Image forming apparatus and image forming method
AssigneeToshiba Tec Kabushiki Kaisha
InventorKazuhiko Kikuchi
Life of this patent
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Abstract
An image forming apparatus includes a fixing unit including a heater including a heating element, a fixing belt having a surface to which a lubricant is applied and contacting the heater through the lubricant, and a pressing roller capable of pressing and rotating the fixing belt, a power supply configured to supply electric power to the heating element, a first thermometer configured to measure temperature of the heating element, and a controller configured to determine a first amount of electric power to be supplied to the heating element based on the temperature of the heating element, and control the power supply to supply the determined first amount of electric power to the heating element, before controlling the pressing roller to start rotation.
Claims14
An image forming apparatus comprising:
- a fixing unit including:
- a heater including a heating element,
- a fixing belt having a surface to which a lubricant is applied and contacting the heater through the lubricant, and
- a pressing roller capable of pressing and rotating the fixing belt;
- a power supply configured to supply electric power to the heating element;
- a first thermometer configured to measure a temperature of the heating element;
- a second thermometer configured to measure a temperature of the fixing belt;
- and
- a controller configured to determine a first amount of electric power to be supplied to the heating element based on the temperature of the heating element and the temperature of the fixing belt, and control the power supply to supply the determined first amount of electric power to the 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 the heating element is lower than a second predetermined value, and
- a second predetermined amount of electric power that is less than the first predetermined amount of electric power when the temperature of the fixing belt is lower than the first predetermined value and the temperature of the heating element is equal to or higher than the second predetermined value but lower than a third predetermined value.
A method for controlling a fixing unit of an image forming apparatus, the fixing unit including a heater, a fixing belt having a surface to which a lubricant is applied and contacting the heater through the lubricant, and a pressing roller capable of pressing and rotating the fixing belt, the method comprising:
- measuring a temperature of a heating element of the heater;
- measuring a temperature of the fixing belt;
- and
- before rotating the pressing roller, determining a first amount of electric power to be supplied to the heating element based on the temperature of the heating element and the temperature of the fixing belt, and supplying the determined first amount of electric power to the heating element, wherein
- the first amount of electric power is:
- 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 the heating element is lower than a second predetermined value, and
- a second predetermined amount of electric power that is less than the first predetermined amount of electric power when the temperature of the fixing belt is lower than the first predetermined value and the temperature of the heating element is equal to or higher than the second predetermined value but lower than a third predetermined value.
Dependencies are inferred from the claim text.