Patent US6972871B2 successfully refreshed from Google Patents.
US6972871B2
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Color image forming device and method
Assignee: Fujifilm Business Innovation Corp
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Filing: 2001-09-27
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Granted: 2005-12-06
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Expires: 2021-09-27
Abstract
Abstract A color image forming device and method prevent occurrence of pile height moires specific to electrophotographic images in low-frequency areas and conventional moires in a digital screen set of four colors. In the color image forming device, by at least one of a halftone generating part and scanning signal forming unit in an image processing unit, differences among screen angles of three dot patterns corresponding to cyan, magenta and black toner images are in the range about 25 to 40 degrees, preferably 30 degrees; the screen angle of a first dot pattern corresponding to a yellow toner image is made equal to that of a second dot pattern corresponding to the toner image of one of cyan, magenta and black; and the screen of the first dot pattern is brought about 150 to 210 degrees, preferably about 180 degrees out of phase with the screen of the second dot pattern.
Inventors
- 👤 Yu Tsuda
- 👤 Osamu Ide
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 12:06
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/46; H04N1/52
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
160 words
A color image forming device which forms an output image corresponding to input image data on a recording medium using pigments of four colors cyan, magenta, yellow, and black, the color image forming device comprising: a color separation part that generates color image data separated by colors corresponding to the pigments of the four colors from the input image data, or obtains, as the input image data, color image data separated by colors corresponding to the pigments of the four colors; and an image forming part that, of the color image data generated or obtained by the color separation part, makes a screen angle of a first output image corresponding to the color image data of yellow identical with a screen angle of a second output image corresponding to the color image data of one of cyan, magenta, and black, and brings the screen of the first output image out of phase with the screen of the second output image.
Claim 2
Dependent Claim
160 words
A color image forming device which forms an output image corresponding to input image data on a recording medium using pigments of four colors cyan, magenta, yellow, and black, the color image forming device comprising: a color separation part that generates color image data separated by colors corresponding to the pigments of the four colors from the input image data, or obtains, as the input image data, color image data separated by colors corresponding to the pigments of the four colors; and an image forming part that, of the color image data generated or obtained by the color separation part, makes a screen angle of a first output image corresponding to the color image data of yellow identical with a screen angle of a second output image corresponding to the color image data of one of cyan, magenta, and black, and brings the screen of the first output image out of phase with the screen of the second output image.
Claim 3
Dependent Claim
46 words
The color image forming device according to claim 1 , wherein the image forming part sets the differences among the screen angles of three output images corresponding to the color image data of cyan, magenta, and black in the range of about 25 to 40 degrees.
Claim 4
Dependent Claim
134 words
The color image forming device according to claim 1 , wherein the image forming part comprises a halftone generation part that compares data for creating dot patterns having periodic structures corresponding to four colors cyan, magenta, yellow, and black with the four pieces of color image data generated or obtained by the color separation part, and generates halftone image data, and an image forming part that forms image data for image output, based on the halftone image data generated by the halftone generation part, wherein the screen angles and phases of the first and second output images, or the differences among the screen angles of output images corresponding to the color image data of cyan, magenta, and black are set by at least one of the halftone generation part and the image forming part.
Claim 5
Dependent Claim
23 words
The color image forming device according to claim 1 , wherein the second output image corresponds to the color image data of black.
Claim 6
Dependent Claim
79 words
The color image forming device according to claim 1 , wherein one of main spectrums of the screen of an output image corresponding to the color image data of yellow or black is the same as a differential spectrum between one of main spectrums of the screen of an output image corresponding to the color image data of cyan and one of main spectrums of the screen of an output image corresponding to the color image data of magenta.
Claim 7
Dependent Claim
38 words
The color image forming device according to claim 1 , wherein each of the screens of four output images corresponding to the color image data of cyan, magenta, yellow, and black has 200 lines or more per inch.
Claim 8
Dependent Claim
32 words
The color image forming device according to claim 1 , wherein the color separation part generates or obtains the color image data of black only in a low-brightness and low-chroma color area.
Claim 9
Dependent Claim
40 words
The color image forming device according to claim 7 , wherein the color separation part generates or obtains the color image data of black only in a area where C* is 40 or less, and L* is 40 or less.
Claim 10
Dependent Claim
109 words
A color image forming method which forms an output image corresponding to input image data on a recording medium using pigments of four colors cyan, magenta, yellow, and black, the color image forming method comprising the steps of: making a screen angle of a first output image corresponding to the color image data of yellow identical with a screen angle of a second output image corresponding to the color image data of one of cyan, magenta, and black; and bringing the screen of the first output image about 150 degrees or more and about 210 degrees or less out of phase with the screen of the second output image.
Claim 11
Dependent Claim
109 words
A color image forming method which forms an output image corresponding to input image data on a recording medium using pigments of four colors cyan, magenta, yellow, and black, the color image forming method comprising the steps of: making a screen angle of a first output image corresponding to the color image data of yellow identical with a screen angle of a second output image corresponding to the color image data of one of cyan, magenta, and black; and bringing the screen of the first output image about 150 degrees or more and about 210 degrees or less out of phase with the screen of the second output image.
Claim 12
Dependent Claim
45 words
The color image forming method according to claim 9 , comprising the step of: setting the differences among the screen angles of three output images corresponding to the color image data of cyan, magenta, and black in the range of about 25 to 40 degrees.
Claim 13
Dependent Claim
79 words
The color image forming method according to claim 9 , wherein one of main spectrums of the screen of an output image corresponding to the color image data of yellow or black is the same as a differential spectrum between one of main spectrums of the screen of an output image corresponding to the color image data of cyan and one of main spectrums of the screen of an output image corresponding to the color image data of magenta.
Claim 14
Dependent Claim
30 words
The color image forming method according to claim 9 , forming an output image corresponding to the color image data of black only in a low-brightness and low-chroma color area.
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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) | 2008-12-05 | 2009-06-06 | 2009-12-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2012-12-05 | 2013-06-06 | 2013-12-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2016-12-05 | 2017-06-06 | 2017-12-06 | $7700.00 | Window Closed / Lapsed |