Patent US6198549B1 successfully refreshed from Google Patents.
US6198549B1
Expired / Lapsed
US
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System, method, program, and print pattern for performing registration calibration for printers by measuring density
Assignee: Ricoh Co Ltd
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Filing: 1997-07-31
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Granted: 2001-03-06
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Expires: 2017-07-31
Abstract
Abstract The system, method, program, and print pattern of this invention allows print misregistration to be detected and controlled through density measurements. A special print pattern is used for which a correlation between a density measurement of the print pattern and an amount of misregistration can be made. Initially, for a given printer, and for each printing station within the printer, the special print pattern is printed using two printing stations at varying amounts of misregistration of one of the printing stations. The density of each special print pattern printed at the varied amount of misregistration is measured. A correlation is made between density and amount of misregistration of the one printing station relative to the other printing station. Whenever misregistration is desired to be determined, the special print pattern is printed, the density is measured, and the correlation is applied to the measured density to determine a misregistration amount.
Inventors
- 👤 William Chesley Decker
- 👤 Ho Chong Lee
- 👤 Jack Louis Zable
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 14:58
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/46; H04N1/50; H04N1/506; G; G03; G03G; G03G15/00; G03G15/01; G03G15/0142; G03G15/0178; G03G15/0194; G03G2215/00; G03G2215/00362; G03G2215/00535; G03G2215/00556; G03G2215/00586; G03G2215/01; G03G2215/0103; G03G2215/0119; G03G2215/0151; G03G2215/0158; G03G2215/0161
Claims Analysis
Total Claims: 33
Claim 1
Independent Claim
153 words
A method of determining misregistration of a printer, the method comprising: printing multiple instances of a first and second repeated patterns, wherein for each printing instance, the first and second repeated patterns are printed at a different predetermined misregistration; measuring densities of the first and second repeated patterns for each printing instance; determining a density difference for each printing instance by subtracting the measured density of the first and second repeated patterns for the printing instance; determining a characteristic curve providing a relationship of the determined density differences to the predetermined misregistrations; calculating a correlation from the determined characteristic curve, wherein the correlation is between the density difference and predetermined misregistration; printing at least one additional print pattern after calculating the correlation; measuring density of the at least one additional print pattern; determining an amount of misregistration by applying the correlation to the measured density of the at least one additional print pattern.
Claim 2
Independent Claim
153 words
A method of determining misregistration of a printer, the method comprising: printing multiple instances of a first and second repeated patterns, wherein for each printing instance, the first and second repeated patterns are printed at a different predetermined misregistration; measuring densities of the first and second repeated patterns for each printing instance; determining a density difference for each printing instance by subtracting the measured density of the first and second repeated patterns for the printing instance; determining a characteristic curve providing a relationship of the determined density differences to the predetermined misregistrations; calculating a correlation from the determined characteristic curve, wherein the correlation is between the density difference and predetermined misregistration; printing at least one additional print pattern after calculating the correlation; measuring density of the at least one additional print pattern; determining an amount of misregistration by applying the correlation to the measured density of the at least one additional print pattern.
Claim 3
Dependent Claim
38 words
The method of claim 1 , wherein applying the correlation to the measured density of the at least one additional print pattern comprises multiplying the correlation times the density of the measured at least one additional print pattern.
Claim 4
Dependent Claim
57 words
The method of claim 2 , wherein the at least one additional print pattern comprises third and fourth print patterns, further comprising measuring a density difference of the third and fourth print patterns, wherein determining the amount of misregistration using multiplication is calculated as follows: correlation * (measured density difference of the third and fourth print patterns).
Claim 5
Dependent Claim
49 words
The method of claim 1 , wherein the first and second print patterns are printed by a first and second printing stations, wherein the at least one additional print pattern is printed by the second printing station, and wherein the determined misregistration indicates misregistration for the second printing station.
Claim 6
Dependent Claim
30 words
The method of claim 1 , wherein printing the pattern comprises printing the pattern on successive pages and wherein measuring the density further comprises averaging the density over successive pages.
Claim 7
Dependent Claim
25 words
The method of claim 1 , wherein the first print pattern, second print patter and at least one additional print pattern comprise a same pattern.
Claim 8
Dependent Claim
21 words
The method of claim 1 , wherein the first print pattern and the second print pattern comprise a same print pattern.
