Image analysis – Applications
Reexamination Certificate
1998-05-15
2001-02-27
Bella, Matthew C. (Department: 2621)
Image analysis
Applications
C382S128000, C382S134000, 36, C356S073000
Reexamination Certificate
active
06195443
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to a manufacturing system using on-line apparatus for determining the homogeneity of a liquid.
BACKGROUND OF THE INVENTION
An organic solvent, a binder resin, and a pigment are combined and milled for use in the charge generation layer in the fabrication of organic photoreceptors. The pigment and binder resin are chosen to optimize their photoelectric properties, but it is not always possible to optimize the dispersion quality of the resulting coating solution. Charge generating solutions that become unstable over time are a common problem in the fabrication of certain organic photoreceptors. Unstable dispersions result in coating defects in the charge generating layer that lower coating yield during the fabrication process. There is a need, which the present invention addresses, for a manufacturing system that can continuously monitor the dispersion quality of the charge generating solution to be able to prevent coating defects by replacing the charge generating solution on the onset of loss of dispersion quality.
One device that may be effectively used as a tool to monitor dispersion quality is a Hele Shaw flow cell. A Hele Shaw flow cell comprises a pair of flat plates narrowly separated from each other by a fixed distance, and held parallel to each other, thereby creating a gap region between the two plates. The Hele Shaw cell is typically dimensioned such that the separation distance between the plates is several orders of magnitude less than the remaining two orthogonal dimensions defined by the planar surface of either of the plates. A further description of the Hele Shaw flow cell may be found in An Introduction to Fluid Dynamics by G. K. Batchelor (Cambridge University Press, 1967)(copies of the title page, pages 222-223 and 604-605 are attached).
At times over the past several years, a number of the co-inventors checked the quality of a charge generating dispersion batch by taking a small sample from the batch to a laboratory located away from the photoreceptor fabrication line, and running the sample through a rectangular Hele Shaw flow cell where a human operator using a microscope viewed the sample flowing through the flow cell. The batch was approved or disapproved for use in Xerox commercial photoreceptors based on the dispersion quality results of the sample. The sample was then typically discarded. A problem with the above described procedure is that manually checking a sample at a laboratory separated from the photoreceptor fabrication line is very inefficient from a manufacturing viewpoint. The present invention addresses this problem.
A flow cytometer for investigating particle constituents in liquids is described in Kosaka et al., U.S. Pat. No. 5,521,699.
SUMMARY OF THE INVENTION
The present invention is accomplished in embodiments by providing a manufacturing system comprising:
(a) a vessel for holding a liquid;
(b) a first member and a second member, each having a flat surface, wherein the flat surface of the first member faces and is spaced from the flat surface of the second member, thereby defining a gap region between the two flat surfaces, wherein a section of the first member is transparent through the thickness of the first member;
(c) a liquid delivery system connected to the vessel and the gap region which delivers the liquid to the gap region and the liquid flows in the gap region in view of the transparent section of the first member;
(d) a camera positioned to view through the transparent section of the first member;
(e) image processing means coupled to the camera for determining the homogeneity of the liquid in the gap region; and
(f) liquid dispensing equipment connected to the liquid delivery system.
In the present invention, at least a portion of the charge generating dispersion is directed to flow through a Hele Shaw cell in the gap region, resulting in a thin, substantially two-dimensional flowing film. The present invention further includes means to evaluate the quality of the charge generating dispersion by observation and analysis of the appearance of the two dimensional flowing dispersion film.
REFERENCES:
patent: 3838926 (1974-10-01), Kato et al.
patent: 5521699 (1996-05-01), Kosaka et al.
patent: 5573721 (1999-08-01), Gillette
patent: 5715047 (1998-02-01), Adamosky
patent: 5786893 (1998-07-01), Fink et al.
patent: 5841884 (1998-11-01), Yamamoto
patent: 5946220 (1999-08-01), Lemelson
patent: 5983120 (1999-11-01), Groner et al.
An Introduction to Fluid Dynamicsby G.K. Batchelor (Cambridge University Press, 1967)(copies of the title page, pp. 222-223 and 604-605 are attached).
Cady Julie A.
Cai Jian
Dunham Robert F.
Errico Mario
Evans Kent J.
Bella Matthew C.
Choobin M
Soong Zosan S.
Xerox Corporation
LandOfFree
System using on-line liquid characterization apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with System using on-line liquid characterization apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and System using on-line liquid characterization apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2604225