Recorders – Markers and/or driving means therefor – With ink supply to marker
Reexamination Certificate
1997-10-03
2001-08-14
Le, N. (Department: 2861)
Recorders
Markers and/or driving means therefor
With ink supply to marker
C347S007000
Reexamination Certificate
active
06275245
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to printing high quality ink images having the correct amount of ink in each pixel by microfluidic pumping of colored inks onto a receiver.
BACKGROUND OF THE INVENTION
Microfluidic pumping and dispensing of liquid chemical reagents is the subject of three U.S. Pat. Nos. 5,585,069, 5,593,838, and 5,603,351, all assigned to the David Sarnoff Research Center, Inc. The system uses an array of micron sized reservoirs, with connecting microchannels and reaction cells etched into a substrate. Electrokinetic pumps comprising electrically activated electrodes within the capillary microchannels provide the propulsive forces to move the liquid reagents within the system. The electrokinetic pump, which is also known as an electroosmotic pump, has been disclosed by Dasgupta et al., see “Electroosmosis: A Reliable Fluid Propulsion System for Flow Injection Analyses”, Anal. Chem. 66, pp 1792-1798 (1994). The chemical reagent solutions are pumped from a reservoir, mixed in controlled amounts, and them pumped into a bottom array of reaction cells. The array may be decoupled from the assembly and removed for incubation or analysis. When used as a printing device, the chemical reagent solutions are replaced by dispersions of cyan, magenta, and yellow pigment, and the array of reaction cells may be considered a viewable display of picture elements, or pixels, comprising mixtures of pigments having the hue of the pixel in the original scene. When contacted with paper, the capillary force of the paper fibers pulls the dye from the cells and holds it in the paper, thus producing a paper print of the original scene. One problem with this kind of printer is the control of the volume of the liquid inks. An oversupply of ink in one cell can spill over to its neighboring cells, producing undesired ink contamination that leads to image defects on the receiver. If not enough of liquid inks are supplied in a cell, the color densities produced by the cell on a receiver will be lower than the intended color densities, which also degrades image quality on the final print.
SUMMARY OF THE INVENTION
It is an object of the present invention to ensure that the correct amount of ink is delivered to the receiver by a microfluidic printer thereby provide high quality images by microfluidic printing.
It is another object of the present invention to provide a microfluidic printing apparatus that is robust and reliable.
These objects are achieved by a microfluidic printing apparatus comprising:
a) at least one ink reservoir;
b) a structure defining a plurality of chambers arranged so that the chambers form an array with each chamber being arranged to form an ink pixel;
c) a plurality of microchannels connecting the reservoir to a chamber;
d) a plurality of microfluidic pumps each being associated with single microchannel for supplying ink from an ink reservoir through a microchannel for delivery to a particular chamber;
e) means for detecting the ink fluid level in the chambers and producing a signal; and
f) control means for controlling the microfluidic pumps for delivering the correct amount of ink delivered into each chamber and responsive to the fluid level signal for causing the pumps to terminate the delivery of ink.
ADVANTAGES
An advantage of the present invention is the provision of ink volume detection to ensure that the correct amount of ink is delivered to a receiver thereby reducing image defects.
REFERENCES:
patent: 5473350 (1995-12-01), Mader et al.
patent: 5585069 (1996-12-01), Zanzucchi et al.
patent: 5593838 (1997-01-01), Zanzucchi et al.
patent: 5603351 (1997-02-01), Cherukuri et al.
patent: 5611847 (1997-03-01), Guistina et al.
patent: 5682183 (1997-10-01), Wade et al.
patent: 5745128 (1998-04-01), Lam et al.
patent: 5771810 (1998-06-01), Wolcott
patent: 5774136 (1998-06-01), Barbehenn et al.
patent: 5788388 (1998-08-01), Cowger et al.
“Electroosmosis: A Reliable Fluid Propulsion System for Flow Injection Analysis”, by P. Dasgupta, et al., Analytical Chemistry, vol. 66, No. 11, Jun. 1, 1994, pp. 1792-1798.
DeBoer Charles D.
Fassler Werner
Wen Xin
Eastman Kodak Company
Le N.
Nguyen Lamson D.
Owens Raymond L.
LandOfFree
Controlling amount of ink pixels produced by microfluidic... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Controlling amount of ink pixels produced by microfluidic..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Controlling amount of ink pixels produced by microfluidic... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2438036