U.S. patent application number 10/858464 was filed with the patent office on 2004-11-11 for system and method for compensating for non-functional ink cartridge ink jet nozzles.
Invention is credited to Bayramoglu, Gokalp, Crisler, Curtis L., D'souza, Henry M..
Application Number | 20040223025 10/858464 |
Document ID | / |
Family ID | 22896319 |
Filed Date | 2004-11-11 |
United States Patent
Application |
20040223025 |
Kind Code |
A1 |
D'souza, Henry M. ; et
al. |
November 11, 2004 |
System and method for compensating for non-functional ink cartridge
ink jet nozzles
Abstract
A system for compensating for non-functional ink cartridge ink
jet nozzles is provided. The system includes an ink jet
compensation system that receives ink jet nozzle failure data, such
as each nozzle that is clogged or damaged, and that generates
nozzle correction data, such as a nozzle to fire instead of each
failed nozzle for a given print pattern or a nozzle firing sequence
that compensates for the failed nozzle, such as by printing at that
location during a subsequent or previous printer head pass. An ink
control system receives the nozzle correction data and image data
and generates printer control data, such as by receiving image data
in a standard format for printing and modifying the printer control
data that would be generated if all ink jet heads were functioning
properly to include the nozzle correction data.
Inventors: |
D'souza, Henry M.; (Cypress,
TX) ; Crisler, Curtis L.; (Cypress, TX) ;
Bayramoglu, Gokalp; (Houston, TX) |
Correspondence
Address: |
HEWLETT-PACKARD COMPANY
Intellectual Property Administration
P.O. Box 272400
Fort Collins
CO
80527-2400
US
|
Family ID: |
22896319 |
Appl. No.: |
10/858464 |
Filed: |
June 1, 2004 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
10858464 |
Jun 1, 2004 |
|
|
|
09238056 |
Jan 27, 1999 |
|
|
|
6000645 |
|
|
|
|
Current U.S.
Class: |
347/19 |
Current CPC
Class: |
B03B 9/063 20130101;
Y02W 30/58 20150501; Y02W 30/52 20150501; B07B 1/22 20130101; Y02W
30/523 20150501 |
Class at
Publication: |
347/019 |
International
Class: |
B41J 029/393 |
Claims
1. An ink jet printer system comprising: an ink jet printer having
a carriage adapted to hold at least one ink jet cartridge having a
plurality of ink jet nozzles; and a printer driver adapted to
transmit image data and control commands to the ink jet printer,
the printer driver adapted to process data correlative to any
non-functional ink jet nozzles on the at least one ink jet
cartridge to generate the control commands, the control commands
adapted to control the ink jet printer to print an image
correlative to the image data using only functional ink jet nozzles
on the at least one ink jet cartridge.
2. The printer system of claim 1, wherein the printer driver
comprises an ink jet compensation system having a nozzle correction
pattern system adapted to receive nozzle failure data and generate
nozzle correction pattern data.
3. The printer system of claim 1, wherein the printer driver
comprises an ink jet compensation system having a nozzle control
sequence system adapted to receive nozzle failure data and generate
nozzle control sequence data.
4. The printer system of claim 1, comprising at least one ink jet
cartridge, the at least one ink jet cartridge having stored therein
the data correlative to any non-functional ink jet nozzles on the
at least one ink jet cartridge, the data being retrievable by the
printer driver.
5. The printer system of claim 4, wherein the at least one ink jet
cartridge comprises a cartridge memory adapted to store the data
correlative to any non-functional ink jet nozzles on the at least
one ink jet cartridge.
6. The printer system of claim 1, wherein the printer driver
comprises an index interface system adapted to receive data
identifying the at least one ink jet cartridge and to retrieve data
correlative to any non-functional ink jet nozzles on the at least
one inkjet cartridge based on data identifying the at least one ink
jet cartridge.
7. A method of manufacturing an ink jet cartridge having ink jet
nozzles, comprising the acts of: identifying one or more
non-functional ink jet nozzles of the ink jet cartridge; and
programming the ink jet cartridge to use one or more functional ink
jet nozzles of the ink jet cartridge instead of the non-functional
ink jet nozzles.
8. The method of claim 7, wherein the act of programming comprises
the act of: storing non-functional ink jet nozzle data in a memory
of the ink jet cartridge.
9. The method of claim 7, wherein the act of programming comprises
the act of: programming the ink jet cartridge to use functional ink
jet nozzles of the ink jet cartridge in one or more predetermined
ink jet nozzle fire patterns.
10. The method of claim 7, wherein the act of programming comprises
the act of: programming the ink jet cartridge to use functional ink
jet nozzles of the ink jet cartridge in one or more predetermined
ink jet nozzle fire sequences.
11. A printer driver, comprising: a tangible medium having stored
thereon code adapted to transmit image data and control commands to
an ink jet printer, the printer driver adapted to process data
correlative to any non-functional inkjet nozzles on an inkjet
cartridge associated with the ink jet printer to generate the
control commands, the control commands adapted to control the ink
jet printer to print an image correlative to the image data using
only functional ink jet nozzles on the ink jet cartridge.
12. The printer driver of claim 11, wherein the code comprises an
ink jet compensation system having a nozzle correction pattern
system adapted to receive nozzle failure data and generate nozzle
correction pattern data.
13. The printer driver of claim 11, wherein the code comprises an
ink jet compensation system having a nozzle control sequence system
adapted to receive nozzle failure data and generate nozzle control
sequence data.
14. The printer driver of claim 11, comprising code adapted to
retrieve the data correlative to any non-functional ink jet nozzles
from a cartridge memory on the ink jet cartridge.
15. The printer driver of claim 11, comprising code adapted to
receive data identifying the ink jet cartridge and to retrieve the
data correlative to any non-functional ink jet nozzles from a
database based on the data identifying the ink jet cartridge.
16. A computer system, comprising: a computer having a printer
driver stored in memory, the printer driver comprising: code
adapted to transmit image data and control commands to an ink jet
printer, the printer driver adapted to process data correlative to
any non-functional ink jet nozzles on an ink jet cartridge
associated with the ink jet printer to generate the control
commands, the control commands adapted to control the ink jet
printer to print an image correlative to the image data using only
functional ink jet nozzles on the ink jet cartridge.
17. The computer system of claim 16, wherein the code comprises an
ink jet compensation system having a nozzle correction pattern
system adapted to receive nozzle failure data and generate nozzle
correction pattern data.
18. The computer system of claim 16, wherein the code comprises an
ink jet compensation system having a nozzle control sequence system
adapted to receive nozzle failure data and generate nozzle control
sequence data.
19. The computer system of claim 16, comprising code adapted to
retrieve the data correlative to any non-functional ink jet nozzles
from a cartridge memory on the ink jet cartridge.
20. The computer system of claim 16, comprising code adapted to
receive data identifying the ink jet cartridge and to retrieve the
data correlative to any non-functional ink jet nozzles from a
database based on the data identifying the ink jet cartridge.
21. An ink jet cartridge having ink jet nozzles, comprising: a
memory device; and data stored on the memory device, wherein the
data comprises at least one of non-functional nozzle data and
nozzle correction data.
22. The ink jet cartridge of claim 21, wherein the nozzle
correction data comprises at least one of nozzle correction pattern
data and nozzle control sequence data.
23. The inkjet cartridge of claim 21, wherein the nozzle correction
data is generated by an ink jet compensation system that receives
non-functional nozzle data.
24. The ink jet cartridge of claim 21, wherein the data stored on
the memory device comprises cartridge identification data.
25. A method of using an ink jet printer, comprising the acts of:
processing data correlative to one or more non-functional ink jet
nozzles of an ink jet cartridge to generate nozzle correction data;
and controlling one or more functional ink jet nozzles of the ink
jet cartridge to compensate for the non-functional ink jet nozzles
in response to the nozzle correction data.
26. The method of claim 25, comprising the acts of: receiving
identification data correlative to the ink jet cartridge; and
retrieving the data correlative to the one or more non-functional
ink jet nozzles of the ink jet cartridge from a remote
location.
27. The method of claim 26, wherein the identification data is
input by a user.
28. The method of claim 26, wherein the identification data is
received from a data storage device of the ink jet cartridge.
29. The method of claim 25, comprising the act of: retrieving the
data correlative to the one or more non-functional ink jet nozzles
from a data storage device of the ink jet cartridge.
30. A test system, comprising: an ink jet cartridge test system
adapted to identify non-functional ink jet nozzles of an ink jet
cartridge and to store data correlative to any identified
non-functional ink jet nozzles in one of a memory device on the ink
jet cartridge and a database adapted to store data correlative to a
plurality of ink jet cartridges.
31. The test system of claim 30, wherein the data correlative to
any identified non-functional ink jet nozzles is utilized to
generate nozzle correction data.
