Fixing Device, Image Forming Apparatus

摘要

A fixing device is provided with a magnetic flux generating unit, first and second rotary bodies, a fixing belt, a temperature sensing portion, a stopped time measuring portion, an abnormality determination portion, and a heating delay portion. The fixing belt extends between the first and second rotary bodies, and is heated by the first rotary body. The temperature sensing portion is disposed downstream of the first rotary body and senses the temperature of the fixing belt. The stopped time measuring portion measures a time period after heating has been stopped before an instruction to start heating is inputted. The abnormality determination portion determines any abnormality in the fixing belt based on a change in temperature after heating has started. When a stopped time is shorter than a pre-configured time period, the heating delay portion delays the start time via magnetic flux based on the instruction to start heating.

主权项

1. A fixing device comprising:
a magnetic flux generating unit; a first rotary body configured to generate heat through action of magnetic flux generated by the magnetic flux generating unit; a second rotary body disposed parallel with respect to the first rotary body; a fixing belt extended on and between the first rotary body and the second rotary body, and is to be heated by the first rotary body; a temperature sensing portion disposed in an upstream side from the second rotary body in a rotation direction of the fixing belt, but in a downstream side from the first rotary body in the rotation direction of the fixing belt, and capable of sensing temperature of the fixing belt; a stopped time measuring portion configured to measure a time period during which heating has been stopped before a heating-start instruction for heating the fixing belt is inputted to the magnetic flux generating unit; an abnormality determination portion configured to determine, after heating of the fixing belt is started, abnormality of the fixing belt based on a change rate over time of temperature sensed using the temperature sensing portion; and a heating delay portion configured to, under a condition that the stopped time measured by the stopped time measuring portion is shorter than a configured time period determined in advance, delay, for a predetermined time period, a timing at which heating of the fixing belt is to be started through generation of magnetic flux by the magnetic flux generating unit based on the heating-start instruction.