Abstract: A cartridge which is detachably mountable in a printer main body includes a rotatable member and a coupler to rotate the rotatable member by receiving rotation power from an external source. The coupler includes a coupler body connected to the rotatable member and a coupler arm provided at the coupler body so as to be movable to a first position and a second position. The first position is farther from a center of rotation of the coupler than the second position, and the coupler arm is to push and rotate the coupler body when the rotation power is received by the coupler. The coupler also includes an elastic member to apply an elastic force to the coupler arm in a direction in which the coupler arm returns to the first position from the second position.

Abstract: A cartridge which is detachably mountable in a printer main body includes a rotatable member and a coupler to rotate the rotatable member by receiving rotation power from an external source. The coupler includes a coupler body connected to the rotatable member and a coupler arm provided at the coupler body so as to be movable to a first position and a second position. The first position is farther from a center of rotation of the coupler than the second position, and the coupler arm is to push and rotate the coupler body when the rotation power is received by the coupler. The coupler also includes an elastic member to apply an elastic force to the coupler arm in a direction in which the coupler arm returns to the first position from the second position.

Abstract: An electrophotographic image forming apparatus includes a driving device including a first gear and a second gear, a power transmitter configured to transfer a rotational force applied in one direction from the motor to the first and second gears; a cam configured to set the power transmitter to one of a release mode in which the motor is disconnected from the first and second gears, a first connection mode in which one of the first and second gears is connected to the motor, and a second connection mode in which the other of the first and second gears is connected to the motor; and a clutch configured to selectively transfer the rotational force applied in the one direction from the motor to the cam.

Abstract: An electrophotographic image forming apparatus includes a driving device including a first gear and a second gear, a power transmitter configured to transfer a rotational force applied in one direction from the motor to the first and second gears; a cam configured to set the power transmitter to one of a release mode in which the motor is disconnected from the first and second gears, a first connection mode in which one of the first and second gears is connected to the motor, and a second connection mode in which the other of the first and second gears is connected to the motor; and a clutch configured to selectively transfer the rotational force applied in the one direction from the motor to the cam.

Abstract: A scanning apparatus and an image forming apparatus having the same. The scanning apparatus includes: a main body having a scanning unit; a cover to open and close upon an upper surface of the main body; a hinge unit disposed on one of the main body and the cover so that the cover is rotatable with respect to the main body; a hinge accommodating unit disposed on the other of the main body and the cover to accommodate the hinge unit so that the cover is movable in an upward and downward direction with respect to the upper surface of the main body; and a movement restricting unit disposed on at least one of the hinge unit and the hinge accommodating unit to restrict a movement of the cover in the upward and downward direction.

Abstract: An image forming apparatus and a method of driving the same are provided in which, if a driving environment is determined to be a low temperature environment, a driving load of an image forming unit is decreased by repeating driving and stopping a driving motor under a high load driving condition to generate a torque higher than a torque generated under a normal warm-up driving condition; and a warm-up operation is performed by driving the driving motor under the normal warm-up driving condition.

Abstract: An image forming apparatus and a method of driving the same are provided in which, if a driving environment is determined to be a low temperature environment, a driving load of an image forming unit is decreased by repeating driving and stopping a driving motor under a high load driving condition to generate a torque higher than a torque generated under a normal warm-up driving condition; and a warm-up operation is performed by driving the driving motor under the normal warm-up driving condition.

Abstract: A document feeding apparatus includes a first delivery roller delivering a document sheet discharged from a fixing unit, a second delivery roller discharging the document sheet to a paper delivery tray, a motor driving the second delivery roller, a lever installed at the downstream, or upstream, side of the first delivery roller out of a document sheet transporting pathway, which rotates at a predetermined angle when contacting the document sheet and returns to an original position when not contacting the document sheet, a sensor sensing a rotation time and a returning time of the lever, and a controller determining a double feeding or slipping state of the document sheet based on a signal transferred from the sensor regarding the rotation time and the returning time of the lever, and controlling the driving speed of the motor according to the determination result.

Abstract: A scanning apparatus and an image forming apparatus having the same. The scanning apparatus includes: a main body having a scanning unit; a cover to open and close upon an upper surface of the main body; a hinge unit disposed on one of the main body and the cover so that the cover is rotatable with respect to the main body; a hinge accommodating unit disposed on the other of the main body and the cover to accommodate the hinge unit so that the cover is movable in an upward and downward direction with respect to the upper surface of the main body; and a movement restricting unit disposed on at least one of the hinge unit and the hinge accommodating unit to restrict a movement of the cover in the upward and downward direction.

Abstract: An image forming apparatus includes a discharging roller decelerating unit and a method of decelerating discharging rollers. The image forming apparatus includes a print unit, discharging rollers, a sensor unit that sensing a trailing edge of paper, and the discharging roller decelerating unit. The method includes detecting a trailing edge of paper using a sensor unit and decelerating the discharging rollers after a predetermined period of delay time subsequent to the sensing of the trailing edge of the paper. Accordingly, even when there is a difference between the sensing moments of the trailing edge of the paper, the decelerating moments of the discharging rollers are stabilized, and thus the paper can be uniformly stacked regardless of double-sided printing or single-sided printing, even when the paper is discharged at a high speed.

Abstract: A power transmitter, including a driving gear rotated by a driving motor, a driven gear rotatably coupled with the driving gear through a coupler, and a power interruption unit to be broken when the driven gear is overloaded so as to release the coupling between the driven gear and the coupler such that power transmission to the driven gear is cut off.

Abstract: A document feeding apparatus includes a first delivery roller delivering a document sheet discharged from a fixing unit, a second delivery roller discharging the document sheet to a paper delivery tray, a motor driving the second delivery roller, a lever installed at the downstream, or upstream, side of the first delivery roller out of a document sheet transporting pathway, which rotates at a predetermined angle when contacting the document sheet and returns to an original position when not contacting the document sheet, a sensor sensing a rotation time and a returning time of the lever, and a controller determining a double feeding or slipping state of the document sheet based on a signal transferred from the sensor regarding the rotation time and the returning time of the lever, and controlling the driving speed of the motor according to the determination result.