32. The test system of claim 31, wherein the nozzle correction data
comprises at least one of nozzle correction patterns and nozzle
control sequences.
33. The test system of claim 30, wherein the ink jet test system is
adapted to generate a sequence of test images using the ink jet
nozzles of the ink jet cartridge and to compare the generated
sequence of test images with sample images to identify any
non-functional nozzles of the ink jet cartridge.
34. An apparatus, comprising: means for identifying one or more
non-functional ink jet nozzles of the ink jet cartridge; and means
for programming the ink jet cartridge to use one or more functional
ink jet nozzles of the ink jet cartridge instead of the
non-functional ink jet nozzles.
35. An apparatus, comprising: means for transmitting image data and
control commands to an ink jet printer; means for processing data
correlative to any non-functional ink jet nozzles on an ink jet
cartridge associated with the ink jet printer to generate the
control commands; and means for controlling the ink jet printer
responsive to the control commands to print an image correlative to
the image data using only functional ink jet nozzles on the ink jet
cartridge.
36. An apparatus, comprising: means for processing data correlative
to one or more non-functional ink jet nozzles of an ink jet
cartridge to generate nozzle correction data; and means for
controlling one or more functional ink jet nozzles of the ink jet
cartridge to compensate for the non-functional ink jet nozzles in
response to the nozzle correction data.
37. A test system, comprising: means for identifying non-functional
ink jet nozzles of an ink jet cartridge; means for storing data
correlative to any identified non-functional ink jet nozzles in one
of a memory device on the ink jet cartridge and a database adapted
to store data correlative to a plurality of ink jet cartridges.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is related to co-pending and commonly owned
application Ser. No. 09/822,094, filed Mar. 30, 2001, entitled
"Automatic Printer Color Correction Based on Characterization Data
of a Color Ink Cartridge;" and to application Ser. No. 10/184,468,
filed Jun. 27, 2002, entitled "Method and System for Controlling
Printer Color;" and to application Ser. No. 10/185,807, filed Jun.
27, 2002, entitled "Method and System for Characterizing Printer
Color," each of which are hereby incorporated by reference in their
entirety for all purposes.
STATEMENTS REGARDING FEDERALLY SPONSORED RESEARCH OR
DEVELOPMENT
[0002] Not applicable.
REFERENCE TO A MICROFICHE APPENDIX
[0003] Not applicable.
BACKGROUND OF THE INVENTION
[0004] 1. Field of the Invention
[0005] The present invention generally relates to ink cartridge
control and more particularly to determining ink jet nozzle control
data for an ink cartridge that can be used to compensate for
non-functional ink jet nozzles.
[0006] 2. Description of the Related Art
[0007] An ink jet ink cartridge includes a number of ink jet
nozzles that are fired in a predetermined pattern in response to
image data to generate an image. The predetermined pattern takes
into account that each ink jet nozzle is not fired on every pass,
and that the ink jet nozzle array can pass over the same location
more than once. The printer driver of a personal computer receives
image data in a standard format and generates printer control data
based on the number of nozzles in the ink cartridge and other ink
cartridge parameters.
[0008] If one or more ink jet nozzles of an ink cartridge are
non-functional, such as because of damage or clogging, then the
image quality generated by that ink cartridge will suffer from
level of image quality degradation. This image quality degradation
may or may not be noticeable to the human eye. As a result of this
image quality degradation, ink cartridge manufacturers and others
set levels for an acceptable number and density of non-functional
ink jet nozzles for a given ink cartridge. If the number of
non-functional ink jet nozzles exceeds this predetermined number,
then the ink cartridge is not used, which decreases ink cartridge
yield rates and drives up the cost of manufacturing ink
cartridges.
SUMMARY OF THE INVENTION
[0009] In accordance with the present invention, a system and
method for compensating for non-functional ink cartridge ink jet
nozzles or other suitable print mechanisms are provided that
overcome known problems with non-functional ink jet nozzles.
[0010] In particular, a system and method for compensating for
non-functional ink cartridge ink jet nozzles are disclosed that use
other functional ink jet nozzles of the ink cartridge instead of
the non-functional nozzle in order to allow ink cartridges that
would otherwise be discarded to be used, thereby increasing ink
cartridge yield rates.
[0011] In accordance with an exemplary embodiment of the present
invention, a system for compensating for non-functional ink
cartridge ink jet nozzles is provided. The system includes an ink
jet compensation system that receives ink jet nozzle failure data,
such as the coordinates of each nozzle that is clogged or damaged,
and that generates nozzle correction data, such as a nozzle to fire
instead of each failed nozzle for a given print pattern or a nozzle
firing sequence that compensates for the failed nozzle, such as by
printing at the location of the failed nozzle during a subsequent
or previous printer head pass. An ink control system receives the
nozzle correction data and image data and generates printer control
data, such as by receiving image data in a standard format for
printing and modifying the printer control data that would be
generated if all ink jet heads were functioning properly to include
the nozzle correction data.
[0012] The present invention provides many important technical
advantages. One important technical advantage is a system for
compensating for non-functional ink cartridge ink jet nozzles that
uses functional ink jet nozzles to compensate for non-functional
ink jet nozzles, such as by firing an adjacent functional nozzle
instead of a non-functional nozzle, or by firing a functional
nozzle during a previous or subsequent printer head pass so as to
print in the location that the non-functional ink jet nozzle would
have printed. The present invention thus allows ink jet nozzle
failure data for each ink cartridge to be generated and used to
compensate for the non-functional ink jet nozzles, thereby
increasing ink cartridge yield.
[0013] Those skilled in the art will further appreciate the
advantages and superior features of the invention together with
other important aspects thereof on reading the detailed description
that follows in conjunction with the drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0014] A better understanding of the present invention can be
obtained when the following detailed description of the preferred
embodiment is considered in conjunction with the following
drawings, in which:
[0015] FIG. 1 is a diagram of a system for providing color
characterization and color control, including compensation for
non-functional ink jet nozzles or other suitable printing
mechanisms, in accordance with an exemplary embodiment of the
present invention;
[0016] FIG. 2 is a diagram of a system for providing camera
calibration in accordance with an exemplary embodiment of the
present invention;
[0017] FIG. 3 is diagram of a system for performing color indexing
in accordance with an exemplary embodiment of the present
invention;
[0018] FIG. 4 is a diagram of a system for index interfacing in
accordance with an exemplary embodiment of the present
invention;
[0019] FIG. 5 is a diagram of a system for controlling a color
cartridge in accordance with an exemplary embodiment of the present
invention;
[0020] FIG. 6 is a flowchart of a method for providing compensation
for non-functional ink cartridge ink jet nozzles in accordance with
an exemplary embodiment of the present invention;
[0021] FIG. 7 is a flowchart of a method for generating nozzle
correction pattern data and nozzle control sequence data in
accordance with an exemplary embodiment of the present
invention;
[0022] FIG. 8 is a flowchart of a method for determining whether a
nozzle correction pattern or nozzle control sequence for a
non-functioning ink jet nozzle is acceptable in accordance with an
exemplary embodiment of the present invention;
[0023] FIG. 9 is a diagram of non-functional ink jet nozzle
patterns in accordance with an exemplary embodiment of the present
invention;
[0024] FIG. 10 is a diagram of a system for providing ink jet head
analysis in accordance with an exemplary embodiment of the present
invention; and
[0025] FIG. 11 is a diagram of a system for ink jet nozzle
compensation in accordance with an exemplary embodiment of the
present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0026] In the description that follows, like parts are marked
throughout the specification and drawings with the same reference
numerals, respectively. The drawing figures might not be to scale
and certain components can be shown in generalized or schematic
form and identified by commercial designations in the interest of
clarity and conciseness.
[0027] FIG. 1 is a diagram of a system 100 for providing color
characterization and color control, including compensation for
non-functional ink jet nozzles or other suitable printing
mechanisms, in accordance with an exemplary embodiment of the
present invention. System 100 allows the color density generated
for a corresponding dot activation for a specimen ink cartridge to
be characterized as part of the manufacturing process, such that
the color characterization data can be accessed when the cartridge
is installed for use, and further maps the specimen ink cartridge
data to reference ink cartridge data, so as to generate printer
control data that activates the correct dot percentage to generate
a desired color density. System 100 can also be used with other
suitable methods and systems for generating color density, such as
those that do not use dot activation.
[0028] System 100 includes ink characterization system 102 and ink
correction system 104, each of which can be implemented in
hardware, software, or a suitable combination of hardware and
software, and which can be one or more hardware systems, or one or
more software systems operating on a general purpose processing
platform. As used herein, a hardware system can include discrete
semiconductor devices, an application-specific integrated circuit,
a field programmable gate array or other suitable devices. A
software system can include one or more objects, agents, threads,
lines of code, subroutines, separate software applications,
user-readable (source) code, machine-readable (object) code, two or
more lines of code in two or more corresponding software
applications, databases, or other suitable software architectures.
