Patent US5870530A successfully refreshed from Google Patents.
US5870530A
Expired / Lapsed
US
⏱️ 0.0 years remaining
System for printing color images with extra colorants in addition to primary colorants
Assignee: Xerox Corp
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Filing: 1996-09-27
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Granted: 1999-02-09
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Expires: 2016-09-27
Abstract
Abstract In a "hi-fi" color printing system, wherein colorants of secondary colors beyond the regular CMYK primary colorants are available, the colorants of the secondary colors are substituted for combinations of the primary colorants in order to obtain a full color gamut. The functions by which colorants of the secondary colors are substituted for primary colorant are non-linear through a path in the color space.
Inventors
- 👤 Raja Balasubramanian
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 23:37
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/46; H04N1/54
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
131 words
In a digital printing apparatus capable of printing a desired color as a combination of a subset of a set of colorants, the set of colorants comprising at least first and second colorants and an intermediate colorant disposed between the first and second colorants in color space, the intermediate colorant being chromatic and disposed at an edge of a color gamut which the apparatus is capable of printing, a method of converting color primary image signals operative of the first colorant and second colorant to hi-fi image signals operative of the first colorant, second colorant, and intermediate colorant, comprising the step of: performing a substitution of a combination of the primary image signals with an intermediate image signal representative of the intermediate colorant according to a non-linear function in reflectance coordinates.
Claim 2
Dependent Claim
131 words
In a digital printing apparatus capable of printing a desired color as a combination of a subset of a set of colorants, the set of colorants comprising at least first and second colorants and an intermediate colorant disposed between the first and second colorants in color space, the intermediate colorant being chromatic and disposed at an edge of a color gamut which the apparatus is capable of printing, a method of converting color primary image signals operative of the first colorant and second colorant to hi-fi image signals operative of the first colorant, second colorant, and intermediate colorant, comprising the step of: performing a substitution of a combination of the primary image signals with an intermediate image signal representative of the intermediate colorant according to a non-linear function in reflectance coordinates.
Claim 3
Dependent Claim
22 words
The method of claim 1, wherein the substitution step includes entering the primary image signals into an algorithm including a logarithmic function.
Claim 4
Dependent Claim
21 words
The method of claim 1, wherein the substitution step includes converting the primary image signals from reflectance coordinates to density coordinates.
Claim 5
Dependent Claim
22 words
The method of claim 3, wherein the substitution step includes performing an undercolor removal calculation on an image signal in density coordinates.
Claim 6
Dependent Claim
36 words
The method of claim 3, further comprising the steps of converting the substituted image signals from density coordinates to reflectance coordinates; and operating a digital printing apparatus according to the substituted image signals in reflectance coordinates.
Claim 7
Dependent Claim
206 words
In a digital printing apparatus capable of printing a desired color as a combination of a subject of a set of colorants, the set of colorants comprising at least first and second primary colorants and an intermediate colorant disposed between the first and second colorants in color space, the intermediate colorant being chromatic and disposed at an edge of a color gamut which the apparatus is capable of printing, a method of converting color primary image signals operative of the first colorant and second colorant to hi-fi signals operative of the first colorant, second colorant, and intermediate colorant, comprising the steps of: for obtaining colors in a first portion of color space between the first colorant and the second colorant, combining only the first colorant and the second colorant, a proportion of the first colorant to the second colorant varying in a linear function with varying distance in color space from the first colorant; and for obtaining colors in a second portion of color space between the first colorant and the second colorant, combining the second colorant with the intermediate colorant, a substitution of the second colorant and the intermediate colorant varying in a non-linear function with varying distance in color space from the second colorant.
Claim 8
Dependent Claim
206 words
In a digital printing apparatus capable of printing a desired color as a combination of a subject of a set of colorants, the set of colorants comprising at least first and second primary colorants and an intermediate colorant disposed between the first and second colorants in color space, the intermediate colorant being chromatic and disposed at an edge of a color gamut which the apparatus is capable of printing, a method of converting color primary image signals operative of the first colorant and second colorant to hi-fi signals operative of the first colorant, second colorant, and intermediate colorant, comprising the steps of: for obtaining colors in a first portion of color space between the first colorant and the second colorant, combining only the first colorant and the second colorant, a proportion of the first colorant to the second colorant varying in a linear function with varying distance in color space from the first colorant; and for obtaining colors in a second portion of color space between the first colorant and the second colorant, combining the second colorant with the intermediate colorant, a substitution of the second colorant and the intermediate colorant varying in a non-linear function with varying distance in color space from the second colorant.
Claim 9
Dependent Claim
68 words
The method of claim 6, further comprising the step of for obtaining colors in a third portion of color space between the first colorant and the second colorant, combining the first colorant and the second colorant with the intermediate colorant, a substitution of at least one of the first colorant and second colorant varying in a non-linear function with varying distance in color space from the first colorant.
References Cited (Backward Citations)
US4275413A
Cited
US4500919A
Cited
US4812899A
Cited
US4893179A
Cited
US5047844A
Cited
US5136372A
Cited
US5087126A
Cited
US5208663A
Cited
US5140411A
Cited
US5077604A
Cited
US5528386A
Cited
US5633953A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-02-08 | 2002-08-10 | 2003-02-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-02-08 | 2006-08-10 | 2007-02-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-02-08 | 2010-08-10 | 2011-02-09 | $7700.00 | Window Closed / Lapsed |