| 摘要 |
PURPOSE:To make control easy and to suppress an increase in cost by detecting the initial temp. on the surface of a heating roller in the stage of throwing a power source, setting the surface temp. according to the detected value and prohibiting the temp. control by a temp. detecting element until the surface temp. attains the fixing temp. CONSTITUTION:The temp. range up to the fixing temp. Ts is divided to regions A1-A3 and on times the corresponding heaters are designated as t1-t3. The heater on-times t1-t3 in the regions A1-A3 are so set that the surface temp. rises up to the fixing temp. Ts or above when the initial temp. TINT is at the lowest temp. of each region. Said time are so set that the surface temp. does not exceed the max. permissible temp. TMAX when the temp. TINT is at the max. temp. of each region. The heater 2 is turned on and off according to the output from a thermistor 3 when a timer TIN2 is timed up so that the surface temp. of the heating roller 1 is maintained at the fixing temp. The temp. control by the temp. detecting element is prohibited until the surface temp. attains the fixing temp. The waiting time is thus reduced at the low cost without being influenced by the responsiveness of the temp. detecting element and without requiring intricate control means. |
