IMAGE FORMING APPARATUS AND METHOD
First Claim
1. An image forming apparatus comprising:
- a print process part configured to form a not yet fixed developer image on a sheet;
a heat roller configured to include a heating element, generate heat to the developer image on the sheet from the print process part and raise a first roller temperature by the heating element from a reference temperature to a first specified temperature;
a press roller configured to press the sheet in cooperation with the heat roller, include a heater, and raise a second roller temperature by the heater from the reference temperature to a second specified temperature;
a power source part configured to have a power upper limit value that is smaller than a sum of heating power required to heat the heat roller and the press roller plus initial power to adjust an image forming process condition and is larger than the heating power;
a power source control part configured to control a distribution amount of the heating power to the heating element and the heater to prevent an amount of power supplied by the power source part from exceeding the power upper limit value and control supply or stop of the initial power;
a plurality of temperature sensors configured to detect respective roller temperatures of the heat roller and the press roller; and
a determination part configured to determine necessity of supplying the initial power by the power source control part based on a temperature difference between the respective roller temperatures detected by the respective temperature sensors.
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Accused Products
Abstract
Certain embodiments provide an image forming apparatus including: a print process part; a heat roller including a heating element; a press roller including a heater; a power source part having a power upper limit value that is smaller than a sum of heating power for the heat roller and the press roller plus initial power and is larger than the heating power; a power source control part to control supply or stop of the initial power; a plurality of temperature sensors to detect respective roller temperatures; and a determination part to determine necessity of supplying the initial power by the power source control part based on a temperature difference between the respective roller temperatures.
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Citations
20 Claims
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1. An image forming apparatus comprising:
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a print process part configured to form a not yet fixed developer image on a sheet; a heat roller configured to include a heating element, generate heat to the developer image on the sheet from the print process part and raise a first roller temperature by the heating element from a reference temperature to a first specified temperature; a press roller configured to press the sheet in cooperation with the heat roller, include a heater, and raise a second roller temperature by the heater from the reference temperature to a second specified temperature; a power source part configured to have a power upper limit value that is smaller than a sum of heating power required to heat the heat roller and the press roller plus initial power to adjust an image forming process condition and is larger than the heating power; a power source control part configured to control a distribution amount of the heating power to the heating element and the heater to prevent an amount of power supplied by the power source part from exceeding the power upper limit value and control supply or stop of the initial power; a plurality of temperature sensors configured to detect respective roller temperatures of the heat roller and the press roller; and a determination part configured to determine necessity of supplying the initial power by the power source control part based on a temperature difference between the respective roller temperatures detected by the respective temperature sensors. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A method of performing an initial process in an image forming apparatus, comprising:
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detecting respective roller temperatures of a heat roller and a press roller; determining necessity of supplying initial power for adjusting an image forming process condition based on a temperature difference between the respective roller temperatures; heating the heat roller and the press roller at maximum power amount within a range not exceeding a power upper limit value that is smaller than a sum of heating power to the heat roller and the press roller plus the initial power and is larger than the heating power; and starting to supply the initial power when a determination result indicates that the supplying is necessary and when the first roller temperature reaches a first specified temperature. - View Dependent Claims (15, 16, 17, 18, 19, 20)
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Specification