Image forming apparatus that adjusts relative positions of images by detecting test pattern

Patent metadata

Field	Value
Publication number	US-9846380-B2
Application number	US-201615222246-A
Country	US
Kind code	B2
Filing date	Jul 28, 2016
Priority date	Aug 3, 2015
Publication date	Dec 19, 2017
Grant date	Dec 19, 2017

Abstract

An image forming apparatus includes a detection unit configured to detect a test pattern formed on an image carrier by image forming units; and an adjustment unit configured to control the image forming units to form the test pattern, and adjust relative positions of images based on a detection result of the test pattern. The adjustment unit is further configured to control the image forming units to form the test pattern after the image forming units have formed on the image carrier an image to be transferred to a sheet with a basis weight less than a threshold, and before the image forming units form on the image carrier an image to be transferred to a sheet with a basis weight greater than the threshold.

First claim

What is claimed is:

1. An image forming apparatus, comprising:
a plurality of image forming units configured to form images, each having a different color;
an intermediate transfer member to which the images formed by the plurality of image forming units are transferred, the intermediate transfer member being configured to convey the images;
a detection unit configured to detect a color pattern formed on the intermediate transfer member, the color pattern being used for detecting color misregistration;
a controller configured to:
control the plurality of image forming units to form a first plurality of color patterns, each having a difference color, on the intermediate transfer member,
control the detection unit to detect a first amount of color misregistration, related to a relative position of a color pattern having a reference color among the first plurality of color patterns and a color pattern having another color among the first plurality of color patterns, and
determine a correction value for adjusting an image write start timing of the other color different from the reference color based on the first amount of color misregistration detected by the detection unit; and

an obtaining unit configured to obtain information related to a sheet,
wherein the controller is further configured to, in a case where the plurality of image forming units continuously form a first image and a second image that are to be transferred, respectively, to a first sheet and a second sheet based on a print job, control the plurality of image forming units to form a second plurality of color patterns, each having a different color,
wherein the second plurality of color patterns are formed in between the first image and the second image on the intermediate transfer member,
wherein the controller is further configured to control the detection unit to detect a second amount of color misregistration, related to a relative position of a color pattern having a reference color among the second plurality of color patterns and a color pattern having another color among the second plurality of color patterns, and determine the correction value based on the second amount of color misregistration detected by the detection unit,
wherein a basis weight of the first sheet is less than a predetermined basis weight,
wherein a basis weight of the second sheet is greater than the predetermined basis weight, and
wherein a length of the second plurality of color patterns formed on the intermediate transfer member in a conveyance direction of the images by the intermediate transfer member is longer than a length of the first plurality of color patterns formed on the intermediate transfer member in the conveyance direction.

2. The image forming apparatus according to claim 1 , wherein
the controller is further configured to control the plurality of image forming units to form the first plurality of color patterns in a case where an amount of change in an internal temperature of the image forming apparatus reaches a predetermined amount.

3. The image forming apparatus according to claim 1 , wherein
the controller is further configured to control the plurality of image forming units to form the first plurality of color patterns in a case where a number of printed sheets reaches a predetermined number while the plurality of image forming units are continuously forming images on a plurality of sheets.

4. The image forming apparatus according to claim 1 , wherein
the controller is further configured to control the plurality of image forming units to form the first plurality of color patterns in a case where an elapsed period reaches a predetermined period while the plurality of image forming units are continuously forming images on a plurality of sheets.

5. The image forming apparatus according to claim 1 , wherein
the controller is further configured to control the plurality of image forming units to form the first plurality of color patterns in a case where an elapsed period since power ON of the image forming apparatus reaches a predetermined period.

6. The image forming apparatus according to claim 1 , wherein
the controller is further configured to control the plurality of image forming units to form the first plurality of color patterns in a case where a number of printed sheets since power ON of the image forming apparatus reaches a predetermined number.

7. An image forming apparatus, comprising:
a plurality of image forming units configured to form images, each having a different color;
a transfer member to which the images formed by the plurality of image forming units are transferred;
a detection unit configured to detect a color pattern formed on the transfer member, the color pattern being used for detecting color misregistration; and
a controller configured to:
control the plurality of image forming units to form a plurality of color patterns, each having a difference color, on the transfer member,
control the detection unit to detect an amount of color misregistration, related to a relative position of a color pattern having a reference color among the plurality of color patterns and a color pattern having another color among the plurality of color patterns, and
determine an adjustment value for adjusting an image write start timing of the other color different from the reference color based on the amount of color misregistration detected by the detection unit,

wherein the controller controls the plurality of image forming units to form a first plurality of color patterns while the plurality image forming units continuously forms first images to be transferred onto a first sheet and second images to be transferred onto a second sheet, controls the detection unit to detect a first amount of color misregistration from the first plurality of color patterns, and determines the adjustment value based on the first amount of color misregistration detected by the detection unit,
wherein a basis weight of the first sheet is less than a predetermined basis weight,
wherein a basis weight of the second sheet is less than the predetermined basis weight,
wherein the controller, in a case where the plurality of image forming units continuously form third images to be transferred onto a third sheet and fourth images to be transferred onto a fourth sheet, controls the plurality of image forming units to form a second plurality of color patterns, controls the detection unit to detect a second amount of color misregistration from the second plurality of color patterns, and determines the adjustment value based on the second amount of color misregistration detected by the detection unit,
wherein a basis weight of the third sheet is less than the predetermined basis weight, and
wherein a basis weight of the fourth sheet is greater than the predetermined basis weight.

8. The image forming apparatus according to claim 7 , wherein
the second plurality of color patterns is formed in between the third images and the fourth images on the transfer member.

9. The image forming apparatus according to claim 7 , wherein
the transfer member conveys the images, and
a length of the second plurality of color patterns formed on the transfer member in a conveyance direction of the images by the transfer member is longer than a length of the first plurality of color patterns formed on the transfer member in the conveyance direction.

10. The image forming apparatus according to claim 7 , wherein
the controller controls the plurality of image forming units to form the first plurality of color patterns in a case where an amount of change in an internal temperature of the image forming apparatus reaches a predetermined amount.

Assignees

• Canon Kk

Inventors

• Tajiri Tsuyoshi
• Kishi Takehiro
• Tajima Hirotoshi

Classifications

• G03G15/0131 Primary

  for transferring a pattern to a second base · CPC title

• G03G15/5058

  using a test patch · CPC title

• G03G15/6591

  characterised by the recording material, e.g. plastic material, OHP, ceramics, tiles, textiles (details transferring the toner pattern onto particular materials G03G15/1625) · CPC title

• G03G15/0189

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