US 2002/0118977 A1 · Fixing device and image forming apparatus

Abstract

In a fixing device of the film heating type and the pressure rotary member driving type and an image forming apparatus provided with this fixing device, at the start of printing, the output of a thermistor near a heater is detected, and when the temperature difference ΔT=T2−T1 between the detected temperature T1 and the fixing temperature T2 is smaller than a desired temperature T0, the raising timing of the heater is delayed. Thereby, a pressure roller is not-excessively warmed at hot start and slip can be prevented. Also, in the image forming apparatus having the film heating type fixing device, in the next printing after the lapse of a predetermined time after the termination of a printing operation, the target temperature and heater electrical energization starting timing of the fixing device are changed in conformity with the temperature of the fixing device. The apparatus has an atmospheric temperature sensor, and in the next printing after the lapse of a predetermined time after the termination f a printing operation, the forget temperature and heater electrical energization timing of the fixing device during the initial rotation operation in the printing, operation are changed in conformity with the atmospheric temperature detected by the atmospheric temperature sensor and the temperature of the fixing device.

Claims20

Dependent claims

A fixing device comprising:

a heater;
a temperature detecting element for detecting a temperature of said heater;
and
temperature controlling means for controlling an electrical energization of said heater so that a detected temperature by said temperature detecting element may become a target temperature,
wherein said temperature controlling means, when starting the electrical energization of said heater to fix an unfixed image formed on a recording material, starts the electrical energization of said heater at timing determined on the basis of the detected temperature by said temperature detecting element before the electrical energization of said heater is started.

2 more elements

A temperature controlling method in a fixing device comprising a heater, a temperature detecting element for detecting a temperature of said heater, and temperature controlling means for controlling an electrical energization of said heater so that a detected temperature by said temperature detecting element may become a target temperature, said method comprising;

determining the electrical energization timing of said heater on the basis of the detected temperature by said temperature detecting element before the electrical energization of said heater is started when an unfixed image formed on a recording material, is to be fixed;
and
starting the electrical energization of the heater at a timing determined by the determining step.

An image forming apparatus comprising:

image forming process means for forming an unfixed image on a recording material;
and
fixing means provided with a heater, a temperature detecting element for detecting a temperature of said heater, and temperature controlling means for controlling an electrical energization of said heater so that a detected temperature by said temperature detecting element may become a target temperature,
wherein when the electrical energization of said heater is to be started at predetermined timing with respect to the recording material to fix the unfixed image formed on the fed recording material, said temperature controlling means starts the electrical energization of said heater at timing determined on the basis of the detected temperature by said temperature detecting element before the electrical energization of said heater is started.

1 more element

Dependencies are inferred from the claim text.

Fixing device and image forming apparatus

Life of this patent

Fixing device and image forming apparatus

Life of this patent

Abstract

Claims20