Abstract: An optional tray fastening device of an image forming apparatus, for providing a fastening connection between an optional receiving tray moving in and out with respect to a main body of the image forming apparatus and the main body when mounting the optional tray to a lower part of the main body, includes a fastening depression formed at a lower part of the main body; a connection boss that protrudes from an upper part of the optional tray to be inserted in the fastening depression; and a key member that restrains escape of the connection boss from the fastening depression.

Abstract: An apparatus for adjusting a fixing pressure of an image forming apparatus is provided. The apparatus for adjusting the fixing pressure includes a pair of pressing members to rotatably support an axis of a first roller from both ends and to rotate about a hinge shaft to cause the first roller to press against a second 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.

Abstract: A paper arranging device includes a driving roller and an idle roller disposed adjacent to each other to form a nip, a first sensor to sense a location of moving paper, and a lever having a first end which extends to a perimeter of the nip to block a tip of the paper moving toward the nip and the other end which extends to a perimeter of the sensor, the lever being rotatable with respect to a predetermined pivot axis between the first end and the second end of the lever. When the first end of the lever is pressed by the tip of the moving paper and reaches a first position, the first sensor determines that the tip of the paper is entering the nip and generates a first sensing signal. When the first end of the lever is pressed by the tip of the moving paper and reaches a second position at which the paper has proceeded farther than at the first position, the first sensor determines that the tip of the paper passes through the nip and generates a second sensing signal.

Abstract: An apparatus for adjusting a fixing pressure of an image forming apparatus is provided. The apparatus for adjusting the fixing pressure includes a pair of pressing members to rotatably support an axis of a first roller from both ends and to rotate about a hinge shaft to cause the first roller to press against a second 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.

Abstract: An optional tray fastening device of an image forming apparatus, for providing a fastening connection between an optional receiving tray moving in and out with respect to a main body of the image forming apparatus and the main body when mounting the optional tray to a lower part of the main body, includes a fastening depression formed at a lower part of the main body; a connection boss that protrudes from an upper part of the optional tray to be inserted in the fastening depression; and a key member that restrains escape of the connection boss from the fastening depression.

Abstract: A paper arranging device includes a driving roller and an idle roller disposed adjacent to each other to form a nip, a first sensor to sense a location of moving paper, and a lever having a first end which extends to a perimeter of the nip to block a tip of the paper moving toward the nip and the other end which extends to a perimeter of the sensor, the lever being rotatable with respect to a predetermined pivot axis between the first end and the second end of the lever. When the first end of the lever is pressed by the tip of the moving paper and reaches a first position, the first sensor determines that the tip of the paper is entering the nip and generates a first sensing signal. When the first end of the lever is pressed by the tip of the moving paper and reaches a second position at which the paper has proceeded farther than at the first position, the first sensor determines that the tip of the paper passes through the nip and generates a second sensing signal.

Abstract: A paper feeding unit driving device for an electrophotographic processor having a feed roller gear and a convey roller gear, a paper feed roller, and a convey roller, includes: a latch having first and second latch lugs and a first elastic member, a first shaft, a first clutch-spring, a first collar, a first stop, and a first hub, a second shaft, a second clutch-spring, a second collar, a second stop, and a cam, and a solenoid having a plunger and a second elastic member.