Patent US6236474B1 successfully refreshed from Google Patents.
US6236474B1
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Device independent color controller and method
Assignee: Xerox Corp
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Filing: 1998-05-22
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Granted: 2001-05-22
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Expires: 2018-05-22
Abstract
Abstract A method of correcting for error in an output color of a colored output image in a marking device intended to match a desired image includes the steps of detecting a current output color in the output image with a color sensing device, determining a difference between the current output color and a corresponding target color under standard conditions, and automatically setting a marking device input-output relationship for a next output color based on the difference between the current output color and the corresponding target color under standard conditions to minimize the difference between the next output color and the corresponding target color.
Inventors
- 👤 Lingappa K. Mestha
- 👤 Sohail A. Dianat
- 👤 Mark Alan Scheuer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 15:10
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/46; H04N1/56; H04N1/60; H04N1/603; H04N1/6033
Claims Analysis
Total Claims: 32
Claim 1
Independent Claim
87 words
A method of controlling an output color in a marking device to match a desired color of an input image, comprising: detecting the output color with a color sensing device; obtaining a target color in device independent space, comparing the detected output color with the target color; and automatically correcting, based on a difference between the output color and the target color, at least one tone reproduction curve of the marking device such that the output color of the marking device more accurately resembles the desired color.
Claim 2
Independent Claim
87 words
A method of controlling an output color in a marking device to match a desired color of an input image, comprising: detecting the output color with a color sensing device; obtaining a target color in device independent space, comparing the detected output color with the target color; and automatically correcting, based on a difference between the output color and the target color, at least one tone reproduction curve of the marking device such that the output color of the marking device more accurately resembles the desired color.
Claim 3
Independent Claim
109 words
A method of correcting for error in an output color of a colored output image in a marking device intended to match a desired image, comprising: detecting a current output color in the output image with a color sensing device; obtaining a corresponding target color in device independent space under standard conditions, determining a difference between the current output color and the corresponding target color; and automatically setting at least one marking device tone reproduction curve for a next output color based on the difference between the current output color and the corresponding target color to minimize the difference between the next output color and the corresponding target color.
Claim 4
Independent Claim
109 words
A method of correcting for error in an output color of a colored output image in a marking device intended to match a desired image, comprising: detecting a current output color in the output image with a color sensing device; obtaining a corresponding target color in device independent space under standard conditions, determining a difference between the current output color and the corresponding target color; and automatically setting at least one marking device tone reproduction curve for a next output color based on the difference between the current output color and the corresponding target color to minimize the difference between the next output color and the corresponding target color.
Claim 5
Dependent Claim
24 words
The method of claim 2 , wherein the determining step includes obtaining the corresponding target color by accessing target color values stored in memory.
Claim 6
Dependent Claim
13 words
The method of claim 3 , wherein obtaining includes accessing a look-up table.
Claim 7
Dependent Claim
18 words
The method of claim 3 , wherein obtaining includes accessing a look-up table of target color spectra values.
Claim 8
Dependent Claim
28 words
The method of claim 2 , wherein the at least one marking device tone reproduction curve is a tone reproduction curve corrected for variability of the marking device.
Claim 9
Dependent Claim
40 words
The method of claim 2 , wherein the step of setting at least one marking device tone reproduction curve includes outputting a corrected tone reproduction curve for at least one color separation that the marking device is capable of outputting.
Claim 10
Dependent Claim
20 words
The method of claim 7 , wherein the step of determining includes obtaining at least one nominal tone reproduction curve.
Claim 11
Dependent Claim
38 words
The method of claim 8 , wherein the step of determining includes summing the at least one nominal tone reproduction curve and the processed difference between the current output color and the corresponding output color under standard conditions.
Claim 12
Dependent Claim
27 words
The method of claim 7 , wherein the step of determining includes transforming spectra of the current output color from device independent space to control parameter space.
Claim 13
Dependent Claim
26 words
The method of claim 7 , wherein the step of determining includes transforming spectra of the target color from device independent space to control parameter space.
Claim 14
Dependent Claim
62 words
The method of claim 7 , wherein the current output color and the corresponding target color under standard conditions are expressed in control parameter space, and the step of determining the difference includes calculating an error signal equal to the difference between the current output color in control parameter space and the corresponding target color under standard conditions in control parameter space.
Claim 15
Dependent Claim
25 words
The method of claim 12 , wherein the step of setting includes obtaining a weighted error by multiplying the error signal by a gain matrix.
Claim 16
Dependent Claim
22 words
The method of claim 13 , wherein the step of setting includes integrating the weighted error with respect to an iteration number.