In one exemplary embodiment, a software system can include one or
more lines of code in a general purpose software application, such
as an operating system, and one or more lines of code in a specific
purpose software application. A software system can be stored on
hard drive 124, and retrieved by microprocessor 120 for operation
in conjunction with non-volatile memory device 122, user input
device 118, printer 126, and monitor 116. In this exemplary
embodiment, a software system can include a printer driver, a
monitor driver, a camera driver, or other suitable software
systems.
[0029] Ink characterization system 102 is coupled to ink correction
system 104 by communications medium 114. As used herein, the term
"couple" and its cognate terms, such as "couples" and "coupled,"
can include a physical connection (such as a copper conductor), a
virtual connection (such as through randomly assigned memory
locations of a data memory device), a logical connection (such as
through logical gates of a semiconducting device), other suitable
connections, or a suitable combination of such connections. In one
exemplary embodiment, systems and components are coupled to other
systems and components through intervening systems and components,
such as through an operating system. Communications medium 114 can
be a local area network, a wide area network, a public network such
as the Internet, the public switched telephone network, a wireless
network, a fiber optic network, other suitable media, or a suitable
combination of such media.
[0030] Ink characterization system 102 provides ink
characterization data to ink correction system 104, such as when a
user of ink correction system 104 installs a new cartridge, by
storing the ink characterization data on the cartridge, or in other
suitable manners. Ink characterization system 102 includes camera
calibration system 106, color indexing system 108, ink jet test
system 128, and head analysis system 130, each of which can be
implemented in hardware, software, or a suitable combination of
hardware and software, and which can be one or more software
systems operating on a general purpose processing platform.
[0031] Camera calibration system 106 is used to calibrate a video
camera so that it can be used to provide color characterization
data. In the past, calorimeters, spectrophotometers, or other
specialized devices were required in order to obtain a precise
estimate of the color of printed ink. Camera calibration system 106
performs calibration of video cameras having standard color pixel
arrays with pixel filters so that high speed video cameras can be
used to perform color characterization.
[0032] Color indexing system 108 receives the color
characterization data for a specimen ink cartridge and stores it in
a relational database so it can be retrieved at a later date. In
addition, color indexing system 108 stores reference ink cartridge
color characterization data and associated reference ink cartridge
identification data with specimen ink cartridge data. In this
manner, color indexing system 108 allows reference ink cartridge
data and specimen ink cartridge data to be provided on demand, to
be stored on a cartridge for transmission to the user, or in other
suitable manners.
[0033] Ink correction system 104 includes index interface system
110 and cartridge correction system 112, each of which can be
implemented in hardware, software, or a suitable combination of
hardware and software, and which can be one or more software
systems operating on a general purpose processing platform. Index
interface system 110 retrieves the specimen ink cartridge color
characterization data and the reference ink cartridge color
characterization data, such as by contacting color indexing system
108 over communications medium 114, by retrieving the data from a
data storage device of the ink cartridge, or in other suitable
manners. Index interface system 110 then provides the data to
cartridge correction system 112, which generates color correction
factors from the specimen ink cartridge color characterization data
and the reference ink cartridge color characterization data to be
used for controlling printing. Cartridge correction system 112 can
also receive other suitable data from ink characterization system
102 for controlling the quality of the color, such as empirical
scale factors. In another exemplary embodiment, index interface
system 110 retrieves non-functional ink jet nozzle identification
data, nozzle correction pattern data, nozzle control sequence data,
or other suitable data from ink jet test system 128, head analysis
system 130, or other suitable systems, and provides the data to
cartridge correction system 112 for use in correcting an ink
cartridge for non-functional ink jet nozzles or other
conditions.
[0034] Ink jet test system 128 performs ink cartridge ink jet
nozzle test processes in accordance with an exemplary embodiment of
the present invention. Ink jet test system 128 can print two or
more ink jet nozzle test patterns that can be subsequently analyzed
to determine which, if any, of the ink jet nozzles are
non-functional, such as due to clogging, damage, or other problems.
In one exemplary embodiment, ink jet test system 128 can generate a
sequence of patterns, such as patterns in which alternating rows of
nozzles are activated, patterns that are configured to allow image
data to be readily analyzed to detect non-functional ink jet
nozzles, or other suitable patterns. In another exemplary
embodiment, ink jet test system 128 can generate a sequence of
nozzle correction patterns and nozzle control sequence images that
can be analyzed to determine whether the nozzle correction patterns
or nozzle control sequences can be used to compensate for
non-functional ink jet nozzles. In this exemplary embodiment, ink
jet test system 128 can receive non-functional nozzle
identification data and can generate a first sequence of test
patterns for activation of the ink cartridge with different ink jet
nozzles activated in place of the non-functional ink jet nozzle,
such as to allow the patterns to be compared to a reference image
for determination of color density similarity, image data
similarity, for comparison of image data generated by a camera or
other device that simulates the human viewing capabilities, or
other suitable tests.
[0035] Likewise, ink jet test system 128 can generate a sequence of
test images whereby the non-functional ink jet nozzle function is
compensated for by firing other ink jet nozzles during a previous
or subsequent pass of the printer head. For example, an ink jet
printer head typically prints by activating certain nozzles in a
forward pass while allowing other nozzles to remain inactive, and
by activating the other nozzles in a reverse pass while allowing
the forward pass nozzles to remain inactive. In this manner,
problems caused by nozzle overheating can be minimized. Likewise,
the ink jet head can pass over a given point at least four times,
depending on the printing speed and resolution--twice in a forward
direction and twice in a returning direction. Thus, the point at
which a non-functional nozzle should have printed might be
accessible by another functional nozzle in a previous or subsequent
pass, either in the forward or reverse direction. Ink jet test
system 128 generates test images using automatically generated
sequences, which are then indexed so that the generated test images
can be compared to reference images, so as to select one or more
alternate nozzle correction patterns or nozzle control
sequences.
[0036] Head analysis system 130 receives non-functional ink jet
nozzle identification data and selects nozzle correction pattern
data and nozzle control sequence data for the ink cartridge. In one
exemplary embodiment, an ink cartridge can include one or more
non-functional ink jet nozzles, such that the ink cartridge may
otherwise need to be discarded if corrective action is not taken to
compensate for the non-functional ink jet nozzles. Head analysis
system 130 receives non-functional nozzle identification data,
nozzle correction pattern data, and nozzle control sequence data,
and determines whether a suitable set of nozzle correction pattern
data and nozzle control sequence data exists to allow the ink
cartridge to be used. In one exemplary embodiment, head analysis
system 130 can include a table of allowable configurations for
non-functional ink jet nozzles, and can determine based on the
non-functional nozzle identification data received for an ink
cartridge whether allowable nozzle correction pattern data and
nozzle control sequence data exists for the set of non-functional
ink jet nozzles. In this manner, head analysis system 130 can
increase the production yield of a production run of ink
cartridges, by identifying ink cartridges with non-functional ink
jet nozzles that can otherwise be used in conjunction with such
nozzle correction pattern data and nozzle control sequence
data.
[0037] Head analysis system 130 can interface with color indexing
system 108 or other suitable systems to store the non-functional
nozzle identification data for an ink cartridge, such as by storing
the nozzle correction pattern data and nozzle control sequence data
on a data storage device of ink characterization system 102, on a
data storage device of the ink cartridge, by transmitting the data
to an ink correction system 104, by transmitting the non-functional
nozzle identification data to ink correction system 104, where ink
correction system 104 can calculate or retrieve the nozzle
correction pattern data and nozzle control sequence data, or using
other suitable processes or configurations.
[0038] In operation, system 100 can be used as part of a
manufacturing process to generate and distribute color
characterization data for ink cartridges, to provide nozzle
correction patterns or nozzle control sequences that compensate for
non-functional ink jet nozzles, or for other suitable purposes. Ink
characterization system 102 can be used to develop reference ink
cartridge color characterization data and specimen ink cartridge
color characterization data for specific cartridges.
[0039] Camera calibration system 106 can be used to control the
quality and repeatability of image data measurements made by
different cameras, so as to perform high speed color density
measurement and to avoid the need for expensive special-function
devices, such as calorimeters and spectrophotometers.
[0040] Color indexing system 108 receives color characterization
data for specimen ink cartridges and reference ink cartridges and
provides the data on demand, with each cartridge, or in other
suitable manners.
[0041] Index interface system 110 allows the user to obtain the
cartridge correction data, either by querying color indexing system
108 over communications medium 114, by retrieving the reference ink
cartridge data and specimen ink cartridge data from a data storage
device of the cartridge, or in other suitable manners.
