Image forming apparatus and computer readable recording medium

Patent metadata

Field	Value
Publication number	US-9906689-B2
Application number	US-201715440024-A
Country	US
Kind code	B2
Filing date	Feb 23, 2017
Priority date	Feb 25, 2016
Publication date	Feb 27, 2018
Grant date	Feb 27, 2018

Abstract

An image forming apparatus includes: an image forming section; an image reading sensor and a colorimeter; a temperature sensor; a memory that stores a first color value and a second color value in a first color chart that has a larger number of patches than a second color chart; a processor that creates a scanner profile for converting a first color value into a second color value using color values obtained by the image reading sensor and the colorimeter, corrects the scanner profile according to the color values obtained by the image reading sensor and the colorimeter, and converts the first color value into the second color value using the corrected scanner profile.

First claim

What is claimed is:

1. An image forming apparatus, comprising:
a memory that stores a first color value and a second color value of each patch in a first color chart;
an image forming section comprising a transfer belt and that forms a second color chart on a sheet, wherein the first color chart has more patches than the second color chart;
an image reading sensor a colorimeter that is disposed on a conveyance path of the sheet, reads a sheet surface of the sheet with the second color chart, and outputs a first color value;
a colorimeter that is disposed on the conveyance path of the sheet, reads the sheet surface of the sheet with the second color chart, and outputs a second color value;
a temperature sensor that measures a temperature of the sheet surface read by the image reading sensor and the colorimeter;
a processor that:
creates, based on the first and second color values of the first color chart stored in the memory, a scanner profile for converting the first color value obtained by the image reading sensor into another second color value;
corrects the scanner profile based on the first and second color values that are obtained by the image reading sensor and the colorimeter, respectively; and
converts the first color value obtained by the image reading sensor into the another second color value based on the corrected scanner profile,

wherein the memory further stores a change amount of each of the first and second color values of each patch in the first color chart that changes according to the temperature of the sheet surface,
wherein when the temperature of the sheet surface at a time of reading the first color chart stored in the memory is a first temperature and the temperature of the sheet surface measured by the temperature measuring section at a time of reading the second color chart is a second temperature, the processor corrects the first and second color values of the first color chart stored in the memory using the change amount, and creates the scanner profile using the corrected first and second color values,
wherein the processor corrects the scanner profile, created with the corrected first and second color values, using the first and second color values obtained at the second temperature by the image reading sensor and the colorimeter, respectively, and creates a profile for converting the second color value of the corrected scanner profile into another second color value when the temperature of the sheet surface is at a third temperature using the change amount, and
wherein the processor converts the first color value at the second temperature obtained by the image reading sensor into another second color value at the second temperature, and further converts the converted second color value into a second color value when the temperature of the sheet surface is at the third temperature using the profile.

2. The image forming apparatus according to claim 1 , wherein the third temperature is equal to the first temperature.

3. The image forming apparatus according to claim 1 , wherein the processor excludes the first and second color values obtained by reading each patch in the second color chart from a target of correction.

4. The image forming apparatus according to claim 1 , wherein a reading range of the image reading sensor is an entire sheet surface, and a reading range of the colorimeter is apart of the sheet surface, and the second color chart includes a patch of a basic color used for correcting the scanner profile that is arranged within a common reading range of the image reading sensor and the colorimeter.

5. A non-transitory computer readable recording medium which stores a program for causing a computer to execute a procedure, the procedure comprising:
obtaining, from a memory, a first color value and a second color value of each patch in a first color chart;
forming a second color chart on a sheet using an image forming section with a transfer belt, wherein the first color chart has more patches than the second color chart;
reading a sheet surface of the sheet with the second color chart using an image reading sensor and a colorimeter that are disposed on a conveyance path of the sheet, and outputs a first color value and a second value, respectively;
measuring, using a temperature sensor, a temperature of the sheet surface that is read by the image reading sensor and the colorimeter;
creating, based on the first and second color values of the first color chart stored in the memory, a scanner profile for converting the first color value obtained by the image reading sensor into another second color value;
correcting the scanner profile based on the first and second color values that are obtained by the image reading sensor and the colorimeter, respectively; and
converting the first color value obtained by the image reading sensor into the another second color value based on corrected scanner profile,
wherein the memory further stores a change amount of each of the first and second color values of each patch in the first color chart that change according to the temperature of the sheet surface,
wherein when the temperature of the sheet surface at a time of reading the first color chart stored in the memory is a first temperature and the temperature of the sheet surface measured by the temperature measuring section at a time of reading the second color chart is a second temperature, the processor corrects the first and second color values of the first color chart stored in the memory using the change amount, and creates the scanner profile using the corrected first and second color values,
wherein the processor corrects the scanner profile, created with the corrected first and second color values, using the first and second color values obtained at the second temperature by the image reading sensor and the colorimeter, respectively, and creates a profile for converting the second color value of the corrected scanner profile into another second color value when the temperature of the sheet surface is at a third temperature using the change amount, and
wherein the processor converts the first color value at the second temperature obtained by the image reading sensor into another second color value at the second temperature, and further converts the converted second color value into a second color value when the temperature of the sheet surface is at the third temperature using the profile.

6. The recording medium according to claim 5 , wherein the third temperature is equal to the first temperature.

7. The recording medium according to claim 5 , wherein the processor excludes the first and second color values obtained by reading each patch in the second color chart from a target of correction.

8. The recording medium according to claim 5 , wherein a reading range of the image reading sensor is an entire sheet surface, and a reading range of the colorimeter is a part of the sheet surface, and the second color chart includes a patch of a basic color used for correcting the scanner profile that is arranged within a common reading range of the image reading sensor and the colorimeter.

Assignees

• Konica Minolta Inc

Inventors

• Sakatani Kazuomi

Classifications

• H04N1/6091

  by environmental factors, e.g. temperature or humidity (H04N1/6086, H04N1/6088 take precedence) · CPC title

• H04N1/00023

  Colour systems · CPC title

• G03G15/5062

  by measuring the characteristics of an image on the copy material · CPC title

• H04N1/00013

  Reading apparatus · CPC title

• H04N2201/0005

  using a reference pattern designed for the purpose, e.g. a test chart · CPC title