Abstract: An image forming apparatus and a control method thereof, the control method including applying a minimum current to a light emitting element, and applying one or more higher currents, up to a maximum current, to the light emitting element, if a light receiving element fails to detect light emitted by the light emitting element.

Abstract: An image forming apparatus and a control method thereof, the control method including applying a minimum current to a light emitting element, and applying one or more higher currents, up to a maximum current, to the light emitting element, if a light receiving element fails to detect light emitted by the light emitting element.

Abstract: An image forming apparatus having a duplex printing capability includes a paper discharging unit to discharge a printed sheet of paper to a paper discharge plate, and a duplex printing unit. The duplex printing unit includes a paper reversing unit to reverse a printing side of the one-side printed sheet of paper in a duplex print mode and includes a paper transport passage separated from the paper discharging unit, and a transport direction switcher to switch a paper transport direction between the paper discharging unit and paper reversing unit, whereby the sheet of paper is transported towards either the paper discharging unit or the paper reversing unit based on a sensed quantity of sheets of paper discharged to the paper discharge plate, and discharging the sheet of paper through the paper reversing unit where the sensed quantity of sheets of paper is greater than or equal to a predetermined value.