Image forming apparatus generating conversion condition of measurement unit

Patent metadata

Field	Value
Publication number	US-9729760-B2
Application number	US-201615074910-A
Country	US
Kind code	B2
Filing date	Mar 18, 2016
Priority date	Mar 23, 2015
Publication date	Aug 8, 2017
Grant date	Aug 8, 2017

Abstract

The image forming apparatus including: a controller controlling the image forming unit to form a test image, controlling the measurement unit to measure the test image on the image bearing member, and controlling the transfer unit to transfer the test image to the sheet; a reception unit receiving a user instruction; a second generation unit generating the conversion condition based on the user instruction and the measurement result of the test image, wherein the sample image includes a first sample image, a second sample image, and a third sample image, a color difference between the first and second sample images is smaller than a threshold value, a color difference between the second and third sample images is larger than the threshold value, density of the first sample image is higher than density of the second sample image and density of the third sample image.

First claim

What is claimed is:

1. An image forming apparatus comprising:
an image processor configured to correct image data based on a correction condition;
an image former configured to form an image based on the corrected image data, using developer;
an intermediate transfer member on which the image former forms a measurement image;
a sensor configured to measure the measurement image on the intermediate transfer member;
a converter configured to convert a measurement result of the measurement image by the sensor, based on a conversion condition;
a gamma generator configured to generate the correction condition based on the measurement result converted by the convertor;
a controller configured to control the image former to form a first test image based on test image data, control the sensor to measure the first test image on the intermediate transfer member, and control the image former to form a second test image, based on test image data, on a sheet;
a receptor configured to receive a user instruction based on a result of a user having compared a sample image and the second test image formed on the sheet; and
a conversion condition generator configured to generate the conversion condition based on the user instruction and the measurement result of the first test image by the sensor,
wherein
the sample image includes a plurality of sample images arranged along a predetermined direction,
the plurality of sample images is formed by using a developer of a predetermined color,
the plurality of sample images includes a first sample image, a second sample image, a third sample image and a fourth sample image,
the first sample image and the second sample image are adjacent to each other in the predetermined direction, and
the third sample image and the fourth sample image are adjacent to each other in the predetermined direction,
density of the first sample image is higher than density of the second sample image,
density of the second sample image is higher than density of the third sample image,
density of the third sample image is higher than density of the fourth sample image,
a color difference between the first sample image and the second sample image is smaller than a threshold value, and
a color difference between the third sample image and the fourth sample image is larger than the threshold value.

2. The image forming apparatus according to claim 1 ,
wherein a color difference between the first and second sample images is equal to or larger than 1.6.

3. The image forming apparatus according to claim 1 ,
wherein the threshold value is larger than 3.

4. The image forming apparatus according to claim 1 ,
wherein the sample image includes identification information corresponding to the sample image, and
the user instruction corresponds to the identification information input by the user.

5. The image forming apparatus according to claim 1 ,
wherein the correction condition corresponds to a tone correction table for correcting a tone characteristic of the image data.

6. The image forming apparatus according to claim 1 ,
wherein the second test image is the same as the first test image.

7. An image forming apparatus comprising:
an image processor configured to correct image data based on a correction condition;
an image former configured to form an image based on the corrected image data, using developer;
an intermediate transfer member on which the image former forms the image;
a transfer configured to transfer the image on the intermediate transfer member to a sheet;
a sensor configured to measure the measurement image on the intermediate transfer member;
a converter configured to convert a measurement result of the measurement image by the sensor, based on a conversion condition;
a gamma generator configured to generate the correction condition based on the measurement result converted by the convertor;
a controller configured to control the image former to form a test image, control the sensor to measure the test image on the intermediate transfer member, and control the transfer to transfer the test image formed on the intermediate transfer member to the sheet;
a receptor configured to receive a user instruction based on a result of a user having compared a sample image and the test image transferred on the sheet; and
a conversion condition generator configured to generate the conversion condition based on the user instruction and the measurement result of the test image by the sensor,
wherein
the sample image includes a plurality of sample images arranged along a predetermined direction,
the plurality of sample images is formed by using a developer of a predetermined color,
the plurality of sample images includes a first sample image, a second sample image, a third sample image and a fourth sample image,
the first sample image and the second sample image are adjacent to each other in the predetermined direction,
the third sample image and the fourth sample image are adjacent to each other in the predetermined direction,
density of the first sample image is higher than density of the second sample image,
density of the second sample image is higher than density of the third sample image,
density of the third sample image is higher than density of the fourth sample image,
a color difference between the first sample image and the second sample image is smaller than a threshold value, and
a color difference between the third sample image and the fourth sample image is larger than the threshold value.

8. The image forming apparatus according to claim 7 ,
wherein a color difference between the first and second sample images is equal to or larger than 1.6.

9. The image forming apparatus according to claim 7 ,
wherein the threshold value is larger than 3.

10. The image forming apparatus according to claim 7 ,
wherein the sample image includes identification information corresponding to the sample image, and
the user instruction corresponds to the identification information input by the user.

11. The image forming apparatus according to claim 7 ,
wherein the correction condition corresponds to a tone correction table for correcting a tone characteristic of the image data.

12. The image forming apparatus according to claim 1 , wherein
the second sample image is arranged between the first sample image and the fourth sample image in the predetermined direction, and
the third sample image is arranged between the first sample image and the fourth sample image in the predetermined direction.

13. The image forming apparatus according to claim 7 , wherein
the second sample image is arranged between the first sample image and the fourth sample image in the predetermined direction, and
the third sample image is arranged between the first sample image and the fourth sample image in the predetermined direction.

Assignees

• Canon Kk

Inventors

• Negishi Hayato
• Nakase Takahiro

Classifications

• G03G15/5016

  User-machine interface; Display panels; Control console · CPC title

• H04N1/6008

  with primary colour signals, e.g. RGB or CMY(K) · CPC title

• H04N1/6033 Primary

  using test pattern analysis (H04N1/6055 takes precedence) · CPC title

• H04N1/40087

  Multi-toning, i.e. converting a continuous-tone signal for reproduction with more than two discrete brightnesses or optical densities, e.g. dots of grey and black inks on white paper · CPC title

• G03G15/0189

  primary transfer to an intermediate transfer belt (G03G15/0184 takes precedence) · CPC title