[0042] Cartridge correction system 112 uses the reference ink
cartridge data and specimen ink cartridge data to determine
correction factors for controlling printing. For example, the
reference ink cartridge may be used to generate color density
levels that are used to comply with standard organizations so as to
insure consistent and uniform color of images on printed media,
projectors, video screens, or in other suitable applications.
Nevertheless, individual ink cartridges may produce
non-standardized color density due to ink quality variations,
nozzle parameter or functionality variations, or other factors.
[0043] System 100 allows ink cartridges to be characterized on a
factory floor or in other suitable locations, such as a centralized
testing facility, so that the characterization data can be provided
to the users for correction of color so as to ensure that the color
of an original image is accurately reproduced. In this manner, the
color characterization data for each cartridge can be used to
determine whether a correction factor is required, and to generate
the correction factor.
[0044] FIG. 2 is a diagram of a system 200 for providing camera
calibration in accordance with an exemplary embodiment of the
present invention. System 200 includes camera calibration system
106 and filter standard system 202, color density measurement
system 204, camera filter correction system 206, and camera data
system 208, each of which can be implemented in hardware, software,
or a suitable combination of hardware and software, and which can
be one or more software systems operating on a general purpose
processing platform.
[0045] Filter standard system 202 stores and provides standard
density data in accordance with one or more standards. In one
exemplary embodiment, filter standards for density measurement can
be provided for red-green-blue filters in various bandwidth and
shapes, such as Status T, Status E, DIN, etc. In one exemplary
embodiment, if filter standard system 202 is being implemented in
North America, the Status T filter standard would be used, as it
has been adopted as the densitometry standard for graphics arts in
North America. The Status T filter standard employs three wide-band
filters. The measurements are a triplet of red density, green
density, and blue density. The red density is most sensitive to the
cyan patches, green density for magenta patches, and blue density
for yellow patches. As a result, only one reading needs to be
stored for each of the color patches, since the characterization
chart contains only cyan, magenta, and yellow patches in various
dot activations. Filter standard system 202 thus provides
standardized data for a sample, such as an expected density value
for the sample.
[0046] Color density measurement system 204 performs color density
measurements of samples. In one exemplary embodiment, color density
measurement system 204 is used to provide a camera that is being
calibrated with one or more sample colors for measurement, where
each sample has a known color density measured in accordance with
one or more color standards. The known color density can be stored
on the sample, can be stored in filter standard system 202 and
associated with an identifier for the sample, or can be provided in
other suitable manners. Color density measurement system 204 then
receives the data generated by the camera and generates a color
density measurement. This color density measurement can then be
compared with filter standard system 202 data or other suitable
data.
[0047] Camera filter correction system 206 is used to generate
correction factors for a camera so that it can perform repeatable
measurements with other calibrated cameras. In one exemplary
embodiment, camera filter correction system 206 receives filter
standard data from filter standard system 202 and color density
measurement data from color density measurement system 204 and
determines whether there is a difference. For example, if a cyan
sample is being measured and a filter standard system 202 provides
the value of 255 for the pixel brightness, and a camera being
calibrating provides 248, then the difference can be due to a
difference in the spectral power distribution of the light
illumination source or the spectral response of the camera filter
elements. Camera filter correction system 206 generates a
correction factor so that the colors measured by the camera as
corrected by the correction factor matched the colors indicated by
filter standard system 202.
[0048] Camera data system 208 stores camera correction data from
camera filter correction system 206 or other suitable sources and
provides the data as needed to allow the calibrated cameras to be
used in suitable processes, such as manufacturing processes. In one
exemplary embodiment, camera data system 208 can be accessed over a
communications medium when a camera is being installed for use,
such as by receiving the camera identification number and providing
the camera calibration data. Likewise, camera data system 208 can
be used to store the calibration data with the camera, on a
suitable storage media or in other suitable manners. For example,
camera data system 208 can prompt an operator to enter a camera
identification number before allowing a manufacturing process to
begin, and can then confirm whether the camera has been calibrated
within a specified calibration period or after a predetermined
event, such as on a daily basis, in response to a change in
lighting, or at other suitable times. If so, then the calibration
factors can be supplied, otherwise an error message can be
generated requesting the user to perform camera calibration or
other suitable processes.
[0049] In operation, system 200 is used to calibrate a digital
video camera for use in color characterization. System 200
compensates for variations in the spectral power distribution of
the illumination source, the spectral responsivity of the camera
pixels and filters, or other variations that may create differences
in colors measured with a camera as compared to the color as
measured in accordance with standards and special-function
equipment such as calorimeters or spectrophotometers. System 200
thus allows manufacturing processes such as calibration of test
equipment, periodic replacement of test equipment, periodic
checking of test equipment, or other suitable processes to be
performed. Likewise, system 200 allows high speed digital imaging
cameras to be used in place of colorimeters or other equipment that
provides accurate measurement capabilities but which is more
expensive or which takes longer to operate and thus would not be
feasible in the manufacturing environment.
[0050] FIG. 3 is diagram of a system 300 for performing color
indexing in accordance with an exemplary embodiment of the present
invention. System 300 includes color indexing system 108 and
uniformity correction system 302, edge detection system 304, patch
size system 306, image rotation system 308, density calculation
system 310, noise reduction system 312, cartridge data system 314,
and reference ink cartridge system 316, each of which can be
implemented in hardware, software, or a suitable combination of
hardware and software, and which can be one or more software
systems operating on a general purpose processing platform.
[0051] Uniformity correction system 302 can correct non-uniformity
due to lighting of a color sample. In one exemplary embodiment, the
following equations can be applied to perform this correction:
G.sub.d(x,y,) dark field with lens capped
G.sub.w(x,y,) white field with the blank paper; and
P.sub.p(x,y)=[P(x,y)-G.sub.d(x,y,)]/[G.sub.w(x,y,)-G.sub.d(x,y,)]
[0052] where
P.sub.p(x,y) is the corrected image pixel for a given image pixel
P(x,y).
[0053] This correction factor thus compensates for changes in
brightness so that consistent measurements can be taken regardless
of the illumination of the sample.
[0054] Edge detection system 304 locates color calibration patches
such that color values can be calculated for each patch. In one
exemplary embodiment, edge detection system 304 locates the upper,
lower, left, and right bounds and then the pixel locations of the
four corners located in the upper bound and the lower bound. In
this exemplary embodiment, the image is scanned from the top down
on the center pixel column until a vertical grade is detected
(i.e., a substantial difference between two adjacent vertical
pixels). When the test color patch includes a row of red, then
green, and then blue pixels, the upper bound can be located when
there is a red vertical gradient is detected (red is the
complimentary channel of cyan). Similarly, the lower bound can be
found with the scan line from the bottom up when a blue vertical
gradient is detected (blue is the complimentary channel of yellow).
Several columns of pixels can be averaged so as to obtain a better
signal/noise ratio.
[0055] Edge detection system 304 can also be used to locate the
left and right bounds by scanning the image from left to right on
the center row to detect a horizontal gradient (i.e., a substantial
difference between two neighboring horizontal pixels). When the
test color patch includes a first patch having 100% dot activation
for indexing, and a last patch having 100% dot activation for color
characterization, the left bound can be found when a green
horizontal gradient is detected (green is the complimentary color
channel of magenta). A similar process can be used scanning from
right to left to detect the right bound. Several rows of pixels can
also be averaged so as to obtain a better signal/noise ratio.
[0056] Edge detection system 304 can also be used to locate the
corner pixels by testing the pixel values around the upper left
corner in the neighborhood determined by the intersection of the
upper bound and left bound to determine the coordinates of the
exact upper left corner pixel, and by repeating this process to
determine the coordinates of the pixels for the rest of the
corners.
[0057] Patch size system 306 calculates the patch size based on
predetermined patch characteristics, such as patch numbers, patch
sizes, and other patch criteria. For example, if twenty-one patches
are used ranging from zero to one hundred percent in five percent
increments, then the patch size system 306 can generate patch
coordinate data based on this predetermined patch criteria data.
Likewise, patch size system 306 can prompt the user to enter the
number of patches, can prompt the user to confirm the identify
patches and data, or can perform other suitable processes.
[0058] Image rotation system 308 determines whether image data
defining a color test patch needs to be rotated. For example, since
the amount of angular correction is small in most cases, the amount
of rotation can be approximated by the number of rows of pixels
between the corner coordinates for the four patch corner
coordinates. For example, if the top two corners have coordinates
of (X1,0) and (X2, -3), an angle of rotation .THETA. can be
approximated as .DELTA.Y/.DELTA.X, or -3/(X2-X1). Image rotation
can then be performed by the following manner. For each row, detect
the left bound as the origin, locate each pixel on the row to be
rotated.
