Abstract: A motorized sheet film cartridge comprises a light proof housing which defines an opening in its top wall. A refillable tray containing stacked sheet films is slidable in the housing. The housing includes a slidable door which displaces in a longitudinal direction horizontally over the tray and its content of sheet films between open and closed positions thereof. In its closed position, the door closes the housing opening, whereas in its open position, sheet films contained in the housing can be removed therefrom through the opening. The door is operated by a reversible DC motor which drives a pair of endless chains provided on each longitudinal side of the door for displacing the door between its open and closed positions. The motor is actuated by an external computer to appropriately open or close the door. The computer also verifies that the door is closed except when film is being loaded in the cartridge or unloaded therefrom through the opening. The cartridge is removable and portable.