Image processing method, program, image processing device, image forming device, and image forming system

• US 7,407,248 B2
• Filed: 10/16/2006
• Issued: 08/05/2008
• Est. Priority Date: 10/19/2005
• Status: Active Grant

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Hirano, Masanori, Yoshida, Masakazu, Hosaka, Shigetoshi
• Primary Examiner(s): Nguyen; Thinh H
• Application Number:
  US11/582,495
• Publication Number:
  US 20070085869A1
• Time in Patent Office: 659 Days
• Field of Search: 347/15, 347/43
• US Class Current: 347/15
• CPC Class Codes: B41J 19/142 with a reciprocating print head printing in both directions across the paper width
• CPC Class Codes: H04N 1/12 using the sheet-feed movement or the medium-advance or the drum-rotation movement as the slow scanning component, e.g. arrangements for the main-scanningsheet-feed movement by translatory movement of a flat picture-bearing surface H04N1/1008; main-scanning using oscillating or rotating mirrors H04N1/113; using multi-element arrays H04N1/19
• CPC Class Codes: H04N 1/128 using a scanning head arranged for linear reciprocating motion
• CPC Class Codes: H04N 1/1911 Simultaneously or substantially simultaneously scanning picture elements on more than one main scanning line, e.g. scanning in swaths
• CPC Class Codes: H04N 1/6022 Generating a fourth subtractive colour signal, e.g. under colour removal, black masking
• CPC Class Codes: H04N 2201/0468 Scanning in both of the two directions, e.g. during the forward and return movements

Abstract

An image processing method performs processing to generate image data based on input data and output the image data to an image forming device. The image forming device includes a printing head in which first nozzles for ejecting color ink drops are arranged in a symmetrical formation to forward and backward scanning directions and second nozzles for ejecting black or gray ink drops are arranged in an unsymmetrical formation with respect to the first nozzles. The image forming device is adapted to perform a uni-directional printing or a bidirectional printing with the printing head. In the image processing method, a black generation processing to the input data is performed, and when performing the black generation processing, a black-generation start level for the bidirectional printing is delayed to a shadow-side gradation level from a black-generation start level for the uni-directional printing.

Claims

1. An image processing method which performs processing to generate image data based on input data and output the image data to an image forming device, the image forming device including a printing head in which first nozzles for ejecting color ink drops are arranged in a symmetrical formation to forward and backward scanning directions and second nozzles for ejecting black or gray ink drops are arranged in an unsymmetrical formation with respect to the first nozzles for ejecting color ink drops, and adapted to perform a uni-directional printing or a bidirectional printing with the printing head, the image processing method comprising the steps of:

performing a black generation processing to the input data; and

delaying, when performing the black generation processing, a black-generation start level for the bidirectional printing to a shadow-side gradation level from a black-generation start level for the uni-directional printing.

2. The image processing method according to claim 1, wherein the black-generation start level for the bidirectional printing is delayed by one or more steps to the shadow-side gradation level from a multi-level transition level for using a color ink which causes a bidirectional color difference.

3. The image processing method according to claim 1, wherein, when the number of multiple values in multi-level gradation expression is equal to n (n>

3), the black-generation start level is set in a highlight-side level from a (n−

1)-th transition level.

4. The image processing method according to claim 1, wherein the image processing method is adapted to perform, when performing the uni-directional printing, the black generation processing in which the black-generation start level is delayed to the shadow-side gradation level.

5. The image processing method according to claim 1, wherein, when performing the bidirectional printing according to a kind of a sheet, it is determined whether the black generation processing in which the black-generation start level is delayed is performed or not.

6. The image processing method according to claim 1, wherein the black generation processing is contained in a color transform processing which performs a color transform processing to the input data.

7. A computer-readable program which, when executed by a computer, causes the computer to perform an image processing method which performs processing to generate image data based on input data and output the image data to an image forming device, the image forming device including a printing head in which first nozzles for ejecting color ink drops are arranged in a symmetrical formation to forward and backward scanning directions and second nozzles for ejecting black or gray ink drops are arranged in an unsymmetrical formation with respect to the first nozzles for ejecting color ink drops, and adapted to perform a uni-directional printing or a bidirectional printing with the printing head, the image processing method comprising the steps of:

performing a black generation processing to the input data; and

delaying, when performing the black generation processing, a black-generation start level for the bidirectional printing to a shadow-side gradation level from a black-generation start level for the uni-directional printing.

8. An image processing device which performs processing to generate image data based on input data and output the image data to an image forming device, the image forming device including a printing head in which first nozzles for ejecting color ink drops are arranged in a symmetrical formation to forward and backward scanning directions and second nozzles for ejecting black or gray ink drops are arranged in an unsymmetrical formation with respect to the first nozzles, and the image forming device being adapted to perform a uni-directional printing or a bidirectional printing with the printing head, and adapted to use multi-level gradation expression by changing ink drop size or using inks with a same hue and different optical densities,

wherein the image processing device comprises a control unit configured to perform a black generation processing to the input data, and to delay, when performing the black generation processing, a black-generation start level for the bidirectional printing to a shadow-side gradation level from a black-generation start level for the uni-directional printing.