X'=X cos .THETA.+Y sin .THETA.
Y'=-X sin .THETA.+Y cos .THETA.
[0059] The second terms are zero if the first pixel of each row is
the origin. Each rotated image point P(X', Y') can thus be
determined. Density calculation system 310 calculates the pixel
image data density of each patch. In one exemplary embodiment, the
following equation can be used:
D=log 10(P.sub.AVG/255)
[0060] where P.sub.AVG is the average color pixel value of a given
patch. Likewise, other suitable statistical data can also or
alternatively be calculated.
[0061] Noise reduction system 312 can be used to improve the signal
to noise ratio, such as by averaging the pixels of each patch.
Furthermore, as the image data values of the pixels along the
border of each patch can be degraded due to various factors, such
as the modular transfer function of the optical system of the
camera, the resolution of the printer, and the number of the
elements of the CCD imager, a number of bordering pixels can also
be excluded in the calculation of the patch image data density
values. Noise reduction system 312 can also check the linearity of
the camera against Commission Internationale de l'Eclairage
(International Commission on Illumination or CIE) XYZ tristimulus
values with the twenty-four step gray wedge on the R1200008 Kodak
Q60 Target (SRGB) target. The camera's RGB readings can be
linearized with the following equation
R'=R*Y/Y.sub.n
[0062] where
[0063] R' is the linearized red value
[0064] R is the original red values
[0065] Y is the corresponding tristimulus Y value, and
[0066] Y.sub.n is the Y value of the blank media
[0067] Similar equations can be used to linearize green and blue
values.
[0068] Cartridge data system 314 receives specimen ink cartridge
color density characterization data, specimen ink cartridge
identification data, specimen ink cartridge type data, and other
suitable data and stores the data in a relational database. In
addition, cartridge data system 314 provides the data upon demand,
such as when specimen ink cartridge identification data is provided
by a user when the specimen ink cartridge is being installed. Other
suitable processes can also or alternatively be used, such as
storing the specimen ink cartridge data in a data storage device of
the specimen ink cartridge.
[0069] Reference ink cartridge system 316 receives reference ink
cartridge color density characterization data, reference ink
cartridge type data, and other suitable data and stores the data in
a relational database. In addition, reference ink cartridge system
316 provides the data upon demand, such as when specimen ink
cartridge identification data is provided by a user when the
specimen ink cartridge is being installed, and specimen ink
cartridge type data is used to correlate the specimen ink cartridge
to a reference ink cartridge. Other suitable processes can also or
alternatively be used, such as storing the reference ink cartridge
data in a data storage device of the specimen ink cartridge.
[0070] In operation, system 300 allows color density data to be
generated for use with reference ink cartridge color
characterization data, specimen ink cartridge color patch, or other
suitable data, and allows the specimen ink cartridge data and the
reference ink cartridge data to be provided for use in controlling
the specimen ink cartridge color. System 300 thus facilitates the
generation of reference ink cartridge color characterization data
and specimen ink cartridge color characterization data for color
characterization and control.
[0071] FIG. 4 is a diagram of a system 400 for index interfacing in
accordance with an exemplary embodiment of the present invention.
System 400 includes index interface system 110 and cartridge
detection system 402, cartridge identification system 404,
cartridge data interface system 406, and reference cartridge system
408, each of which can be implemented in hardware, software, or a
suitable combination of hardware and software, and which can be one
or more software systems operating on a general purpose processing
platform.
[0072] Cartridge detection system 402 generates cartridge
replacement data. In one exemplary embodiment, cartridge detection
system 402 can detect whether an ink cartridge is present in a
carriage, and can generate query data or other suitable data if it
determines that the state of the carriage has gone from occupied to
unoccupied or has otherwise changed in a manner that indicates that
the cartridge is being replaced. In one exemplary embodiment,
cartridge detection system 402 can generate a query asking the user
to indicate whether a new cartridge has been provided. Likewise,
cartridge detection system 402 can automatically detect the
cartridge, such as by reading a cartridge identifier from a data
memory device of the cartridge or other suitable devices.
[0073] Cartridge identification system 404 works in conjunction
with cartridge detection system 402 to obtain cartridge
identification data. For example, if cartridge detection system 402
requests the user to indicate whether or not the cartridge has been
exchanged, then cartridge identification system 404 can
subsequently prompt the user to provide the cartridge identifier if
the user indicates that the cartridge has been changed. Likewise,
cartridge identification system 404 can read cartridge data using
optical imaging or by other suitable processes.
[0074] Cartridge data interface system 406 receives cartridge data
for processing. In one exemplary embodiment, cartridge data
interface system 406 can initiate an Internet connection, using
existing Internet connection, initiate a telephone connection, or
use other suitable processes to access a website, IRC site, or
other suitable locations at which cartridge characterization data
is stored for a cartridge. The cartridge data can include color
density data, color characterization data, reference cartridge
data, non-functional nozzle identification data, nozzle correction
pattern data, nozzle control sequence data, or other suitable
data.
[0075] Reference cartridge system 408 stores color characterization
data for a reference ink cartridge. In one exemplary embodiment,
reference cartridge system 408 can receive reference ink cartridge
data from a manufacturer or other suitable sources, can allow a
user to create a reference ink cartridge by using one or more
calibrated cartridges, or can perform other suitable functions.
[0076] In operation, system 400 allows a remote processor to access
specimen ink cartridge data, reference ink cartridge data, and
other suitable data for use in generating color characterization
and control data. System 400 allows such processes to be performed
automatically, with user intervention, or in other suitable
manners.
[0077] FIG. 5 is a diagram of a system 500 for controlling a color
cartridge in accordance with an exemplary embodiment of the present
invention. System 500 includes cartridge correction system 112 and
compensation factor system 502, correction factor calculation
system 504, ink control system 506, and ink jet compensation system
508, each of which can be implemented in hardware, software, or a
suitable combination of hardware and software, and which can be one
or more software systems operating on a general purpose processing
platform.
[0078] Compensation factor system 502 provides a compensation
factor for use in determining a correction factor. In one exemplary
embodiment, when a correction factor is calculated, an empirical
compensation factor can also be applied where it has been
determined that using the calculated compensation factor either
over compensates or under compensates. For example, if a reference
ink cartridge color density for a pre-determined dot activation is
100% and the specimen ink cartridge color density for that dot
activation is 90%, then the specimen ink cartridge dot activation
would need to be increased so as to provide more ink to generate
the 1.0 color density. In this example, it might be determined that
the specimen ink cartridge generates the 1.0 color density with a
dot activation of 90. However, when 90 percent is used for the
specimen ink cartridge, the color density realized in operation
might be 0.9. Compensation factor system 502 can be used to adjust
the dot activation from 90 percent to a value higher than 90
percent, such as one that is empirically determined.
[0079] Correction factor calculation system 504 generates a
correction factor for use in correcting and controlling color. In
one exemplary embodiment, correction factor calculation system 504
receives a specimen ink cartridge color density function and a
reference ink cartridge color density function and maps the
specimen ink cartridge to the reference ink cartridge. For example,
if the reference ink cartridge color density for a dot activation
is X and the specimen color density is Y, then a correction factor
of X-Y is required. However, if the specimen ink cartridge dot
activation is corrected to provide the full X-Y correction, then it
may be determined that the correction overcompensates the amount of
color, such that a correction factor of less than X-Y is desirable,
as described above. Thus, correction factor calculation system 504
can calculate a theoretical correction factor, an actual correction
factor using compensation factor system 502 or other suitable
correction factors.
[0080] Ink control system 506 receives the correction factor
generated by correction factor calculation system 504 and generates
printing control data so as to generate accurate colors. In one
exemplary embodiment, ink control system 506 can receive color
density curve coefficients generated by curve fitting the specimen
ink cartridge data on to the reference ink cartridge data, can
generate a look-up table with 256 or 4096 data points, or can use
other suitable processes to generate printing control data. For
example, for a color density of D1, the reference ink cartridge
data may indicate that a dot activation of N1 needs to be
generated, but the mapped specimen ink cartridge data may indicate
that a dot activation of N2 needs to be provided. Furthermore,
after applying a correction factor, it may be determined that a dot
activation of N3 is actually required. Ink control system 506
receives the values of N1 and maps them to values of N2 or N3, as
appropriate.
