IP Library › Granted Patent US 11,656,565
Granted Patent B2
US 11,656,565 · App. 17/707,883 · Granted May 23, 2023

Image forming apparatus configured to determine amount of power supplied to heating elements based on measured temperatures

Inventor: Kazuhiko Kikuchi (Yokohama Kanagawa, JP)
Assignee: Toshiba Tec Kabushiki Kaisha
G03G15/2039G03G15/2042
View Patent ↗
Loading inventors, assignments & file history…
Monitor This Case
Get email alerts when status or documents change.
Order Certified Copies
Most orders are placed with the USPTO same day — all within 24 business hours.
Order via The Patent Place →
Pre-filled with this patent's details
Quick Facts
Patent No.
US 11,656,565
App. No.
17/707,883
Granted
May 23, 2023
Kind
B2
Abstract

An image forming apparatus includes a fixing unit including a fixing belt having a surface to which a lubricant is applied, a heater contacting the surface and including heating elements arranged along a width direction of the belt and including first end second end heating elements and a central heating element, and a pressing roller capable of pressing and rotating the belt, a power supply configured to supply power to the heating elements, and a controller configured to determine a first amount of power to be supplied to the central heating element and a second amount of power to be supplied to each end heating element such that the first amount is greater than the second amount, and control the power supply to supply the first and second amounts to the central heating element and each end heating element before controlling the pressing roller to rotate.

Claims (76)

1. An image forming apparatus comprising:

a fixing unit including:

a fixing belt having a surface to which a lubricant is applied,

a heater contacting the surface of the fixing belt and including a plurality of heating elements including first and second heating elements arranged along a width direction of the fixing belt, and

a pressing roller capable of pressing and rotating the fixing belt;

a first thermometer configured to measure a temperature of one of the plurality of heating elements;

a second thermometer configured to measure a temperature of the fixing belt;

a third thermometer configured to measure a temperature outside of the fixing belt;

a power supply configured to supply electric power to the plurality of heating elements; and

a controller configured to:

determine, based on the temperatures measured by the first and second thermometers, a first amount of electric power to be supplied to the first heating element and a second amount of electric power to be supplied to the second heating element such that the first amount of electric power is greater than the second amount of electric power,

correct the first amount of electric power based on the temperature measured by the third thermometer, and

control the power supply to supply the first amount of electric power to the first heating element and the second amount of electric power to the second heating element before controlling the pressing roller to rotate.

2. The image forming apparatus according to claim 1 , wherein

the controller determines, as the first amount of electric power, a first predetermined amount of electric power when the temperature of the fixing belt is lower than a first predetermined value and the temperature of said one of the heating elements is lower than a second predetermined value.

3. The image forming apparatus according to claim 2 , wherein

the controller determines, as the first amount of electric power, a second predetermined amount of electric power when the temperature of the fixing belt is lower than the first predetermined value and the temperature of said one of the heating elements is equal to or higher than the second predetermined value but lower than a third predetermined value, and

the second predetermined amount of electric power is less than the first predetermined amount of electric power.

4. The image forming apparatus according to claim 3 , wherein

the controller determines, as the first amount of electric power, a third predetermined amount of electric power either when the temperature of the fixing belt is equal to or higher than the first predetermined value or when the temperature of the fixing belt is lower than the first predetermined value and the temperature of said one of the heating elements is equal to or greater than the third predetermined value, and

the third predetermined amount of electric power is less than the second predetermined amount of electric power.

5. The image forming apparatus according to claim 1 , wherein

the third thermometer is attached to a housing of the image forming apparatus.

6. The image forming apparatus according to claim 1 , wherein

the controller is configured to determine, based on the temperature of the fixing belt, a third amount of electric power to be supplied to the first heating element when the pressing roller is rotating.

7. The image forming apparatus according to claim 1 , wherein

the first thermometer is configured to measure a temperature of the first heating element.

8. The image forming apparatus according to claim 1 , wherein

the heater further includes a third heating element, and

the first heating element is located between the second and third heating elements.

9. The image forming apparatus according to claim 1 , wherein

a duty ratio of current supplied to the first heating element is greater than a duty ratio of current supplied to the second heating element.

