IMAGE FORMING APPARATUS

• US 20180107143A1
• Filed: 10/11/2017
• Published: 04/19/2018
• Est. Priority Date: 10/19/2016
• Status: Active Application

• Current Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Original Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Inventors: Shigehiro, Koji, Terada, Ryohei
• Granted Patent: US 10,274,880 B2
• Time in Patent Office: Days
• CPC Class Codes: G03G 15/0806 on a donor element, e.g. belt, roller complete developer unit G03G15/0896
• CPC Class Codes: G03G 15/0865 Arrangements for supplying new developer
• CPC Class Codes: G03G 15/0893 in a closed loop within the sump of the developing device
• CPC Class Codes: G03G 15/0921 Details concerning the magnetic brush roller structure, e.g. magnet configuration
• CPC Class Codes: G03G 15/50 Machine control of apparatus for electrographic processes using a charge pattern, e.g. regulating differents parts of the machine, multimode copiers, microprocessor control sequencing control G03G21/14
• CPC Class Codes: G03G 21/203 Humidity
• CPC Class Codes: G03G 2221/1657 transmitting mechanical drive power

Abstract

Provided is an image forming apparatus, including: a developer containing unit configured to contain developer; a developer bearing member, which is rotatably provided in the developer containing unit, and is configured to bear the developer; a driving unit configured to drive the developer bearing member; and a control unit configured to control the driving unit so that, when rotation of the developer bearing member is stopped after an image forming operation is terminated, drive transmission to the developer bearing member is turned off after a rotational speed of the developer bearing member is reduced to a set rotational speed lower than a rotational speed of the developer bearing member during the image formation while performing the drive transmission to the developer bearing member.

Claims

1. An image forming apparatus, comprising:

a developer containing unit configured to contain developer;

a developer bearing member, which is rotatably provided in the developer containing unit, and is configured to bear the developer;

a driving unit configured to drive the developer bearing member; and

a control unit configured to control the driving unit so that, when rotation of the developer bearing member is stopped after an image forming operation is terminated, drive transmission to the developer bearing member is turned off after a rotational speed of the developer bearing member is reduced to a set rotational speed lower than a rotational speed of the developer bearing member during the image formation while performing the drive transmission to the developer bearing member.

2. An image forming apparatus according to claim 1, wherein, when the rotational speed of the developer bearing member during the image formation is lower than a predetermined rotational speed, and the rotation of the developer bearing member is stopped after the image forming operation is terminated, the control unit turns off the drive transmission to the developer bearing member.

3. An image forming apparatus according to claim 1, wherein a deceleration amount per unit time from the rotational speed of the developer bearing member during the image formation to the set rotational speed is smaller than a deceleration amount per unit time from the set rotational speed to the stop of the rotation of the developer bearing member.

4. An image forming apparatus according to claim 1,

wherein the driving unit comprises a motor, and

wherein the control unit is configured to turn off drive of the motor after reducing the rotational speed of the developer bearing member to the set rotational speed.

5. An image forming apparatus according to claim 1, further comprising a density detecting unit configured to detect a density of the developer contained in the developer containing unit,

wherein the control unit is configured to change a deceleration amount per unit time from the rotational speed of the developer bearing member during the image formation to the set rotational speed in accordance with a detection result given by the density detecting unit.

6. An image forming apparatus according to claim 5, wherein the control unit is configured to set the deceleration amount in a case in which the density is at a second density higher than a first density to be smaller than the deceleration amount in a case in which the density is at the first density.

7. An image forming apparatus according to claim 1, further comprising a density detecting unit configured to detect a density of the developer contained in the developer containing unit,

wherein the control unit is configured to change the set rotational speed in accordance with a detection result given by the density detecting unit.

8. An image forming apparatus according to claim 7, wherein the control unit is configured to set the set rotational speed in a case in which the density is at a second density higher than a first density to be smaller than the set rotational speed in a case in which the density is at the first density.

9. An image forming apparatus according to claim 1, further comprising an environment detecting unit configured to detect an environment of an atmosphere in the developer containing unit,

wherein the control unit is configured to change a deceleration amount per unit time from the rotational speed of the developer bearing member during the image formation to the set rotational speed in accordance with a detection result given by the environment detecting unit.

10. An image forming apparatus according to claim 9,

wherein the control unit is configured to change the deceleration amount in accordance with one of temperature and humidity of the environment, and

wherein the control unit is configured to set one of the deceleration amount to be lower than the deceleration amount in a case in which the temperature is at a first temperature when the temperature is at a second temperature higher than the first temperature, and the deceleration amount to be lower than the deceleration amount in a case in which the humidity is at a first humidity when the humidity is at a second humidity higher than the first humidity.

11. An image forming apparatus according to claim 1, further comprising an environment detecting unit configured to detect an environment of an atmosphere of the developer contained in the developer containing unit,

wherein the control unit is configured to change the set rotational speed in accordance with a detection result given by the environment detecting unit.

12. An image forming apparatus according to claim 11,

wherein the control unit is configured to change the set rotational speed in accordance with one of temperature and humidity of the environment, and

wherein the control unit is configured to set one of the set rotational speed to be lower than the set rotational speed in a case in which the temperature is at a first temperature when the temperature is at a second temperature higher than the first temperature, and the set rotational speed to be lower than the set rotational speed in a case in which the humidity is at a first humidity when the humidity is at a second humidity higher than the first humidity.

13. An image forming apparatus according to claim 1, further comprising a processing unit configured to obtain a printing rate of an output image,

wherein the control unit is configured to change a deceleration amount per unit time from the rotational speed of the developer bearing member during the image formation to the set rotational speed in accordance with the printing rate obtained by the processing unit.

14. An image forming apparatus according to claim 13, wherein the control unit is configured to set the deceleration amount in a case in which the printing rate is at a second printing rate higher than a first printing rate to be smaller than the deceleration amount in a case in which the printing rate is at the first printing rate.

15. An image forming apparatus according to claim 1, further comprising a processing unit configured to obtain a printing rate of an output image,

wherein the control unit is configured to change the set rotational speed in accordance with the printing rate obtained by the processing unit.

16. An image forming apparatus according to claim 15, wherein the control unit is configured to set the set rotational speed in a case in which the printing rate is at a second printing rate higher than a first printing rate to be smaller than the set rotational speed in a case in which the printing rate is at the first printing rate.

17. An image forming apparatus according to claim 1, wherein the developer contained in the developer containing unit comprises two-component developer including toner and carrier.