Claim 17
Dependent Claim
53 words
The method of claim 14 , wherein the step of determining includes obtaining at least one nominal tone reproduction curve, and wherein the step of setting includes summing the integrated weighted error with the at least one tone reproduction curve to yield a corrected tone reproduction curve as the marking device input-output relationship.
Claim 18
Dependent Claim
29 words
The method of claim 2 , further comprising the step of outputting the at least one marking device tone reproduction curve to controllers operating in a time hierarchical mode.
Claim 19
Dependent Claim
21 words
The method of claim 2 , wherein the steps of detecting, determining and setting occur while the marking device is outputting.
Claim 20
Dependent Claim
23 words
The method of claim 2 , wherein determining includes obtaining target color values under current conditions from test patches in an output image.
Claim 21
Independent Claim
110 words
An apparatus for correcting error in an output color of a colored output image intended to match a desired image, comprising: a color sensing device capable of sensing a current output color in the output image; and a controller linked to the color sensing device that determines a difference between the current output color and a corresponding target color in device independent space under standard conditions, and automatically sets at least one marking device tone reproduction curve of a next output color based on the difference between the current output color and the corresponding target color to minimize the difference between the next output color and the corresponding target color.
Claim 22
Independent Claim
110 words
An apparatus for correcting error in an output color of a colored output image intended to match a desired image, comprising: a color sensing device capable of sensing a current output color in the output image; and a controller linked to the color sensing device that determines a difference between the current output color and a corresponding target color in device independent space under standard conditions, and automatically sets at least one marking device tone reproduction curve of a next output color based on the difference between the current output color and the corresponding target color to minimize the difference between the next output color and the corresponding target color.
Claim 23
Dependent Claim
35 words
The apparatus of claim 19 , wherein the controller is linked to a memory containing target colors under standard conditions, and the controller accesses the memory to obtain the corresponding target color under standard conditions.
Claim 24
Dependent Claim
24 words
The apparatus of claim 20 , wherein the memory is a look-up table containing target colors under standard conditions expressed in device independent space.
Claim 25
Dependent Claim
26 words
The apparatus of claim 20 , wherein the memory is a look-up table containing target colors under standard conditions expressed in device independent space trichometric quantities.
Claim 26
Dependent Claim
26 words
The apparatus of claim 20 , wherein the memory is a look-up table containing target colors under standard conditions expressed in device independent space spectral quantities.
Claim 27
Dependent Claim
29 words
The apparatus of claim 19 , wherein the controller includes a transformation block to transform spectra of the current output color from device independent space to control parameter space.
Claim 28
Dependent Claim
31 words
The apparatus of claim 19 , wherein the controller includes a transformation block to transform spectra of the target color under standard conditions from device independent space to control parameter space.
Claim 29
Dependent Claim
43 words
The apparatus of claim 19 , wherein the controller includes a summing node that computes an error equal to the difference between the current output color expressed in control parameter space and the target color under standard conditions expressed in control parameter space.
Claim 30
Dependent Claim
25 words
The apparatus of claim 26 , wherein the controller includes a multiplier that calculates a weighted error by multiplying the error by a gain matrix.
Claim 31
Dependent Claim
23 words
The apparatus of claim 27 , wherein the controller includes an integrator that integrates the weighted error with respect to an iteration number.
Claim 32
Dependent Claim
37 words
The apparatus of claim 28 , wherein the summing node is a first summing node and the controller includes a second summing node that sums the integrated weighted error with nominal tone reproduction curves retrieved from memory.
References Cited (Backward Citations)
US3870968A
Cited
US4205257A
Cited
US4403866A
Cited
US4887217A
Cited
US4853639A
Cited
US4724461A
Cited
US5345315A
Cited
US5045882A
Cited
US5003327A
Cited
US5544258A
Cited
JPH04314768A
Cited
US5481380A
Cited
US5243383A
Cited
US5673075A
Cited
US5664072A
Cited
US5559173A
Cited
US5881209A
Cited
US5642202A
Cited
US5694224A
Cited
US5662044A
Cited
US5822079A
Cited
US5734407A
Cited
US5739927A
Cited
US5696889A
Cited
US5748221A
Cited
US5812903A
Cited
US5717978A
Cited
US5749019A
Cited
US5708916A
Cited
US5884118A
Cited
US5749021A
Cited
US5754918A
Cited
US6002842A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2004-05-21 | 2004-11-20 | 2005-05-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-05-21 | 2008-11-20 | 2009-05-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-05-21 | 2012-11-20 | 2013-05-22 | $7700.00 | Window Closed / Lapsed |