Image forming apparatus

Patent metadata

Field	Value
Publication number	US-9354577-B2
Application number	US-201514630883-A
Country	US
Kind code	B2
Filing date	Feb 25, 2015
Priority date	Feb 28, 2014
Publication date	May 31, 2016
Grant date	May 31, 2016

Abstract

A controller for an image forming apparatus includes a difference calculating portion for calculating a difference between a consumption value depending on an amount of the toner consumed every predetermined unit and a reference value; and a difference integrating portion. When an integrated value of the difference is larger than a predetermined threshold, the controller executes an operation in a forced consumption mode so that the toner is consumed in an amount corresponding to a predetermined value obtained by multiplying the predetermined threshold by a coefficient of less than 1. When the operation is executed, the integrating portion sets, at a reset value, a value obtained by subtracting the predetermined value from the integrated value at that time. After the operation is executed, the controller executes the operation every time when an integrated value obtained by integrating the reset value and the difference is larger than the predetermined threshold.

First claim

What is claimed is:

1. An image forming apparatus comprising:
an image bearing member;
a developing device for developing an electrostatic latent image, formed on said image bearing member, with a toner;
a supplying device for supplying the toner to said developing device depending on a consumption amount of a developer; and
a controller capable of executing an operation in a forced consumption mode in which the toner is forcedly consumed by said developing device, wherein said controller includes:
a difference calculating portion for calculating a difference between a consumption value depending on an amount of the toner consumed every predetermined unit of image formation and a reference value set for the predetermined unit; and
an integrating portion for integrating the difference to obtain an integrated value,
wherein when the integrated value is larger than a predetermined threshold, said controller executes the operation in the forced consumption mode so that the toner is consumed in an amount corresponding to a value obtained by multiplying the predetermined threshold by a coefficient of less than 1,
wherein when the operation in the forced consumption mode is executed, said integrating portion sets, at a reset value, a value obtained by subtracting the value, obtained by multiplying the predetermined threshold by the coefficient, from the integrated value at the time when the operation is executed, and
wherein after the operation in the forced consumption mode is executed, said controller executes the operation in the forced consumption mode every time when an integrated value obtained by integrating the reset value and the difference is larger than the predetermined threshold.

2. An image forming apparatus according to claim 1 , wherein said integrating portion integrates the difference from zero when use of said developing device is started from an unused state.

3. An image forming apparatus according to claim 1 , wherein said difference calculating portion calculates the difference by subtracting the consumption value from the reference value, and
wherein said controller resets the integrated value by said integrating portion to zero when the integrated value of the difference by said integrating portion is a negative value.

4. An image forming apparatus according to claim 1 , wherein when the integrated value is not less than the predetermined threshold, said controller causes said integrating portion to integrate the integrated value at that time and the difference after that time without executing the operation in the forced consumption mode.

5. An image forming apparatus according to claim 1 , further comprising an image ratio calculating portion for calculating an average image ratio which is an image ratio per the predetermined unit with respect to a predetermined number of sheets subjected to image formation, where the average image ratio includes a first ratio and a second ratio smaller than the first ratio,
wherein said controller makes the coefficient larger when the average image ratio is the second ratio than when the average image ratio is the first ratio.

6. An image forming apparatus according to claim 1 , further comprising a driving time calculating portion for calculating a driving time of said developing device every image formation of one sheet,
wherein said controller changes the reference value depending on the driving time.

7. An image forming apparatus according to claim 1 , wherein when images each having the same image ratio are continuously formed, said controller executes the operation in the forced consumption mode so that the number of sheets subjected to image formation from a time when the integrated value by the integrating portion is zero until the operation in the forced consumption mode is first executed is larger than the number of sheets subjected to image formation from the execution of the forced consumption mode until a subsequent operation in the forced consumption mode is executed.

8. An image forming apparatus according to claim 1 , wherein said controller includes said integrating portion for integrating a value relating to the amount of the toner consumed every predetermined unit of image formation, and resets the value integrated by said integrating portion when the value integrated by said integrating portion satisfies a predetermined reset condition by formation of an image having a high image ratio,
wherein the predetermined reset condition is such that the value integrated by said integrating portion is reset.

9. An image forming apparatus according to claim 1 , wherein said controller executes the operation in the forced consumption mode when the value integrated by said integrating portion is larger than the predetermined threshold.

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 execute an operation in a forced consumption mode in which the toner is forcedly consumed by transferring the toner from said developing device onto a region of said image bearing member corresponding to an interval between a recording material and a subsequent recording material in an image forming job for continuously outputting images on a plurality of recording materials,
wherein when said developing device is first used and a first image forming job for continuously outputting only such an image that an image ratio corresponds to a predetermined ratio or less is executed, the number of recording materials subjected to image formation until the operation in the forced consumption mode is first executed during the first image forming job is a first number of recording materials subjected to image formation, and
when said developing device is subjected to at least one operation in the forced consumption mode from an unused state and thereafter a second image forming job is executed immediately after execution of the last operation in the forced consumption mode under the same condition as a condition for the first image forming job, the number of recording materials subjected to image formation until the operation in the forced consumption mode is first executed during the second image forming job is a second number of recording materials subjected to image formation,
the first number is larger than the second number.

11. 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 execute an operation in a forced consumption mode in which the toner is forcedly consumed by transferring the toner from said developing device onto a region of said image bearing member corresponding to an interval between a recording material and a subsequent recording material in an image forming job for continuously outputting images on a plurality of recording materials,
wherein when said developing device is first used and a first image forming job for continuously outputting only such an image that information on an amount of the toner consumed per unit driving time of said developing device is less than a predetermined value is executed, the number of recording materials subjected to image formation until the operation in the forced consumption mode is first executed during the first image forming job is a first number of recording materials subjected to image formation, an

Assignees

• Canon Kk

Inventors

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

Classifications

• G03G15/556 Primary

  for toner consumption, e.g. pixel counting, toner coverage detection or toner density measurement · CPC title

• G03G15/553 Primary

  Monitoring or warning means for exhaustion or lifetime end of consumables, e.g. indication of insufficient copy sheet quantity for a job · CPC title

• G03G15/50 Primary

  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 title