Hinge unit and an image forming apparatus having the same

A hinge unit applies resilience differently according to the angle at which the hinge unit is opened, and an image forming apparatus has a cover attached by the hinge unit. The hinge unit includes a lower frame connected to a scan unit of a main body of an apparatus; an upper frame engaged with the lower frame through a hinge shaft and connected to a cover; and first and second resilient members serially arranged within the upper frame. When the cover pivots toward the scan unit at less than a predetermined angle, the hinge unit provides relatively minor resistance, whereas when the cover pivots toward the scan unit at the predetermined angle or greater, the hinge unit provides relatively greater resistance, thereby appropriately coping with the moment by weight of the cover. As a result, the improved hinge unit may enable a user to open and close the cover more comfortably.