Abstract: An image forming apparatus includes a control unit to identify a type of an option unit using pre-stored ID information including information regarding a universal interface to which at least one type of option unit can be connected, a power supply unit, and an option unit connected to the universal interface. A plurality of switches is located along a power supply path between the option unit and the power supply unit. The pre-stored ID information includes the type of the option unit and level of power allowed for the type of option unit. The control unit controls on/off states of the plurality of switches so that power corresponding to the identified type of option unit can be supplied to the option unit. Accordingly, possible damage to the image forming apparatus due to inappropriate connection between the option unit and the image forming apparatus is prevented.

Abstract: An image forming apparatus includes a control unit to identify a type of an option unit using pre-stored ID information including information regarding a universal interface to which at least one type of option unit can be connected, a power supply unit, and an option unit connected to the universal interface. A plurality of switches is located along a power supply path between the option unit and the power supply unit. The pre-stored ID information includes the type of the option unit and level of power allowed for the type of option unit. The control unit controls on/off states of the plurality of switches so that power corresponding to the identified type of option unit can be supplied to the option unit. Accordingly, possible damage to the image forming apparatus due to inappropriate connection between the option unit and the image forming apparatus is prevented.

Abstract: An image forming apparatus includes a main body having an image forming unit, a medium feeding unit installed in the main body, having a loading plate to load a print medium thereon and to feed the loaded print medium to the image forming unit, a medium sensing unit which comprises an interference unit which operates to correspond with the print medium loaded on the loading plate and the print medium fed by the medium feeding unit and the print medium being in a registration position on a feeding path, and a sensor having a sensing position and sensing a movement of the interference unit, and a controller to determine whether the print medium is loaded on the loading plate and whether the print medium is in the registration position on the feeding path, based on a sensing signal of the sensor.

Abstract: An image forming apparatus includes an output control unit to change an output of an optical sensor to collectively recognize a plurality of print processes for a print job. The output control unit includes a first actuator to recognize whether paper is present in a printing medium cassette and a second actuator to recognize whether paper is being conveyed. This makes it possible to recognize whether paper is present in a printing medium cassette and whether paper is being conveyed based on the output of the optical sensor, thereby reducing a financial burden and preventing a reduction in a task efficiency of an optical sensor installation.