Image forming apparatus

Patent metadata

Field	Value
Publication number	US-2019011877-A1
Application number	US-201816029986-A
Country	US
Kind code	A1
Filing date	Jul 9, 2018
Priority date	Jul 10, 2017
Publication date	Jan 10, 2019
Grant date	—

Abstract

An image forming apparatus includes an image bearing member; a developing device including a developer container, a feeding member, and a developer carrying member; a toner supplying portion including a feeding screw, and a controller; and a supply rotation number determining portion. The controller controls the driving portion so that the feeding screw is rotated at a first rotational speed when the supply rotation number determining portion determines a number of times of the rotation at a first integer of times of rotation and so that the feeding screw is rotated at a second rotational speed slower than the first rotational speed when the supply rotation number determining portion determines the number of times of the rotation at a second integer of times of rotation smaller than the first integer of times of rotation.

First claim

What is claimed is:

1 . An image forming apparatus comprising:
an image bearing member; a developing device including a developer container accommodating a developer containing toner and a carrier, a feeding member configured to feed the developer, and a developer carrying member configured to carry and feed the developer; a toner supplying portion including a feeding screw configured to feed the toner to be supplied to said developing device, a driving source configured to rotationally drive said feeding screw, and a controller configured to control drive of said feeding screw, wherein in said toner supplying portion, a first integer of times of rotation of said feeding screw in a predetermined period is a maximum integer and is set in advance, and wherein an amount of the toner to be supplied to said developing device is controlled by an integer of times of rotation of said feeding screw in the predetermined period; and a supply rotation number determining portion configured to determine a number of times of rotation of said feeding screw for supplying the toner to said developing device, depending on an image signal, wherein said controller controls said driving portion so that said feeding screw is rotated at a first rotational speed when said supply rotation number determining portion determines the number of times of the rotation at the first integer of times of rotation and so that said feeding screw is rotated at a second rotational speed slower than the first rotational speed when said supply rotation number determining portion determines the number of times of the rotation at a second integer of times of rotation smaller than the first integer of times of rotation.

2 . An image forming apparatus according to claim 1 , wherein the number of times of rotation of said feeding screw determined by said supply rotation number determining portion is an integer.

3 . An image forming apparatus according to claim 1 , wherein said predetermined period corresponds to a time in which an image with an A4-size width is formed.

4 . An image forming apparatus according to claim 1 , further comprising a temperature detecting portion configured to measure a temperature of said developing device or a temperature in the neighborhood of said developing device,
wherein the rotational speed of said feeding screw is changed depending on temperature information detected by said temperature detecting portion.

5 . An image forming apparatus according to claim 4 , wherein the rotational speed of said feeding screw is decreased when the temperature detected by said temperature detecting portion is higher than a predetermined temperature.

6 . An image forming apparatus according to claim 1 , wherein the second rotational speed is set so that rotation of said feeding screw is ended in the predetermined period.

7 . An image forming apparatus according to claim 1 , further comprising,
a portion-to-be-detected provided in said feeding screw and configured to detect a rotational phase of said feeding screw, and a detecting portion configured to detect said portion-to-be-detected.

8 . An image forming apparatus according to claim 1 , wherein said driving source is a DC motor.

9 . An image forming apparatus comprising:
an image bearing member;
a developing device including a developer container accommodating a developer containing toner and a carrier, a feeding member configured to feed the developer, and a developer carrying member configured to carry and feed the developer;
a toner supplying portion including a feeding screw configured to feed the toner to be supplied to said developing device, a driving source configured to rotationally drive said feeding screw, and a controller configured to control drive of said feeding screw, wherein in said toner supplying portion, a first integer of times of rotation of said feeding screw in a predetermined period is a maximum integer and is set in advance, and wherein an amount of the toner to be supplied to said developing device is controlled by an integer of times of rotation of said feeding screw in the predetermined period; and
a supply rotation number determining portion configured to determine a number of times of rotation of said feeding screw for supplying the toner to said developing device, depending on an image signal,
wherein said controller effects controls so that the toner is supplied to said developing device by rotating said feeding screw at a first rotational speed when an image with a first roller is continuously formed and so that the toner is supplied to said developing device by rotating said feeding screw at a second rotational speed slower than the first rotational speed when an image with a second image ratio smaller than the first image ratio and smaller than a predetermined value is continuously formed.

10 . An image forming apparatus according to claim 9 , wherein the first image ratio is 84% or more

11 . An image forming apparatus according to claim 9 , wherein the second image ratio is 7% or less.

12 . An image forming apparatus according to claim 9 , wherein the number of times of rotation of said feeding screw determined by said supply rotation number determining portion is an integer.

13 . An image forming apparatus according to claim 9 , wherein said predetermined period corresponds to a time in which an image with an A4-size width is formed.

14 . An image forming apparatus according to claim 9 , further comprising a temperature detecting portion configured to measure a temperature of said developing device or a temperature in the neighborhood of said developing device,
wherein the rotational speed of said feeding screw is changed depending on temperature information detected by said temperature detecting portion.

15 . An image forming apparatus according to claim 14 , wherein the rotational speed of said feeding screw is decreased when the temperature detected by said temperature detecting portion is higher than a predetermined temperature.

16 . An image forming apparatus according to claim 9 , wherein the second rotational speed is set so that rotation of said feeding screw is ended in the predetermined period.

17 . An image forming apparatus according to claim 9 , further comprising,
a portion-to-be-detected provided in said feeding screw and configured to detect a rotational phase of said feeding screw, and a detecting portion configured to detect said portion-to-be-detected.

18 . An image forming apparatus according to claim 9 , wherein said driving source is a DC motor.

Assignees

• Canon Kk

Inventors

• Takahashi Kyosuke
• Fujita Hideki
• Noguchi Akihiro
• Furukawa Mitsuhiro
• Takeuchi Kosuke

Classifications

• G03G15/087 Primary

  Developer cartridges having a longitudinal rotational axis, around which at least one part is rotated when mounting or using the cartridge · CPC title

• G03G21/20 Primary

  Humidity or temperature control {also ozone evacuation; Internal apparatus environment control} · CPC title

• G03G15/0887

  Arrangements for conveying and conditioning developer in the developing unit, e.g. agitating, removing impurities or humidity · CPC title

• G03G15/0893

  in a closed loop within the sump of the developing device · CPC title