Claim 9
Dependent Claim
222 words
The method of claim 1 , wherein the first print pattern comprises a repeatedly printed first printed bar, wherein during each print repetition, the first printed bar is printed to have a first specified width of a first color from a first printing station, followed by a first space of a second specified width, and repeating the first printed bar and first space for at least a minimum distance; and wherein the second print pattern comprises a repeatedly printed second printed bar, wherein during each print repetition, the second printed bar is printed to have the first specified width of a second color from a second printing station, followed by a second specified width superimposed on the first printed bar and the first space but offset, by a predetermined amount in a predetermined direction, from the first printed bar and first space, and repeating the second printed bar and second space with the offset by the predetermined amount in the predetermined direction for the minimum distance; whereby superimposing and offsetting the repeatedly printed second printed bar and the second space on top of the first printed bar and first space results in a repeated white space pattern having a resulting width, wherein the resulting width is repeated between every two instances of the second printed bar superimposed on the first printed par.
Claim 10
Dependent Claim
45 words
The method of claim 8 , wherein the first and second specified widths are small enough so that at least one complete pattern sequence of the repeating print pattern is smaller than an aperture of a densitometer used to measure density of the repeating pattern.
Claim 11
Independent Claim
168 words
A system for determining misregistration of a printer, the system comprising: means for printing multiple instances of a first and second repeated patterns with the printer, wherein for each printing instance, the first and second repeated patterns are printed at a different predetermined misregistration; means for measuring densities of first and second repeated patterns for each printing instance; determining a density difference for each printing instance by subtracting the measured density of the first and second repeated patterns for the printing instance; determining a characteristic curve providing a relationship of the determined density differences to the predetermined misregistrations; means for calculating a correlation from the determined characteristic curve, wherein the correlation is between the density difference and predetermined misregistration; means for printing at least one additional print pattern after calculating the correlation; means for measuring density of the at least one additional print pattern; and means for applying the correlation to the measured density of the at least one additional print pattern to determine an amount of misregistration.
Claim 12
Independent Claim
168 words
A system for determining misregistration of a printer, the system comprising: means for printing multiple instances of a first and second repeated patterns with the printer, wherein for each printing instance, the first and second repeated patterns are printed at a different predetermined misregistration; means for measuring densities of first and second repeated patterns for each printing instance; determining a density difference for each printing instance by subtracting the measured density of the first and second repeated patterns for the printing instance; determining a characteristic curve providing a relationship of the determined density differences to the predetermined misregistrations; means for calculating a correlation from the determined characteristic curve, wherein the correlation is between the density difference and predetermined misregistration; means for printing at least one additional print pattern after calculating the correlation; means for measuring density of the at least one additional print pattern; and means for applying the correlation to the measured density of the at least one additional print pattern to determine an amount of misregistration.
Claim 13
Dependent Claim
46 words
The printer of claim 10 wherein the means for applying the correlation to the measured density of the at least one additional print pattern to determine the amount of misregistration comprises multiplying the correlation times the measured density of the at least one additional print pattern.
Claim 14
Dependent Claim
23 words
The printer of claim 11 further comprising means for causing an adjustment of registration as a result of the determined amount of misregistration.
Claim 15
Dependent Claim
14 words
The printer of claim 11 further comprising means for displaying the amount of misregistration.
Claim 16
Dependent Claim
26 words
The printer of claim 11 further comprising means for querying an operator whether the printer should automatically correct for misregistration by the determined amount of misregistration.
Claim 17
Dependent Claim
59 words
The system of claim 11 , wherein the at least one additional print pattern comprises third and fourth print patterns, further comprising measuring a density difference of the third and forth print patterns, wherein the means for determining the amount of misregistration using multiplication uses the equation: correlation * (measured density difference of the third and fourth print patterns).
Claim 18
Dependent Claim
48 words
The system of claim 10 implemented in a printer, wherein the means for measuring the print patterns comprises a densitometer in the printer, and wherein the means for using the measured densities to determine the amount of misregistration is implemented in a computer program resident in the printer.
Claim 19
Dependent Claim
25 words
The system of claim 10 , wherein the first pint pattern, second print pattern and at least one additional print pattern comprise a same pattern.
Claim 20
Dependent Claim
21 words
The system of claim 10 , wherein the first print pattern and the second print pattern comprise a same print pattern.
Claim 21
Dependent Claim
222 words
The system of claim 10 , wherein the first print pattern comprises a repeatedly printed first printed bar, wherein during each print repetition, the first printed bar is printed to have a first specified width of a first color from a first printing station, followed by a first space of a second specified width, and repeating the first printed bar and first space for at least a minimum distance; and wherein the second print pattern comprises a repeatedly printed second printed bar, wherein during each print repetition, the second printed bar is printed to have the first specified width of a second color from a second printing station, followed by a second specified width superimposed on the first printed bar and the first space but offset, by a predetermined amount in a predetermined direction, from the first printed bar and first space, and repeating the second printed bar and second space with the offset by the predetermined amount in the predetermined direction for the minimum distance; whereby superimposing and offsetting the repeatedly printed second printed bar and the second space on top of the first printed bar and first space results in a repeated white space pattern having a resulting width, wherein the resulting width is repeated between every two instances of the second printed bar superimposed on the first printed par.
