Image forming apparatus with forced supply mode for forcedly supplying toner

Patent metadata

Field	Value
Publication number	US-9557683-B2
Application number	US-201514953625-A
Country	US
Kind code	B2
Filing date	Nov 30, 2015
Priority date	Dec 12, 2014
Publication date	Jan 31, 2017
Grant date	Jan 31, 2017

Abstract

An image forming apparatus includes an image bearing member, a developing device, a supplying device, and a controller. The controller can execute a normal supply mode and a forced supply mode on the basis of a difference between a toner supply amount in the normal supply mode and a supply amount of the toner to be supplied to the developing device. In a case where the flag is set when a predetermined time is elapsed after the difference exceeds the predetermined threshold, image formation is effected and then interrupted, and then the controller executes the operation in the forced supply mode, and in a case where the flag is reset when the predetermined time is elapsed after the difference exceeds the predetermined threshold, the image formation is effected and then said controller continues an image forming operation without executing the operation in the forced supply mode.

First claim

What is claimed is:

1. An image forming apparatus comprising:
an image bearing member;
a developing device configured to develop an electrostatic latent image, formed on said image bearing member, with a toner;
a supplying device configured to supply the toner to said developing device; and
a controller configured to control supply of the toner by said supplying device, wherein said controller is further configured for executing an operation in a supply mode and an operation in a forced supply mode, wherein in the supply mode, during a continuous image forming job for forming images on a plurality of recording materials continuously, said supplying device supplies the toner to said developing device without interrupting the image forming job, and wherein in the forced supply mode, during the continuous image forming job, when a toner amount in said developing device reaches a predetermined amount irrespective of supply of the toner in the operation in the supply mode, said supplying device supplies the toner after interrupting the image forming job,
wherein said controller sets a flag for executing the operation in the forced supply mode when the toner amount reaches the predetermined amount during the continuous image forming job, and makes the following determination:
(i) in a case where a state in which the toner amount reaches the predetermined amount is eliminated when the images are formed on a predetermined number of the recording materials after the flag is set, the flag is reset,
(ii) in a case where the state in which the toner amount reaches the predetermined amount is maintained when the images are formed on the predetermined number of the recording materials after the flag is set, said controller executes the operation in the forced supply mode, and
(iii) when the image forming job is ended before the images are formed on the predetermined number of the recording materials after the flag is set, said supplying device supplies the toner after image formation is ended.

2. An image forming apparatus according to claim 1 , wherein the predetermined number is changed depending on a size of the recording materials subjected to the image formation.

3. An image forming apparatus according to claim 1 , further comprising a toner content detecting portion configured to detect a toner content in said developing device,
wherein the supply amount of the toner to be supplied to said developing device is determined on the basis of an amount of the toner consumed every predetermined unit of the image formation, a detection result of said toner content detecting portion and a remaining supply amount of the toner which cannot be supplied in a last supplying operation and which remains in said supplying device.

4. An image forming apparatus according to claim 1 , wherein said controller includes,
a calculating portion configured to calculate the supply amount of the toner to be supplied to said developing device,
wherein in a case where the supply amount of the toner calculated by said calculating portion is not more than a predetermined amount, said controller supplies the toner in the calculated supply amount to said developing device, and in a case where the supply amount of the toner calculated by said calculating portion is more than the predetermined amount, said controller supplies the toner in the predetermined amount to said developing device.

5. An image forming apparatus according to claim 4 , wherein said calculating portion calculates the supply amount of the toner on the basis of a consumption value depending on an amount of the toner consumed every predetermined unit of the image formation.

6. An image forming apparatus according to claim 5 , wherein in said developing device, a developer containing the toner and a carrier,
wherein said image forming apparatus further comprises,
a toner content detecting portion configured to detect a toner content in said developing device, and
a toner content difference calculating portion configured to calculate a toner content difference between a toner content detected by said toner content detecting portion and a target value, and
wherein said calculating portion calculates the supply amount of the toner by adding a value depending on the toner content difference calculated by said toner content difference calculating portion to a value depending on the consumption value.

7. An image forming apparatus according to claim 4 , wherein when the operation in the forced supply mode is not executed, said calculating portion calculates the supply amount of the toner to be supplied to said developing device by adding the difference calculated by said difference calculating portion during subsequent calculation of the supply amount of the toner.

8. An image forming apparatus according to claim 4 , wherein said controller causes said supplying device to supply the toner in an amount depending on the difference calculated by said difference calculating portion immediately before the operation in the forced supply mode is executed.

9. An image forming apparatus according to claim 8 , wherein when the operation in the forced supply mode is executed, said calculating portion calculates the supply amount of the toner to be supplied to said developing device by adding, during subsequent calculation of the supply amount of the toner, a value obtained by subtracting a supply amount of the toner supplied in the operation in the forced supply mode from the difference calculated by said difference calculating portion immediately before the operation in the forced supply mode is executed.

10. An image forming apparatus comprising:
an image bearing member;
a developing device configured to develop an electrostatic latent image, formed on said image bearing member, with a toner;
a supplying device configured to supply the toner to said developing device; and
a controller configured to control supply of the toner by said supplying device, wherein said controller is capable of executing an operation in a supply mode in which during a continuous image forming job for forming images on a plurality of recording materials continuously, said supplying device supplies the toner to said developing device without interrupting the image forming job and an operation in a forced supply mode in which during the continuous image forming job, when a toner amount in said developing device reaches a predetermined amount irrespective of supply of the toner in the operation in the supply mode, said supplying device supplies the toner after interrupting the image forming job;
wherein said controller sets a flag for executing the operation in the forced supply mode when the toner amount reaches the predetermined amount during the continuous image forming job, and makes the following determination:
(i) in a case where a state in which the toner amount reaches the predetermined amount is eliminated when the images are formed in a predetermined period after the flag is set, the flag is reset,
(ii) in a case where the state in which the toner amount reaches the predetermined amount is maintained when the images are formed in the predetermined period after the flag is set, said controller executes the operation in the forced supply mode, and
(iii) when the image forming job is ended before the images are formed in the predetermined period after the flag is set, said supplying device supplies the toner after image formation is ended.

11. An image forming apparatus according to claim 10 , wherein the predetermined period is changed depending on a size of the recording materials subjected to the image formation.

12. An image forming apparatus according to claim 10

Assignees

• Canon Kk

Inventors

• Saito Fumiyoshi
• Nose Katsuya
• Yago Toshihisa
• Mugita Naoki

Classifications

• G03G15/0829 Primary

  Physics · mapped topic

• G03G15/0877

  Arrangements for metering and dispensing developer from a developer cartridge into the development unit · CPC title

• G03G15/0856 Primary

  Detection or control means for the developer level · CPC title

• G03G15/0855

  the concentration being measured by optical means · CPC title

• G03G15/0863

  provided with identifying means or means for storing process- or use parameters, e.g. an electronic memory · CPC title