Image forming apparatus

An image forming apparatus configured to form an image on a recording medium, the image forming apparatus comprising:

• a rotational photosensitive member;
• an exposure device including a plurality of light emitting elements and a driving unit, the plurality of light emitting elements being arranged along a rotational axis direction of the photosensitive member and configured to emit light to expose the photosensitive member, the driving unit being configured to drive the plurality of light emitting elements;
• an output unit configured to superimpose a clock signal for driving the exposure device on image data for controlling lighting-up of the plurality of light emitting elements, and output the image data as serial data;
• a generation unit configured to recover and generate the clock signal superimposed on the image data;
• a conversion unit configured to receive the serial data output from the output unit and convert the received serial data into parallel data;
• a lock signal output unit configured to lock the generation unit and output a lock signal in a case where the generation unit generates the clock signal at a predetermined frequency;
• and
• a control unit configured to count a number of times that the conversion unit has not received the serial data normally during a predetermined period, and unlock the generation unit in a case where the number of times that the conversion unit has not received the serial data normally exceeds a predetermined value.