Apparatus for adjusting fixing pressure and image forming apparatus having the same

An image forming apparatus, comprising:

• a pressing roller and a heating roller configured to rotate, while facing each other, and to fix a toner image onto a printing medium;
• and
• a fixing pressure adjusting apparatus configured to adjust a pressure with which the pressing roller presses against the heating roller, the fixing pressure adjusting apparatus comprising:
• a pair of pressing members to rotatably support an axis of the pressing roller from both ends, and to rotate about a hinge shaft to cause the pressing roller to press against the heating roller,
• a pair of hinge cams to move the hinge shaft of the pair of pressing members in either of two directions,
• a driving unit to rotate the pair of hinge cams, and
• a control unit to control the driving unit to adjust the position of the hinge shaft,
• wherein the driving unit comprises a cam shaft on which the pair of hinge cams are disposed, and the driving unit rotates the cam shaft with a rotational force of a fixing motor which drives the pressing roller or the heating roller.

An image forming apparatus comprising:

• a thickness selector receiving an input as to a thickness of a print medium;
• a pressing roller and a heating roller configured to rotate, while facing each other, and to fix a toner image onto the print medium;
• a plurality of elastic members disposed at upper ends of the pressing roller to pull the pressing roller toward the heating roller in response to a pressure signal from the thickness selector;
• a fixing pressure adjuster to set a pressure at which the pressing roller presses against the heating roller, wherein the pressure is determined based upon the input received by the thickness selector;
• and
• a pair of curved hinge cams to move the pressing roller in either of two directions.