[0081] In another exemplary embodiment, ink control system 506 can
receive nozzle correction pattern data or nozzle control sequence
data and can modify printer control data that is generated for an
ink cartridge with a fully-functional set of ink jet nozzles, so as
to generate printer control data for an ink jet cartridge with
non-functional ink jet nozzles. In this exemplary embodiment, ink
control system 506 can interface with ink jet compensation system
508, data storage devices, or other suitable systems or devices to
receive nozzle correction pattern data and nozzle control sequence
data for an ink cartridge having one or more non-functional ink jet
nozzles. In another exemplary embodiment, ink control system 506
can receive one or more characteristic equations that define
alternate nozzle correction patterns and alternate nozzle control
sequences as a function of non-functional ink jet nozzle
identification data, and can generate printer control data based
upon the failed non-functional ink jet nozzle identification data
and such characteristic equations.
[0082] Ink jet compensation system 508 receives ink cartridge
identification data and retrieves non-functional ink jet nozzle
data. In one exemplary embodiment, ink jet compensation system 508
can interface with index interface system 110 or other suitable
systems to retrieve non-functional ink jet nozzle data from a
remote location. Likewise, ink jet compensation system 508 can
interface with a data storage device of the ink cartridge, which
can include non-functional ink jet nozzle identification data. In
another exemplary embodiment, ink jet compensation system 508 can
query one or more devices on an ink cartridge that provide
non-functional ink jet nozzle data and can use the non-functional
ink jet nozzle identification data to obtain nozzle correction
pattern data and nozzle control sequence data. In this exemplary
embodiment, ink jet compensation system 508 can interface through a
communications medium with a remote data storage location, can
generate files of correction pattern data and nozzle control
sequence data from characteristic equations, can retrieve nozzle
correction pattern data and nozzle control sequence data from a
local database, can retrieve the nozzle correction pattern data and
nozzle control sequence data instead of determining the
non-functional ink jet nozzles, or can perform other suitable
functions.
[0083] In operation, system 500 performs color correction for
specimen ink cartridges. System 500 receives specimen ink cartridge
data, reference ink cartridge data, compensation factor data, or
other suitable data, and determines the percentage of dots to fire
for a desired color density. System 500 thus can be used to insure
that the colors generated are representative of colors that would
be generated by a standardized process.
[0084] FIG. 6 is a flowchart of a method 600 for providing
compensation for non-functional ink cartridge ink jet nozzles in
accordance with an exemplary embodiment of the present invention.
Method 600 allows ink jet cartridges with non-functional ink jet
nozzles to be used in a manner that does not noticeably impair the
image data generated using the ink cartridge.
[0085] Method 600 begins at 602 where a camera is calibrated. In
one exemplary embodiment, camera calibration can be performed using
camera calibration procedures specified by one or more industry
standards, camera calibration procedures used to.sub.3 allow
non-specialized cameras to measure color density, or other suitable
camera calibration procedures. The method then proceeds to 604.
[0086] At 604 a test pattern is printed. In one exemplary
embodiment, the test pattern can be developed to identify one or
more non-functional ink jet nozzles. This test pattern can include
one or more patches in which varying numbers and configurations of
ink jet nozzles are activated, so as to allow the image data to be
analyzed to identify non-functional ink jet nozzles. The method
then proceeds to 606.
[0087] At 606, the ink jet nozzle operability data is determined by
analyzing the image data. In one exemplary embodiment, the image
data generated can be analyzed using a suitable procedure, such as
comparison to a reference image, histographic analysis of the image
data after processing with one or more templates, or other suitable
data. For example, the image data can include an N.times.M pixel
array that has been indexed to a reference point, and a template
can be applied to block image data for predetermined pixel
locations, where such pixel locations correspond to inactive or
non-activated ink jet nozzles. In this exemplary embodiment, a
histogram of image data that has been processed using the template
should indicate a high frequency of pixels at locations having
brightness values indicative of functional ink jet nozzles. If
brightness values indicative of non-functional ink jet values are
detected, additional test patterns can be printed. Likewise, other
suitable processes can be used. The method then proceeds to
608.
[0088] At 608, ink jet nozzle data is stored. In one exemplary
embodiment, the ink jet nozzle data can include one or more arrays
of non-functional ink jet nozzles, nozzle correction pattern data
determined from a local database based on the non-functional ink
jet nozzle data, nozzle control sequence data from a local
database, or other suitable data. The method then proceeds to
610.
[0089] At 610, the ink cartridge is shipped. In one exemplary
embodiment, cartridge identification data can be stored in addition
with non-functional ink jet nozzle identification data, nozzle
correction pattern data, nozzle control sequence data, or other
suitable data, such as in a data storage device of the ink
cartridge, in a database accessible over a communications medium,
or in other suitable configurations or using other suitable
processes. The method then proceeds to 612.
[0090] At 612 the cartridge is installed at an end user location.
In one exemplary embodiment, the identity of the end user is
unknown until the cartridge is installed. Installation of the
cartridge can also activate devices that are used to read data
stored on a data storage device of the cartridge, identification
data printed on the cartridge, or other suitable processes. The
method then proceeds to 614.
[0091] At 614 cartridge identification data is determined. In one
exemplary embodiment, data read from a data storage device or from
markings on the cartridge is analyzed to determine the cartridge
identification data. In another exemplary embodiment, the user can
be queried to enter cartridge identification data. Other suitable
processes can also or alternatively be used. The method then
proceeds to 616.
[0092] At 616 nozzle operability data is received. In one exemplary
embodiment, the nozzle operability data can be a set of
non-functional ink jet nozzles, non-functional ink jet nozzle
identification data, or other suitable nozzle operability data. The
method then proceeds to 618.
[0093] At 618 nozzle correction pattern data and nozzle control
sequence data is generated. In one exemplary embodiment, the
non-functional ink jet nozzle data can be used to access a table of
stored values at a remote location or locally, can be used as input
to a characteristic equation, or other suitable processes can be
used to generate the nozzle correction pattern data and nozzle
control sequence data. Likewise, the nozzle correction pattern data
and nozzle control sequence data can be provided directly without
the intermediate step of providing the non-functional ink jet
nozzle data. The method then proceeds to 620.
[0094] At 620 the nozzle correction pattern data and nozzle control
sequence data is applied to printer control data. In one exemplary
embodiment, printer control data can be generated based on a fully
functional set of ink jet nozzles, and the printer control data can
then be modified to compensate for the non-functional ink jet
nozzles. Likewise, the printer control data can be generated using
equations or relationships that have been modified to compensate
for the one or more non-functional ink jet nozzles, or other
suitable processes can be used so as to allow ink cartridges with
non-functional ink jets to be used to print image data without
detectable changes in image quality.
[0095] In operation, method 600 allows non-functional ink jet
nozzles to be identified and compensated for, so as to allow ink
cartridges that would otherwise include an unacceptable level of
non-functional ink jet nozzles to be used without any noticeable
degradation in image quality. Method 600 characterizes the number
of non-functional ink jet nozzles of an ink cartridge, and then
determines nozzle correction pattern data and nozzle control
sequence data that can be used to control the ink cartridge so as
to generate image data that is not noticeably different to an
observer from image data generated using an ink cartridge with a
full set of functional ink jet nozzles.
[0096] FIG. 7 is a flowchart of a method 700 for generating nozzle
correction pattern data and nozzle control sequence data in
accordance with an exemplary embodiment of the present invention.
Method 700 begins at 702 where nozzle correction patterns are
mapped. In one exemplary embodiment, a plurality of nozzle
correction patterns can be generated for an ink cartridge, such as
nozzle correction patterns where one or more ink jet nozzles
adjacent to one or more non-functional ink jet nozzle are activated
to compensate for the non-functional ink jet nozzles, patterns
where one or more functional ink jet nozzles are fired at a
location to compensate for one or more non-functional ink jet
nozzles, or other suitable patterns. In one exemplary embodiment,
an N.times.M array of ink jet nozzles can be used, where the ink
jet nozzle at coordinate location (1,1) has failed. Nozzle
correction patterns can be generated where the ink jet nozzle at
coordinates (1,2), (2,2) and (2,1) are generated, so that the image
data can be compared to a reference image, so that color density
data can be generated, or so that other suitable processes can be
performed. In this exemplary embodiment, the printer head can be
activated at predetermined levels of percent of ink jet nozzles
activated, such as 10%, 20%, and so forth up to 100%. The nozzle
correction patterns can be generated for each level using the
replacement nozzles, or data can be generated to indicate that the
replacement nozzle for that configuration would normally be
activated. For example, where ink jet nozzle (1,1) has failed, and
100% of nozzles are to be activated, it could be determined that
each of the ink jet nozzles at coordinate locations (1,2), (2,2),
and (2,1) are required for 100% activation, such that none of these
adjacent ink jet nozzles are available to replace the
non-functional ink jet nozzle. In this exemplary embodiment, data
can be generated indicating that there are no available replacement
nozzles for a nozzle correction pattern. Likewise, other suitable
ink jet nozzle failure conditions, replacement ink jet nozzle
conditions, and replacement nozzle data can be generated. The
method then proceeds to 704.