10. An image forming apparatus comprising:

a fixing unit including:

a fixing belt having a surface to which a lubricant is applied,

a heater contacting the surface of the fixing belt and including a plurality of heating elements including first and second heating elements arranged along a width direction of the fixing belt, and

a pressing roller capable of pressing and rotating the fixing belt;

a first thermometer configured to measure a temperature of one of the plurality of heating elements;

a second thermometer configured to measure a temperature of the fixing belt;

a power supply configured to supply electric power to the plurality of heating elements; and

a controller configured to:

determine, based on the temperatures measured by the first and second thermometers, a first amount of electric power to be supplied to the first heating element and a second amount of electric power to be supplied to the second heating element such that the first amount of electric power is greater than the second amount of electric power,

control the power supply to supply the first amount of electric power to the first heating element and the second amount of electric power to the second heating element before controlling the pressing roller to rotate, and

determine, based on the temperature of the fixing belt, a third amount of electric power to be supplied to the first heating element when the pressing roller is rotating.

11. The image forming apparatus according to claim 10 , wherein

the controller determines, as the first amount of electric power, a first predetermined amount of electric power when the temperature of the fixing belt is lower than a first predetermined value and the temperature of said one of the heating elements is lower than a second predetermined value.

12. The image forming apparatus according to claim 11 , wherein

the controller determines, as the first amount of electric power, a second predetermined amount of electric power when the temperature of the fixing belt is lower than the first predetermined value and the temperature of said one of the heating elements is equal to or higher than the second predetermined value but lower than a third predetermined value, and

the second predetermined amount of electric power is less than the first predetermined amount of electric power.

13. The image forming apparatus according to claim 12 , wherein

the controller determines, as the first amount of electric power, a third predetermined amount of electric power either when the temperature of the fixing belt is equal to or higher than the first predetermined value or when the temperature of the fixing belt is lower than the first predetermined value and the temperature of said one of the heating elements is equal to or greater than the third predetermined value, and

the third predetermined amount of electric power is less than the second predetermined amount of electric power.

14. The image forming apparatus according to claim 10 , wherein

the first thermometer is configured to measure a temperature of the first heating element.

15. The image forming apparatus according to claim 10 , wherein

a duty ratio of current supplied to the first heating element is greater than a duty ratio of current supplied to the second heating element.

16. An image forming apparatus comprising:

a fixing unit including:

a fixing belt having a surface to which a lubricant is applied,

a heater contacting the surface of the fixing belt and including a plurality of heating elements including first, second, and third heating elements arranged along a width direction of the fixing belt, the first heating element located between the second and third heating elements, and

a pressing roller capable of pressing and rotating the fixing belt;

a first thermometer configured to measure a temperature of one of the plurality of heating elements;

a second thermometer configured to measure a temperature of the fixing belt;

a power supply configured to supply electric power to the plurality of heating elements; and

a controller configured to:

determine, based on the temperatures measured by the first and second thermometers, a first amount of electric power to be supplied to the first heating element and a second amount of electric power to be supplied to the second heating element such that the first amount of electric power is greater than the second amount of electric power, and

control the power supply to supply the first amount of electric power to the first heating element and the second amount of electric power to the second heating element before controlling the pressing roller to rotate, wherein

the controller determines, as the first amount of electric power, a first predetermined amount of electric power when the temperature of the fixing belt is lower than a first predetermined value and the temperature of said one of the heating elements is lower than a second predetermined value.

17. The image forming apparatus according to claim 16 , wherein

the controller determines, as the first amount of electric power, a second predetermined amount of electric power when the temperature of the fixing belt is lower than the first predetermined value and the temperature of said one of the heating elements is equal to or higher than the second predetermined value but lower than a third predetermined value, and

the second predetermined amount of electric power is less than the first predetermined amount of electric power.

18. The image forming apparatus according to claim 17 , wherein

the controller determines, as the first amount of electric power, a third predetermined amount of electric power either when the temperature of the fixing belt is equal to or higher than the first predetermined value or when the temperature of the fixing belt is lower than the first predetermined value and the temperature of said one of the heating elements is equal to or greater than the third predetermined value, and

the third predetermined amount of electric power is less than the second predetermined amount of electric power.

19. The image forming apparatus according to claim 16 , wherein

the first thermometer is configured to measure a temperature of the first heating element.

Priority Claims (1)
JP JP2019-021851 · Feb 8, 2019 · national
Continuity (3)
Continuation 17152718 · Jan 19, 2021
Continuation 16728691 · Dec 27, 2019
Related Publication 20220221813A1 · Jul 14, 2022