Image formation apparatus

An image formation apparatus comprising process means for forming an image on a sheet fed thereto, a heated member having a heat source disposed within said apparatus and adapted to heat upon supply of electric power thereto, means for detecting the temperature by said heat source, temperature control means for controlling the electric power supplied to said heat source in accordance with the detected temperature, means for detecting disconnection of an element in said detecting means for detecting the temperature by said heat source, malfunction detecting means for detecting a malfunction condition in said apparatus, interruption means for interrupting operation of said apparatus in accordance with an output of said malfunction detecting means, and control means for operating said disconnection detecting means after a predetermined time from a point in time when said apparatus restarts operation after release from the malfunction condition.

An image formation apparatus comprising a main switch for enabling said apparatus and initiating a preparatory operation for image formation, process means for forming an image on a recording sheet, a heat source disposed within said apparatus and adapted to heat upon supply of electric power thereto, a temperature detecting element for effecting the temperature control of said heat source, means for detecting disconnection of said temperature detecting element, said disconnection detecting means having comparing means for comparing the output signal of said temperature detecting element with a reference signal to detect the disconnection, wait means for causing the preparatory operation for image formation to take place after closing of the main switch of said apparatus and for displaying that the apparatus is in its preparatory condition, said wait means having a wait displayer, and control means for operating said wait means by said disconnection detecting means to display the disconnected condition and for preventing start of the image formation by said process means.

A temperature control device comprising a heated member having an electrically powered heat source, means for detecting the temperature of said heated member, temperature control means for controlling the electric power supplied to said heat source in accordance with the detected temperature, means for detecting disconnection of an element in said detecting means for detecting the temperature of said heated member, interruption means for interrupting operation of said temperature control means in accordance with a malfunction condition detection signal, and control means for operating said disconnection detecting means after a predetermined time from a point in time when said temperature control means restarts operation after release from the malfunction condition.