Image forming apparatus

摘要

An image forming apparatus includes a heating element that generates heat, a temperature detector that detects a temperature of the heating element, a resistor that divides a detection result of the temperature detector and a predetermined reference voltage, a disconnection detector that detects a disconnection of the temperature detector, a converter that converts the divided voltage value into a digital signal and outputs the digital signal to a controller, a comparing unit that inverts its output on the basis of a predetermined threshold, a delay circuit that delays an increase in an output voltage of the comparing unit, a discharge circuit that quickly discharges the output voltage of the comparing unit, a latch circuit connected to an output of the discharge circuit, and a power supply path connecting and disconnecting unit that is connected to the latch circuit and connects and disconnects a power supply path to the heating element.

主权项

1. An image forming apparatus comprising:
a heating element configured to generate heat when a current is applied thereto; a temperature detector that is disposed in the vicinity of the heating element and is configured to detect a temperature of the heating element; a resistor configured to divide a detection result of the temperature detector and a predetermined reference voltage; a disconnection detector that is connected in parallel to the resistor, and is configured to detect a disconnection of the temperature detector; a converter configured to convert the divided voltage value into a digital signal and to output the digital signal to a controller; a comparing unit configured to invert an output of the comparing unit on the basis of a comparison between the divided voltage value and a predetermined threshold, and a comparison between an output of the disconnection detector and the predetermined threshold; a delay circuit configured to delay an increase in an output voltage of the comparing unit; a discharge circuit configured to quickly discharge the output voltage of the comparing unit; a latch circuit that includes a flip-flop connected to an output of the discharge circuit; and a power supply path connecting and disconnecting unit that is connected to the latch circuit, and is configured to connect and disconnect a power supply path to the heating element.