[0097] At 704 nozzle control sequences are mapped. In one exemplary
embodiment, an ink jet cartridge can be used to generate image data
in a series of passes, where a first set of ink jet nozzles are
activated when the ink cartridge is moved from left to right and a
second set of ink jet nozzles is activated when the ink cartridge
is moved from right to left. Likewise, as the ink cartridge
advances line by line, there may be some overlap, such that a given
point may be exposed to two or more rows of ink jet nozzles. For
example, with an M.times.N array of ink jet nozzles, a point on a
page may be capable of being sprayed by ink from an ink jet nozzle
at coordinate (1,1) during a first pass of the ink cartridge from
left to right, and at the same coordinate during the return pass of
the ink cartridge from right to left. The ink cartridge may then
subsequently advance one-half of a line, such that the ink
cartridge now can spray ink at the location covered by the failed
nozzle using an ink jet nozzle having coordinates (1, X), where
M<X<N. In this manner, a nozzle control sequence can be
determined that allows a point to be sprayed with ink at a
different point in the printing process, such as at a first forward
or reverse pattern, a second forward or reverse pattern, or other
available forward or reverse patterns. Thus, if a nozzle correction
pattern is not available that would allow that location to be
sprayed with ink, a nozzle control sequence might be able to allow
that location to be sprayed. After all nozzle control sequences
have been generated the method then proceeds to 706.
[0098] At 706, interchangeability of nozzle correction patterns and
nozzle control sequences is determined. In one exemplary
embodiment, the set of nozzle correction pattern test data and
nozzle control sequence test data can be compared with reference
images, where difference image data is generated and analyzed to
determine whether the difference between the reference image and
the test image data exceeds predetermined threshold levels. For
example, histogram analysis, image data grouping analysis, or other
suitable processes can be used to determine whether the differences
between the generated test image and the reference image would be
able to be noticeable to an observer. The method then proceeds to
708.
[0099] At 708 nozzle correction patterns and nozzle control
sequences are stored that can be used to replace non-functional ink
jet nozzles without creating a noticeable difference between image
data generated using a full set of functional ink jet nozzles. In
one exemplary embodiment, the nozzle correction pattern data and
the nozzle control sequence data is stored in a database
cross-referenced with non-functional ink jet nozzle data, such that
for a given set of non-functional ink jet nozzle data, a
corresponding nozzle correction pattern data set or nozzle control
sequence data set can be retrieved. Likewise, if a nozzle
correction pattern data sequence is available and a nozzle control
sequence data pattern set is available, a preference for one or the
other could be used, such as where implementation of a nozzle
correction pattern is easier than implementation of a nozzle
control sequence. Likewise, other suitable processes can be
used.
[0100] In operation, method 700 allows one or more sets of nozzle
correction pattern data and nozzle control sequence data to be
generated to compensate for non-functional ink jet nozzles. Method
700 thus allows the production yield for ink jet cartridges to be
increased, by allowing ink jet cartridges that would otherwise be
considered unusable to be used, such as by compensating for
non-functional ink jet nozzles through activation of other
equivalent ink jet nozzles or by activation of ink jet nozzles in
previous or subsequent printer head passes, such as where such
other nozzles can print at the location where the non-functional
ink jet nozzles would have printed.
[0101] FIG. 8 is a flowchart of a method 800 for determining
whether a nozzle correction pattern or nozzle control sequence for
a non-functioning ink jet nozzle is acceptable in accordance with
an exemplary embodiment of the present invention. Method 800 begins
at 802 where a correction pattern or sequence is used to print a
test image. In one exemplary embodiment, a series of test patches
can be generated using different nozzle correction patterns and
nozzle control sequences, and a set of acceptable nozzle correction
patterns and nozzle control sequences can be identified. The method
then proceeds to 804.
[0102] At 804 the test images are compared to a reference pattern,
such as one generated using an ink cartridge with fully functional
ink jet nozzles. Likewise, the nozzle correction patterns and
nozzle control sequences generated at 802 can include varying
degrees of ink jet nozzle activation, such as in 10% increments
(e.g., from 0% of nozzles activated to 100% of nozzles activated in
10% nozzle activation steps), for predetermined patterns in which
the non-functioning ink jet nozzle would be activated, or in other
suitable manners.
[0103] At 806 it is determined whether the density of each test
image is acceptable. For example, the color density of a test image
can be determined using a calibrated image data measurement device,
and then can be compared to the color density measured for the
reference image. If it is determined that the color density is not
acceptable the method proceeds to 810. Otherwise the method
proceeds to 808.
[0104] At 808 it is determined whether the image map is acceptable.
In one exemplary embodiment, the test image may generate image data
that is noticeably different from the reference image data. For
example, benchmark data sets or templates can be used based on
differences that were observable to a population of observers, and
these benchmarks can be applied to the test image data to determine
whether the differences between the reference image and the test
image would be noticeable to observers. Likewise, a population of
observers can also be used to make subjective determinations, or
other suitable procedures can be used. If it is determined that the
image map is not acceptable the method proceeds to 810 and the
nozzle correction pattern or nozzle control sequence that was used
to generate that test image data is rejected. Otherwise, the method
proceeds to 812 and the nozzle correction pattern or nozzle control
sequence that was used to generate that test image data is stored
for use. The method then proceeds to 814.
[0105] At 814 it is determined whether additional nozzle correction
patterns or nozzle control sequences need to be analyzed. For
example, a set of nozzle correction patterns or nozzle control
sequences can be generated for each ink jet nozzle in the ink jet
nozzle array, for combinations of two ink jet nozzles in the ink
jet nozzle array, and so forth until all acceptable nozzle failure
combinations have been identified. For example, in an N.times.M ink
jet nozzle array, it can be determined that a set of X failed
nozzles is acceptable if certain degrees of separation exists
between each of the X nozzles, such as one row of separation, one
column of separation, one row and one column of separation, or
other suitable metrics. Likewise, it can also be determined that
two or more adjacent nozzles out of the set of X non-functioning
ink jet nozzles is acceptable, as long as there are predetermined
degrees of separation between such adjacent non-functioning ink jet
nozzles and all other non-functioning ink jet nozzles. Likewise,
other suitable parametric equations can be determined, where the
parametric equation can be used to determine nozzle correction
patterns or nozzle control sequences based on an input set of
non-functioning ink jet nozzles. Once it is determined that there
are no more nozzle correction patterns or nozzle control sequences
for which acceptable alternate ink jet nozzles exist, the method
proceeds to 816 where the nozzle correction patterns or nozzle
control sequences are installed in a printer, such as when the
printer driver is activated, by transmitting them over a
communications medium when the ink cartridge is installed in the
printer, or in other suitable manners. Otherwise, the method
returns to 802.
[0106] In operation, method 800 allows nozzle correction patterns
and nozzle control sequences to be tested to determine whether
images generated using those nozzle correction patterns or nozzle
control sequences are suitable replacement images for image data
generated using fully functional nozzles. Method 800 allows a set
of non-functional ink jet nozzles to be tested to determine whether
other functional ink jet nozzles can be used to compensate for the
non-functional nozzles.
[0107] FIG. 9 is a diagram 900 of non-functional ink jet nozzle
patterns in accordance with an exemplary embodiment of the present
invention. The non-functioning ink jet nozzle patterns include
[3.times.3] array 902, [3.times.4] array 904, [4.times.4] array
906, and [3.times.5] array 908, in which the non-functioning nozzle
location is shown as a darkened square and the functioning nozzle
locations are shown as circles with associated letters. For ink jet
nozzle array 902, any of functioning ink jet nozzles A through H
can be used in place of the non-functioning nozzle. Thus, if a
nozzle correction pattern can be used for every print location, a
nozzle control sequence might not be necessary to compensate for
the non-functioning ink jet nozzle shown in nozzle array 902. For
example, the ink jet nozzles in rows [A, B, C] and [F, G, H] can be
used to print when the ink jet head is traversing from left to
right, whereas the row containing the non-functioning ink jet
nozzle and functioning ink jet nozzles D and E could be used to
print when the ink jet head is traversing from right to left. In
this exemplary embodiment, using ink jet B or G in place of the
failed ink jet nozzle might be acceptable and not cause damage to
ink jet nozzles B and G if they are alternated. Likewise, if ink
jet nozzles A, C, F and H are used in one direction and D, B, E and
G are used in a different direction, it may be possible to
alternate the use of ink jet nozzles to compensate for the
non-functioning ink jet nozzle. Whether or not such alternate
nozzles could be used can be determined empirically, based on an
analysis of image data generated for test images as compared to
reference images, or in other suitable manners.
