# US 10,120,325 B2 · Image forming apparatus

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 10,120,325 B2
- Document ID: US10120325B2
- Status: Granted
- Kind: B2
- Application number: 15/817,401
- Filed: 2017-11-20
- Published: 2018-05-31
- Granted: 2018-11-06
- Earliest claimed: 2016-11-25
- Assignees: Canon Kabushiki Kaisha
- Applicants: Canon Kabushiki Kaisha
- Inventors: Ryo Takaba
- Web page: https://patentgrep.com/patent/US10120325B2

## CPC

- G03G 21/12: Toner waste containers
- G03G 15/095: Removing excess solid developer {, e.g. fog preventing}
- G03G 15/5008: {Driving control for rotary photosensitive medium, e.g. speed control, stop position control}
- G03G 21/10: Collecting or recycling waste developer
- G03G 21/105: {Arrangements for conveying toner waste}
- G03G 15/553: {Monitoring or warning means for exhaustion or lifetime end of consumables, e.g. indication of insufficient copy sheet quantity for a job}
- G03G 15/556: {for toner consumption, e.g. pixel counting, toner coverage detection or toner density measurement}
- G03G 21/169: {for the cleaning unit}
- G03G 2221/0005: Cleaning of residual toner
- G03G 2221/1627: Details concerning the cleaning process
- G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY

## Abstract

An image forming apparatus includes an image bearing member, a charging unit, a developing unit, a transfer unit, a residual developer collecting container, a developer feeding unit, a driving unit configured to drive the developer feeding unit and at least one of the image bearing member, the developing unit and the transfer unit, and a control unit configured to change a driving speed of the driving unit depending on a storing amount of the residual developer in the collecting container in a period from an end of formation of an image on a first recording material to a start of formation of the image on a second recording material subsequent to the first recording material.

## Claims

### Claim 1

An image forming apparatus comprising:
an image bearing member;
a charging unit configured to electrically charge said image bearing member;
a developing unit configured to deposit a developer on a surface of the charged image bearing member;
a transfer unit configured to transfer the developer from said image bearing member onto a recording material;
a collecting container configured to collect a residual developer remaining on the surface of said image bearing member without being transferred onto the recording material;
a developer feeding unit configured to feed, from said collecting container, the residual developer collected in said collecting container;
a driving unit configured to drive said developer feeding unit and at least one of said image bearing member, said developing unit and said transfer unit; and
a control unit configured to change a driving speed of said driving unit depending on a storing amount of the residual developer in said collecting container in a period from an end of formation of an image on a first recording material to a start of formation of the image on a second recording material subsequent to the first recording material.

### Claim 2 (depends on 1)

The image forming apparatus according to claim 1, wherein said control unit drives said driving unit or stops drive of said driving unit depending on the storing amount of the residual developer in said collecting container in the period.

### Claim 3 (depends on 1)

The image forming apparatus according to claim 1, wherein said control unit includes,
an acquiring unit configured to acquire the storing amount of the residual developer in said collecting container, and
a calculating unit configured to calculate a warning amount, of the residual developer, smaller than capacity of said collecting container,
wherein when the storing amount of the residual developer exceeds the warning amount, said control unit drives said driving unit until the storing amount decreases to the warning amount or less.

### Claim 4 (depends on 3)

The image forming apparatus according to claim 3, wherein said calculating unit calculates the warning amount on the basis of the capacity of said collecting container and a collecting amount of the residual developer collected by the formation of the image on the second recording material.

### Claim 5 (depends on 4)

The image forming apparatus according to claim 4, wherein said calculating unit calculates the collecting amount of the residual developer on the basis of a print ratio in the formation of the image on the second recording material.

### Claim 6 (depends on 3)

The image forming apparatus according to claim 3, wherein said control unit calculates a driving time, of said driving unit, necessary to decrease the storing amount of the residual developer to the warning amount or less.

### Claim 7 (depends on 3)

The image forming apparatus according to claim 3, wherein said control unit extends the period until the storing amount decreases to the warning amount or less.

### Claim 8 (depends on 3)

The image forming apparatus according to claim 3, wherein even in a case where the storing amount of the residual developer exceeds the warning amount, said control unit does not change the driving speed of said driving unit in a case where there is no recording material subsequent to the second recording material and the storing amount of the residual developer does not exceed the capacity of said collecting container even when a collecting amount of the residual developer collected by the formation of the image on the second recording material is added to the storing amount.

### Claim 9 (depends on 1)

The image forming apparatus according to claim 1, wherein said control unit includes a predicting unit configured to predict the storing amount from at least one of a print ratio of the developer, a transfer efficiency of the developer onto the recording material and an amount of the residual developer fed by said storing unit.

### Claim 10 (depends on 1)

The image forming apparatus according to claim 1, further comprising a detecting unit configured to detect the storing amount.

### Claim 11 (depends on 1)

The image forming apparatus according to claim 1, wherein said control unit increases the driving speed of said driving unit depending on the storing amount of the residual developer in said collecting container in the period.