Image forming apparatus having a cooling portion and a controller configured to operate the cooling portion in one mode of a plurality of modes

Patent metadata

Field	Value
Publication number	US-10775720-B2
Application number	US-201916363251-A
Country	US
Kind code	B2
Filing date	Mar 25, 2019
Priority date	Mar 26, 2018
Publication date	Sep 15, 2020
Grant date	Sep 15, 2020

Abstract

An image forming apparatus including an image forming portion, a heating portion, a discharging portion, a cooling portion, and a controller. A toner amount per predetermined sheet area of a toner image formed on a sheet is a toner image density. A first toner image does not have regions where the toner image density is a predetermined first density or more, and when the first toner image is formed on the sheet, the controller executes an operation in a first mode. A second toner image includes the region, and when the second toner image is formed on the sheet, the controller executes an operation in a second mode higher in cooling power than the first mode irrespective of a toner amount of the second toner image over entirety of the sheet.

First claim

What is claimed is:

1. An image forming apparatus comprising:
an image forming portion configured to form a toner image on a sheet;
a heating portion configured to heat the toner image formed by said image forming portion as the sheet is passed through said heating portion;
a discharging portion configured to discharge the sheet passed through said heating portion;
a cooling portion configured to cool the sheet heated by said heating portion;
an acquiring portion configured to acquire information on the toner image formed on the sheet; and
a controller capable of causing said cooling portion to operate in any one of a plurality of modes, the plurality of modes including a first mode and a second mode that is higher in cooling power than the first mode, the controller being configured to control said cooling portion on the basis of the information acquired by said acquiring portion such that,
(i) when a first toner image is formed on the sheet, said controller operates said cooling portion in the first mode, in the first toner image, a region where a toner image density having a predetermined first density or more is absent, and
(ii) when a second toner image, in which the region is present, is formed on the sheet, said controller operates said cooling portion in the second mode irrespective of a toner amount of the second toner image over the entirety of the sheet,

wherein the toner image density is a toner amount per predetermined sheet area of the toner image formed on the sheet by said image forming portion.

2. The image forming apparatus according to claim 1 , wherein the entirety of a region in which said image forming portion is capable of forming the toner image on the sheet is constituted by a plurality of unit regions each having a predetermined sheet area, and
wherein said acquiring portion acquires information on the toner image density in each of the unit regions from image data corresponding to the toner image to be formed on the sheet by said image forming portion, and said controller is configured to execute the operation in the first mode when said controller determines that the toner image density in each of the unit regions of all the unit regions is lower than the first density and executes the operation in the second mode when the controller discriminates that the toner image density in any one of the unit regions is the first density or more.

3. The image forming apparatus according to claim 1 , wherein the plurality of modes includes a third mode that is higher in cooling power than the second mode, and
wherein, in a case when the toner image to be formed on the sheet by said image forming portion includes the region where the toner image density is the first density or more, said controller operates said cooling portion in the third mode when a region where the toner image density having a second density that is higher than the first density is present and operates said cooling portion in the second mode when the region where the toner image density having the second density or more is absent.

4. The image forming apparatus according to claim 1 , wherein, in a case when the region, where the toner image density is the first density or more is present in the toner image to be formed on the sheet by the image forming apparatus, said controller is configured to change the cooling power of said cooling portion depending on an area of each region of all of the regions where the toner image density is the first density or more.

5. The image forming apparatus according to claim 1 , further comprising a temperature detecting portion configured to detect a temperature,
wherein when the temperature detected by said temperature detecting portion is a predetermined temperature or more, said controller is configured to cause said cooling portion to operate in the first mode or the second mode, depending on whether or not the region where the toner image density is the first density is present, and
wherein, when the temperature detected by said detecting portion is less than the predetermined temperature, said controller is configured to cause said cooling portion to operate in a mode lower in cooling power than the first mode.

6. The image forming apparatus according to claim 1 , wherein said cooling portion is a fan for blowing air on the sheet passed through said heating portion, the fan blowing air in an air blowing amount, and wherein the air blowing amount in the first mode is set at a value that is less than an air blowing amount in the second mode.

7. The image forming apparatus according to claim 1 , wherein, in a case when toner images are formed on a plurality of sheets by said image forming portion, said controller determines, depending on the toner image formed on each of the sheets, an operation mode of said cooling portion when each of the sheets is discharged by said discharging portion.

8. The image forming apparatus according to claim 1 , further comprising a stacking portion configured to stack the sheets discharged by said discharging portion,
wherein said cooling portion cools the sheet in a sheet feeding path between said heating portion and said discharging portion.

9. An image forming apparatus comprising:
an image forming portion configured to form a toner image on a sheet;
a heating portion configured to heat the toner image formed by said image forming portion as the sheet is passed through said heating portion;
a discharging portion configured to discharge the sheet passed through said heating portion;
a cooling portion configured to cool the sheet heated by said heating portion;
an acquiring portion configured to acquire information on the toner image formed on the sheet; and
a controller configured to control said cooling portion on the basis of the information acquired by said acquiring portion,
wherein said controller is configured to control said cooling portion in a first mode when a first sheet on which a first toner image is formed, is cooled by said cooling portion, and to control said cooling portion in a second mode that is greater in cooling power than the first mode when a second sheet, on which a second toner image is formed, is cooled by said cooling portion,
wherein an entire toner amount of the first toner image is more than an entire toner amount of the second toner image,
wherein, in the first toner image, a region where the toner image density having a first density or more is absent, and
wherein, in the second toner image, a region where the toner image density having the first density or more is present.

10. The image forming apparatus according to claim 9 , further comprising a fan, wherein a rotational speed of said fan in the second mode is higher than a rotational speed of said fan in the first mode.

Assignees

• Canon Kk

Inventors

• Suzuki Koji

Classifications

• G03G15/5025

  by measuring the original characteristics, e.g. contrast, density · CPC title

• G03G21/206

  Conducting air through the machine, e.g. for cooling, filtering, removing gases like ozone · CPC title

• G03G15/5062 Primary

  by measuring the characteristics of an image on the copy material · CPC title

• G03G15/2017 Primary

  Structural details of the fixing unit in general, e.g. cooling means, heat shielding means (G03G15/2053 takes precedence) · CPC title