[0108] Likewise, for ink jet nozzle array 904, the combination of
two adjacent failed non-functioning ink jet nozzles can require a
combination of ink jet nozzles to be used such as nozzles B and H,
G and C, D and J, F and I, K and A, or other suitable combinations.
Depending on the availability of such other ink jet nozzles for
every possible combination of ink jet nozzle activation, an ink
cartridge that includes ink jet nozzle array 904 may not have a
nozzle correction pattern that can be used. Nevertheless, it is
likewise possible that two functioning ink jet nozzles could be
placed over the location where the two failed ink jet nozzles
should be activated, such that in a first pass, ink jet nozzle
array 904 is used and the two non-functioning nozzle points are
noted, and in the next subsequent pass, two functioning ink jet
nozzles that are placed over the location where the two
non-functioning ink jet nozzles from ink jet nozzle array 904 would
have been. The two functioning nozzles can then be activated, so as
to produce image data having the same visual qualities to an
observer. Thus, a nozzle control sequence can be used in addition
to or instead of a nozzle correction pattern to compensate for the
two non-functioning ink jet nozzles.
[0109] Ink jet nozzle array 906 shows four adjacent non-functioning
ink jet nozzles, such that the number of functioning ink jet
nozzles that are available to replace each non-functioning ink jet
nozzles has decreased. For example, in ink jet nozzle array 902,
the one non-functioning ink jet nozzle has eight available ink jet
nozzles to replace it. Likewise, in ink jet nozzle array 904, each
non-functioning ink jet nozzle has five functioning ink jet nozzles
that could be used to replace it. In ink jet nozzle array 906, each
non-functioning ink jet nozzle has only three adjacent functioning
ink jet nozzles that can be used to generate a nozzle correction
pattern. Thus, ink jet nozzle array 906 can be indicative of a
non-functioning ink jet nozzle arrangement that can be corrected
only by a nozzle control sequence, only by a nozzle correction
pattern, by either a nozzle control sequence or nozzle correction
pattern, or which cannot be corrected based on the location of
other non-functioning ink jet nozzles in the ink jet cartridge
printer head. Likewise, ink jet nozzle array 908 provides five
functioning ink jet nozzles to replace the two non-functioning ink
jet nozzles on either end of the three adjacent non-functioning ink
jet nozzles, and between two adjacent ink jet nozzles for the
middle non-functioning ink jet nozzle.
[0110] In operation, ink jet nozzle arrays 900 demonstrate ink jet
nozzle configurations in which non-functional ink jet nozzles can
be replaced with functional ink jet nozzles. Depending on the order
in which adjacent ink jet nozzles are fired, nozzle correction
patterns, nozzle control sequences, or a suitable combination of
both can be used to compensate for non-functional ink jet
nozzles.
[0111] FIG. 10 is a diagram of system 1000 for providing ink jet
head analysis in accordance with an exemplary embodiment of the
present invention. System 1000 includes head analysis system 130
and non-functional jet mapping system 1002, nozzle correction
pattern analysis system 1004, and nozzle control sequence analysis
system 1006, each of which can be implemented in hardware,
software, or a suitable combination of hardware and software, and
which can be one or more software systems operating on a general
purpose processing platform.
[0112] Non-functional jet mapping system 1002 analyzes image data
to determine the location of one or more non-functioning ink jet
nozzles. In one exemplary embodiment, non-functional jet mapping
system 1002 can use histogram analysis, templates, or other
suitable functions to compare test image data with reference image
data, or to otherwise analyze test image data to identify the
location of one or more non-functioning ink jet nozzles.
[0113] Nozzle correction pattern analysis system 1004 generates one
or more test images with correction patterns for non-functional ink
jet nozzles, and performs additional image data analysis on the one
or more test patterns to determine whether they can be used to
replace the image data generated by a fully functioning set of
nozzles. In one exemplary embodiment, nozzle correction pattern
analysis system 1004 can compare a set of nozzle correction
patterns to reference image data, and can determine whether the
nozzle correction patterns would be noticeably different to a user,
have different image color density, or other differences that
preclude the use of the nozzle correction pattern. Other suitable
processes can also or alternatively be used.
[0114] Nozzle control sequence analysis system 1006 determines
whether a nozzle control sequence exists for one or more
non-functioning ink jet nozzles. In one exemplary embodiment,
nozzle control sequence analysis system 1006 determines whether a
functioning nozzle arrangement can be used that passes over a
location where non-functioning nozzles are depositing ink, such
that one or more nozzle control sequences can be used to compensate
for the non-functioning ink jet nozzles. Likewise, nozzle control
sequence analysis system 1006 can determine whether such use of
functioning ink jet nozzles to replace non-functioning ink jet
nozzles can result in overuse of the ink jet nozzles, deterioration
of the ink jet nozzles before a design life, or whether other
suitable problems exist. Other suitable processes can also or
alternatively be used.
[0115] In operation, system 1000 allows ink jet cartridges to be
analyzed to identify ink jet nozzle parameters, such as patterns or
sequences, that will allow the non-functioning ink jet nozzles to
be compensated for by functioning ink jet nozzles, such as by
generation of nozzle correction patterns or nozzle control
sequences. System 1000 thus allows ink jet cartridges to be
characterized in a manufacturing facility to identify
non-functioning ink jet nozzles, and to determine nozzle correction
patterns and nozzle control sequences that can be used to allow
such ink jet cartridges with non-functioning ink jet nozzles to be
used by printers. Other suitable processes can also or
alternatively be used.
[0116] FIG. 11 is a diagram of a system 1100 for ink jet nozzle
compensation in accordance with an exemplary embodiment of the
present invention. System 1100 includes ink jet compensation system
508 and nozzle correction pattern system 1102, nozzle control
sequence system 1104, and printer control data modification system
1106, each of which can be implemented in hardware, software, or a
suitable combination of hardware and software, and which can be one
or more software systems operating on a general purpose processing
platform.
[0117] Nozzle correction pattern system 1102 receives
non-functioning ink jet nozzle identification data and selects
nozzle correction patterns that will allow image data to be
generated by an ink cartridge having such non-functioning ink jet
nozzles that simulates image data generated by a fully-functional
ink cartridge. In one exemplary embodiment, nozzle correction
pattern system 1102 includes a lookup table that returns nozzle
correction patterns for a given configuration of non-functional ink
jet nozzles. In another exemplary embodiment, nozzle correction
pattern system 1102 includes one or more characteristic equations
that can generate the nozzle correction pattern data in response to
non-functioning ink jet nozzle input data. Other suitable processes
can also or alternatively be used.
[0118] Nozzle control sequence system 1104 receives non-functioning
ink jet nozzle identification data and selects nozzle control
sequences that will allow image data to be generated by an ink
cartridge having such non-functioning ink jet nozzles that
simulates image data generated by a fully-functional ink cartridge.
In one exemplary embodiment, nozzle control sequence system 1104
includes a lookup table that returns nozzle control sequences for a
given configuration of non-functional ink jet nozzles. In another
exemplary embodiment, nozzle control sequence system 1104 includes
one or more characteristic equations that can generate the nozzle
control sequence data in response to non-functioning ink jet nozzle
input data. Other suitable processes can also or alternatively be
used.
[0119] Printer control data modification system 1106 processes
printer control data to generate printer control data that can be
used for an ink jet cartridge having one or more non-functioning
ink jet nozzles. In one exemplary embodiment, printer control data
modification system 1106 receives a set of image data and generates
printer control data for the ink jet cartridge having
non-functioning ink jet nozzles. In another exemplary embodiment,
printer control data modification system 1106 receives printer
control data generated for image data for an ink jet cartridge
having a fully functioning set of ink jet nozzles, and modifies the
printer control data to include printer control data for the
non-functioning ink jet nozzles. In this manner, printer control
data modification system 1106 can be used in conjunction with
existing systems, such as printer drivers, can be used to replace
such existing systems, or can be used in other suitable
configurations.
[0120] In operation, system 1100 allows an ink jet having one or
more non-functioning ink jet nozzles to be used in a printer, by
allowing the non-functioning ink jet nozzles to be compensated for.
System 1100 determines whether print patterns can be used to
simulate image data for a cartridge with non-functional ink jet
nozzles so that it appears to an observer to have been made by a
fully functional ink cartridge, or whether printer control data
sequences exist that can be used to print at locations where the
non-functioning ink jet nozzles would normally print. In this
manner, system 1100 allows increased ink cartridge manufacturing
yields to be realized by allowing ink cartridges that would
otherwise be discarded to be successfully used without any
degradation in image quality.
[0121] In view of the above detailed description of the present
invention and associated drawings, other modifications and
variations will now become apparent to those skilled in the art. It
should also be apparent that such other modifications and
variations may be effected without departing from the spirit and
scope of the present invention.
* * * * *