surface through the liquid absorption means.
Because the pressure generated by the pump means is not sufficient to draw a gas/liquid surface through the porous liquid absorption means against surface tension forces in the absorption means, any gas contained within the liquid will not be drawn through the liquid absorption means and into the liquid conduit.
The apparatus may be arranged to be employed in an ink jet printhead, in which case the liquid may be ink. The liquid absorption means may have pores of a diameter of one micron or less. The pore diameters may be in the range of 0.2 to 1 micron. Alternatively, it may be formed from a plurality of narrow capillaries.
The material from which the liquid absorption means is formed will be dependent upon the type of liquid being collected, but may formed from cellulose, nylon, mixed esters, or polypropylene.
The liquid collecting means may be arranged so that the surface of the liquid absorption means is not in direct contact with the atmosphere, to reduce the possibility of liquid retained by the absorption means drying due to contact with the atmosphere. The liquid collection means may be formed from a plurality of ribs or of an absorbent material containing pores/capillaries of larger diameter than those in the liquid absorption means. Such an arrangement provides an apparatus which can be moved without liquid spilling out due to the effects of the motion and/or gravity.
According to the present invention there is also provided a method of collecting liquid, the method comprising the steps of:
collecting liquid in a liquid collection means; and
drawing the liquid through a porous liquid absorption means at a pressure level which ensures liquid flow through the liquid collection means yet which is insufficient to draw liquid through the liquid absorption means.
REFERENCES:
patent: 4023182 (1977-05-01), Arway et al.
patent: 4418352 (1983-11-01), Horike et al.
patent: 4476472 (1984-10-01), Aiba et al.
patent: 4586058 (1986-04-01), Yamazaki et al.
patent: 5614929 (1997-03-01), Dangelo et al.
patent: 597 674 (1994-05-01), None
patent: 62-113559 (1987-05-01), None
patent: 98/16390 (1998-04-01), None
Denne William Anthony
Mitchell Richard Frank
Zaba Jerzy Marcin
Conte Robert F. I.
Domino Printing Sciences PLC
Le N.
Lee Mann Smith McWilliams Sweeney & Ohlson
Nghiem Michael
LandOfFree
Liquid collection does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Liquid collection, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Liquid collection will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2440601