JP2008193428A5

JP2008193428A5 -

Info

Publication number: JP2008193428A5
Application number: JP2007026068A
Authority: JP
Filing date: 2007-02-05
Publication date: 2010-03-25
Anticipated expiration: 2027-02-05

Claims

An image processing method for calibrating image formation of an image forming apparatus,
An image forming step of forming a transfer image for transfer to a recording medium based on the input image signal value;
A density detecting step of detecting an image density of the transfer image using a density sensor;
Deriving a correlation between the image density detected in the density detection step and the input image signal value;
By recording a black monochrome patch and a plurality of types of process gray patches on a recording medium using the correlation, and reading those patches recorded on the recording medium using a color sensor, A color determination step of determining a process gray of a color closest to a black single color among the plurality of types of process gray;
A calculation step of calculating an input image signal value for realizing a process gray determined to be closest to a black single color in the color determination step;
An update step for updating the correlation so that the ideal value on the color separation table for realizing black monochrome corresponds to the input image signal value calculated in the calculation step;
An image processing method comprising:

Before the color determination step, further comprising the previous concentration control process when performed the crab according to a new concentration control process should whether the determination step,
When it is determined that a new density control process is necessary in the determination process, the image forming process and the density detection process are performed before the color determination process, and a new density control process is performed in the determination process. 2. The image processing method according to claim 1, wherein if it is determined that the color determination step is not necessary, the color determination step is performed without performing the image forming step and the density detection step.

The image processing method according to claim 1, wherein the correlation is a calibration table.

The image processing method according to claim 1, wherein the target gamma is updated using the correlation updated in the updating step.

The image processing method according to claim 1, wherein correction data for correcting the density detected in the density detection step is updated using the updated correlation.

The color determination step includes colors of a plurality of process gray patches formed by mixing a color of a patch formed of a black single color material and three color materials of cyan, magenta, and yellow at different ratios. 2. The input image signal values of cyan, magenta, and yellow necessary for forming a process gray patch that is the same color as a single black color are estimated based on the detection result. Image processing method.

The image processing method according to claim 2, wherein the determination step is performed based on the number of recording media on which an image is formed after the immediately preceding density control process.

The image processing method according to claim 2, wherein the determination step is performed based on the number of processed image forming instructions after the immediately preceding density control process.

The image processing method according to claim 2, wherein the determination is performed based on a time elapsed after the immediately preceding density control process.

Image forming means for forming a transfer image for transfer to a recording medium based on the input image signal value;
A density detection means for detecting an image density of the transfer image using a density sensor;
Means for deriving a correlation between the image density detected by the density detection means and the input image signal value;
By recording a black monochrome patch and a plurality of types of process gray patches on a recording medium using the correlation, and reading those patches recorded on the recording medium using a color sensor, A color determination means for determining a process gray of a color closest to a black single color among the plurality of types of process gray;
Calculating means for calculating an input image signal value for realizing a process gray determined to be closest to the black single color in the color determining means;
Updating means for updating the correlation so that the ideal value on the color separation table for realizing black monochrome corresponds to the input image signal value calculated by the calculating means;
Have
The image forming apparatus forms an image while correcting an input image signal value using the correlation updated by the updating unit.

A program for calibrating image formation of an image forming apparatus,
An image forming step of forming a transfer image for transfer to a recording medium based on the input image signal value;
A density detecting step of detecting an image density of the transfer image using a density sensor;
Deriving a correlation between the image density detected in the density detection step and the input image signal value;
By recording a black monochrome patch and a plurality of types of process gray patches on a recording medium using the correlation, and reading those patches recorded on the recording medium using a color sensor, A color determination step of determining a process gray of a color closest to a black single color among the plurality of types of process gray;
A calculation step of calculating an input image signal value for realizing a process gray determined to be closest to a black single color in the color determination step;
An update step for updating the correlation so that the ideal value on the color separation table for realizing black monochrome corresponds to the input image signal value calculated in the calculation step;
A program that causes a computer to execute.