Claim 22
Dependent Claim
158 words
A computer program, on a computer-usable medium, capable of causing a processor and printer to perform: printing multiple instances of a first and second repeated patterns, wherein for each printing instance, the first and second repeated patterns are printed at a different predetermined misregistration; measuring densities of the first and second repeated patterns for each printing instance; determining a density difference for each printing instance by subtracting the measured density of the first and second repeated patterns for the printing instance; determining a characteristic curve providing a relationship of the determined density differences to the predetermined misregistrations; calculating a correlation from the determined characteristic curve, wherein the correlation is between the density difference and predetermined misregistration; printing at least one additional print pattern after calculating the correlation; measuring density of the at least one additional print pattern; and determining an amount of misregistration by applying the correlation to the density of the at least one additional print pattern.
Claim 23
Dependent Claim
158 words
A computer program, on a computer-usable medium, capable of causing a processor and printer to perform: printing multiple instances of a first and second repeated patterns, wherein for each printing instance, the first and second repeated patterns are printed at a different predetermined misregistration; measuring densities of the first and second repeated patterns for each printing instance; determining a density difference for each printing instance by subtracting the measured density of the first and second repeated patterns for the printing instance; determining a characteristic curve providing a relationship of the determined density differences to the predetermined misregistrations; calculating a correlation from the determined characteristic curve, wherein the correlation is between the density difference and predetermined misregistration; printing at least one additional print pattern after calculating the correlation; measuring density of the at least one additional print pattern; and determining an amount of misregistration by applying the correlation to the density of the at least one additional print pattern.
Claim 24
Dependent Claim
38 words
The program of claim 20 , wherein applying the correlation to the measured density of the at least one additional print pattern comprises multiplying the correlation times the measured density of the at least one additional print pattern.
Claim 25
Dependent Claim
58 words
The computer program of claim 20 , wherein the at least one additional print pattern comprises a third and fourth print patterns, further comprising measuring density difference of the third and fourth print patterns, wherein determining the amount of misregistration using multiplication is calculated as follows: correlation * (measured density difference of the third and fourth print patterns).
Claim 26
Dependent Claim
18 words
The computer program of claim 20 wherein the computer program, on the computer-usable medium, resides in a printer.
Claim 27
Dependent Claim
22 words
The computer program of claim 20 wherein the computer program, on the computer-usable medium, resides in a computer external to the printer.
Claim 28
Dependent Claim
25 words
The computer program of claim 23 , further comprising means for causing the printer to automatically adjust registration according to the determined amount of misregistration.
Claim 29
Dependent Claim
15 words
The computer program of claim 20 further comprising means for displaying the determined of misregistration.
Claim 30
Dependent Claim
25 words
The program of claim 20 , wherein the first print pattern, second print pattern and at least one additional print pattern comprise a same pattern.
Claim 31
Dependent Claim
21 words
The program of claim 20 , wherein the first print pattern and the second print pattern comprise a same print pattern.
Claim 32
Dependent Claim
222 words
The program of claim 20 , wherein the first print pattern comprises a repeatedly printed first printed bar, wherein during each print repetition, the first printed bar is printed to have a first specified width of a first color from a first printing station, followed by a first space of a second specified width, and repeating the first printed bar and first space for at least a minimum distance; and wherein the second print pattern comprises a repeatedly printed second printed bar, wherein during each print repetition, the second printed bar is printed to have the first specified width of a second color from a second printing station, followed by a second specified width superimposed on the first printed bar and the first space but offset, by a predetermined amount in a predetermined direction, from the first printed bar and first space, and repeating the second printed bar and second space with the offset by the predetermined amount in the predetermined direction for the minimum distance; whereby superimposing and offsetting the repeatedly printed second printed bar and the second space on top of the first printed bar and first space results in a repeated white space pattern having a resulting width, wherein the resulting width is repeated between every two instances of the second printed bar superimposed on the first printed par.
Claim 33
Dependent Claim
45 words
The program of claim 29 , wherein the first and second specified widths are small enough so that at least one complete pattern sequence of the repeating print pattern is smaller than an aperture of a densitometer used to measure density of the repeating pattern.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2004-03-05 | 2004-09-04 | 2005-03-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-03-05 | 2008-09-04 | 2009-03-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-03-05 | 2012-09-04 | 2013-03-06 | $7700.00 | Window Closed / Lapsed |