WARM-UP TIME PREDICTING METHOD OF HEATING BODY OF HEATING DEVICE AND IMAGE FORMING DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a warm-up time predicting method of a heating body of a heating device capable of predicting time length from start of heating to reach to target temperature of the heating body with high accuracy and contriving shortening of first print time and energy saving while securing fixability and an image forming device. SOLUTION: Length of heating time from the start of heating to the reach to the target temperature of the heating body 21 is predicted based on a linear function to use an inverse number of a detected voltage value of a thermistor 22 and detected time of the thermistor 22 as variables, transportation start time of a recording material P is decided so as to satisfy t3-5<t4<t3 when the predicted length of heating time from the start of heating to the reach to the target temperature of the heating body 21 is defined as t3, length of transportation time from the start of heating to irruption of the tip in the transporting direction of the recording material P in a nip is defined as t4 and time length to be required for one rotation of a pressurization roller 25 is defined as t5.