Patent JPS58124902A successfully refreshed from Google Patents.
Patent EP0144188A2 successfully refreshed from Google Patents.
EP0144188A2
Expired / Lapsed
EP
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Copy density correction system
Assignee: Xerox Corp
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Filing: 1984-11-19
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Granted: —
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Expires: 2004-11-19
Abstract
Abstract A process for automatically correcting the tone and color reproduction characteristics of a color reproduction system is described. First, a test target containing a plurality of color patches of known or desired chromaticity coordinates and luminance is copied. Each patch on the copy is then analyzed by a colorimeter to generate sets of chromaticity coordinates for each patch. These are compared against the desired chromaticity coordinates for each color patch, and a set of tone reproduction corrections are generated and stored in a look-up table for each colorant in the color reproduction system.
Inventors
- 👤 Warren L. Rhodes
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-26 11:30
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/46; H04N1/56; H04N1/60; H04N1/603; H04N1/6033; H04N1/40; H04N1/407; H04N1/4076; H04N1/4078; H04N1/6016; H04N1/6019
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
67 words
A copy density correction system for adjusting the copy quality of a printing system comprising: means 12 for determining the density of a printed patch, means 13 responsive to the determined density for calculating the difference between the determined and desired density, and means 15 for adjusting the print density of the printing system so that the difference between the determined and desired density will be reduced.
Claim 2
Dependent Claim
67 words
A copy density correction system for adjusting the copy quality of a printing system comprising: means 12 for determining the density of a printed patch, means 13 responsive to the determined density for calculating the difference between the determined and desired density, and means 15 for adjusting the print density of the printing system so that the difference between the determined and desired density will be reduced.
Claim 3
Dependent Claim
13 words
The correction system of Claim 1 wherein said printing system uses one colorant.
Claim 4
Dependent Claim
56 words
The correction system of Claim 1 wherein said means for determining also determines the color of the printed patch, wherein said means for calculating calculates the difference between the determined and desired color and density, wherein said printing system uses two or more colorants, and wherein said means for adjusting adjusts the density of said colorants.
Claim 5
Dependent Claim
85 words
A copy density correction system for adjusting the copy quality of a printing system comprising: means 12 for determining the density of each of a plurality of printed patches which are various densities of the same color, means 13 responsive to the determined densities for calculating the difference between the determined and desired density over a range of densities, and means 15 for adjusting the print density over the range of densities so that the differences between the determined and desired densities will be reduced.
Claim 6
Dependent Claim
85 words
A copy density correction system for adjusting the copy quality of a printing system comprising: means 12 for determining the density of each of a plurality of printed patches which are various densities of the same color, means 13 responsive to the determined densities for calculating the difference between the determined and desired density over a range of densities, and means 15 for adjusting the print density over the range of densities so that the differences between the determined and desired densities will be reduced.
Claim 7
Dependent Claim
13 words
The correction system of Claim 4 wherein said printing system uses one colorant.
Claim 8
Dependent Claim
70 words
The correction system of Claim 4 wherein said means for determining also determines the color of said printed patches, wherein said means for calculating also calculates the differences between the determined and desired colors, wherein said printing system uses a plurality of colorants, and wherein said means for adjusting adjusts the amounts of colorants used so that the differences between the determined and desired colors and densities will be reduced.
Claim 9
Dependent Claim
106 words
A copy density correction system for adjusting the copy quality of a printing system which uses a plurality of colorants comprising: means for determining the color and density of each of a plurality of printed patches which vary in color and density, means responsive to the determined densities and colors for calculating the differences between the determined and desired densities and colors over a range of colors and densities, and means responsive to said determined densities and colors for adjusting the print density for each colorant over its range of densities so that the differences between the determined and desired densities and colors will be reduced.
Claim 10
Dependent Claim
106 words
A copy density correction system for adjusting the copy quality of a printing system which uses a plurality of colorants comprising: means for determining the color and density of each of a plurality of printed patches which vary in color and density, means responsive to the determined densities and colors for calculating the differences between the determined and desired densities and colors over a range of colors and densities, and means responsive to said determined densities and colors for adjusting the print density for each colorant over its range of densities so that the differences between the determined and desired densities and colors will be reduced.
Claim 11
Dependent Claim
31 words
The color correction system of Claims 1, 2, 3, 4, 5, 6 or 7 wherein predetermined values representative of the desired colors or densities are loaded into said means for calculating.
Claim 12
Dependent Claim
59 words
The color correction system of Claims 1, 2, 3, 4, 5, 6 or 7 wherein said printing system further comprises a reproduction scanner for reproducing printed patches from original patches, and wherein said means for determining further determines the color and density of said original patches corresponding to said printed patches to determine the desired color and density values.
Claim 13
Dependent Claim
40 words
The color correction system of Claims 4, 5, 6 or 7 wherein, for each printer colorant, the number of individual differences are formed into a smooth fitted curve before being used to adjust the print density over its entire range.
Claim 14
Dependent Claim
44 words
The color correction system of Claims 4, 5, 6 or 7 wherein, for each printer colorant, the number of individual differences are formed into a curve of any arbitrary function covering the entire range of densities before being used to adjust the print density.
Claim 15
Dependent Claim
62 words
The color correction system of Claims 1, 2, 3, 4, 5, 6 or 7 wherein said printing system uses a look-up table to convert the reproduction scanner outputs or the predetermined values into amounts of colorants used to print said printed patches, and wherein said means for adjusting adjusts the print density for each colorant by varying the values in said table.
References Cited (Backward Citations)
No citation records indexed.
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