Back to results
US 2006/0066910 A1Published application
Image forming apparatus, image forming method, and recording medium
OwnerKei Yasutomiinventor
Life of this patent
Estimating the term…
Abstract
An image forming apparatus is disclosed. A color moire score calculator selects a combination (a dither set) of four dither matrices from plural types of dither matrices stored in a dither matrix storage, and calculates color moire scores of secondary colors and tertiary colors. Dither processing is performed in a pseudo-halftoning part using a dither set having a preferable color moire score.
Claims26
An image forming apparatus that superposes color material images of four colors of cyan, magenta, yellow and black on a predetermined medium using color materials of the four colors,
- wherein each of the color material images of the four colors has a linear periodic structure represented by a function whose reflectance distribution formed by periodic adhesion of a corresponding color material is normalized at 1.0;
- when an intensity and a spatial frequency of a beat calculated by multiplication of each of combinations of spatial frequency components between two functions corresponding to two of the four colors are defined as P2i and f2i (suffix i identifying each of the combinations of the spatial frequency components between the two colors), respectively, a relational expression P2i·VTF(f2i)≦0.015 (VTF(f) representing a visual transfer function) is satisfied by each of six combinations of two colors selected from the four colors;
- and
- when the intensity and the spatial frequency of a beat calculated by multiplication of each of combinations of spatial frequency components among three functions corresponding to three of the four colors are defined as P3j and f3j (the suffix j identifying each of the combinations of the spatial frequency components among the three colors), respectively, a relational expression P3j·VTF(f3j)≦0.015 is satisfied by each of four combinations of three colors selected from the four colors.
1 more element
An electrophotographic image forming apparatus that superposes toner images of four colors of cyan, magenta, yellow and black on a predetermined medium using power toners of the four colors,
- wherein each of the toner images of the four colors has a linear periodic structure represented by a function whose reflectance distribution formed by periodic adhesion of a corresponding toner is normalized at 1.0;
- when an intensity and a spatial frequency of a beat calculated by multiplication of each of combinations of spatial frequency components between the two functions corresponding to two of the four colors are defined as P2i and f2i (suffix i identifying each of the combinations of the spatial frequency components between the two colors), respectively, a relational expression P2i·VTF(f2i)≦0.015 (VTF(f) representing a visual transfer function) is satisfied by each of six combinations of two colors selected from the four colors;
- and
- when the intensity and the spatial frequency of a beat calculated by multiplication of each of combinations of spatial frequency components among three functions corresponding to three of the four colors are defined as P3j and f3j (the suffix j identifying each of the combinations of the spatial frequency components among the three colors), respectively, a relational expression P3j·VTF(f3j)≦0.015 is satisfied by each of four combinations of three colors selected from the four colors.
1 more element
An image forming method for superposing color material images of four colors of cyan, magenta, yellow and black on a predetermined medium using color materials of the four colors,
- wherein each of the color material images of the four colors has a linear periodic structure represented by a function whose reflectance distribution formed by periodic adhesion of a corresponding color material is normalized at 1.0;
- when an intensity and a spatial frequency of a beat calculated by multiplication of each of combinations of spatial frequency components between two functions corresponding to two of the four colors are defined as P2i and f2i (suffix i identifying each of the combinations of the spatial frequency components between the two colors), respectively, a relational expression P2i·VTF(f2i)≦0.015 (VTF(f) representing a visual transfer function) is satisfied by each of six combinations of two colors selected from the four colors;
- and
- when the intensity and the spatial frequency of a beat calculated by multiplication of each of combinations of spatial frequency components among three functions corresponding to three of the four colors are defined as P3j and f3j (the suffix j identifying each of the combinations of the spatial frequency components among the three colors), respectively, a relational expression P3j·VTF(f3j)≦0.015 is satisfied by each of four combinations of three colors selected from the four colors.
1 more element
A computer-readable recording medium storing program codes for performing an image forming method for superposing color material images of four colors of cyan, magenta, yellow and black on a predetermined medium using color materials of the four colors,
- wherein each of the color material images of the four colors has a linear periodic structure represented by a function whose reflectance distribution formed by periodic adhesion of a corresponding color material is normalized at 1.0;
- when an intensity and a spatial frequency of a beat calculated by multiplication of each of combinations of spatial frequency components between two functions corresponding to two of the four colors are defined as P2i and f2i (suffix i identifying each of the combinations of the spatial frequency components between the two colors), respectively, a relational expression P2i·VTF(f2i)≦0.015 (VTF(f) representing a visual transfer function) is satisfied by each of six combinations of two colors selected from the four colors;
- and
- when the intensity and the spatial frequency of a beat calculated by multiplication of each of combinations of spatial frequency components among three functions corresponding to three of the four colors are defined as P3j and f3j (the suffix j identifying each of the combinations of the spatial frequency components among the three colors), respectively, a relational expression P3j·VTF(f3j)≦0.015 is satisfied by each of four combinations of three colors selected from the four colors.
1 more element
Dependencies are inferred from the claim text.