Method of controlling target speed of rotating member used in image forming apparatus

Patent metadata

Field	Value
Publication number	US-10146163-B2
Application number	US-201715627976-A
Country	US
Kind code	B2
Filing date	Jun 20, 2017
Priority date	Jul 12, 2016
Publication date	Dec 4, 2018
Grant date	Dec 4, 2018

Abstract

When a mechanism enters a first state, an intermediate transfer member separates from a second photosensitive member. When the mechanism enters a second state, the intermediate transfer member contacts the second photosensitive member. When a first monochrome image is formed on a sheet of a first type by using toner of a first color, the mechanism enters the first state. When a second monochrome image is formed on a sheet of a second type by using toner of the first color, the mechanism enters the second state. A rotation speed of the second photosensitive member for forming the second monochrome image on the sheet of the second type is controlled to a predetermined rotation speed. The predetermined rotation speed is slower than a rotation speed of the second photosensitive member for forming the second image.

First claim

What is claimed is:

1. An image forming apparatus having an intermediate transfer member that transfers an image on the intermediate transfer member to a sheet, the apparatus comprising:
a first image forming unit configured to use toner of a first color to form a first image on a first photosensitive member;
a second image forming unit configured to use toner of a second color that is different from the first color to form a second image on a second photosensitive member;
a driving control unit configured to control a rotation speed of the second photosensitive member;
a first transferring member configured to form a first transferring nip portion for transferring the first image formed on the first photosensitive member to the intermediate transfer member;
a second transferring member configured to form a second transferring nip portion for transferring the second image formed on the second photosensitive member to the intermediate transfer member; and
a controller configured to control a mechanism for causing contact and separation of the second photosensitive member and the intermediate transfer member,
wherein, in a case where the mechanism is controlled to enter a first state, the intermediate transfer member separates from the second photosensitive member,
wherein, in a case where the mechanism is controlled to enter a second state, the intermediate transfer member contacts the second photosensitive member,
wherein in a case where a first monochrome image is formed on a sheet of a first type by using the toner of the first color, the controller controls the mechanism to enter the first state,
wherein in a case where a second monochrome image is formed on a sheet of a second type that is different from the first type by using the toner of the first color, the controller controls the mechanism to enter the second state,
wherein the driving control unit controls a rotation speed of the second photosensitive member for forming the second monochrome image on the sheet of the second type to a predetermined rotation speed, and
wherein the predetermined rotation speed is slower than a rotation speed of the second photosensitive member for forming the second image.

2. The image forming apparatus according to claim 1 , wherein
a grammage of the sheet of the first type is less than or equal to a predetermined value, and
a grammage of the sheet of the second type is greater than the predetermined value.

3. The image forming apparatus according to claim 2 , wherein
the controller obtains information relating to the grammage of a sheet, and
the controller controls the mechanism based on the information.

4. The image forming apparatus according to claim 1 , wherein
the intermediate transfer member rotates based on a target rotation speed, and
a circumferential speed difference between the second photosensitive member and the intermediate transfer member in a state where the second photosensitive member is rotating based on the predetermined rotation speed is less than a circumferential speed difference between the second photosensitive member and the intermediate transfer member for forming the second image.

5. The image forming apparatus according to claim 1 , further comprising:
a first sensor configured to detect a rotation speed of the first photosensitive member; and
a second sensor configured to detect a rotation speed of the second photosensitive member,
wherein the rotation speed of the first photosensitive member is subject to feedback control based on a detection result by the first sensor, and
the rotation speed of the second photosensitive member is subject to feedback control based on a detection result by the second sensor.

6. The image forming apparatus according to claim 1 , wherein
the intermediate transfer member rotates based on a target rotation speed, and
a circumferential speed of the first photosensitive member for forming the first image is faster than a circumferential speed of the intermediate transfer member.

7. The image forming apparatus according to claim 1 , wherein
the intermediate transfer member rotates based on a target rotation speed, and
a circumferential speed of the first photosensitive member for forming the first image is slower than a circumferential speed of the intermediate transfer member.

8. The image forming apparatus according to claim 1 , further comprising:
a motor configured to rotate the intermediate transfer member; and
a sensor configured to detect a rotation speed of the intermediate transfer member,
wherein the driving control unit executes feedback control based on a detection result of the sensor to control a rotation speed of the motor, and
the driving control unit controls, based on a load torque of the motor, whether to change the rotation speed of the second photosensitive member while a plurality of second monochrome images are formed on a plurality of sheets of the second type.

9. The image forming apparatus according to claim 8 , wherein
the driving control unit controls whether to change the rotation speed of the second photosensitive member based on a load torque of a period in which the plurality of the second monochrome image are formed on the plurality of sheets of the second type.

10. The image forming apparatus according to claim 9 , wherein
the driving control unit controls whether to change the rotation speed of the second photosensitive member based on a load torque of a predetermined period included in the period, and
the predetermined period is a period in which a sleeve for supplying toner to the first photosensitive member has stopped rotation.

11. The image forming apparatus according to claim 1 , further comprising:
a motor configured to rotate the intermediate transfer member; and
a sensor configured to detect a rotation speed of the intermediate transfer member,
wherein the driving control unit executes feedback control based on a detection result of the sensor to control a rotation speed of the motor, and
the driving control unit controls, based on power supplied to the motor, whether to change the rotation speed of the second photosensitive member in a case where the second monochrome image is formed on the sheet of the second type.

12. The image forming apparatus according to claim 11 , wherein
the driving control unit controls whether to change the rotation speed of the second photosensitive member based on the power in a period in which a plurality of second monochrome images are formed on a plurality of sheets of the second type.

13. The image forming apparatus according to claim 12 , wherein
the driving control unit controls whether to change the rotation speed of the second photosensitive member based on the power of a predetermined period included in the period, and
the predetermined period is a period in which a sleeve for supplying toner to the first photosensitive member has stopped rotation.

14. The image forming apparatus according to claim 13 , wherein
the driving control unit lowers the rotation speed of the second photosensitive member if the power of the predetermined period is less than a threshold.

15. The image forming apparatus according to claim 11 , further comprising:
a detection unit for detecting a test image, used in color registration, that is formed on the intermediate transfer member,
wherein the first image forming unit and the second image forming unit form a test image before a mixed-color image is formed if the driving control unit has changed the rotation speed of the second photosensitive member.

16. The image fo

Assignees

• Canon Kk

Inventors

• Ishikawa Rin
• Iwakawa Tadashi
• Taniguchi Koichi
• Hamano Akira

Classifications

• G03G15/0189

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

• G03G15/757

  Drive mechanisms for photosensitive medium, e.g. gears · CPC title

• G03G15/0163

  primary transfer to the final recording medium · CPC title

• G03G15/5008 Primary

  Driving control for rotary photosensitive medium, e.g. speed control, stop position control · CPC title

• G03G15/0136

  transfer member separable from recording member or vice versa, mode switching · CPC title