Abstract: A coupling apparatus, a development cartridge, and an electrophotographic printer having the coupling apparatus. The coupling apparatus transfers a rotation force in a connected state. The coupling apparatus has a first coupler having a cylindrical-type connection portion at an end and a spiral rib spirally protruded at an outer circumference of the connection portion; and a second coupler having a circular-type main hole depressed at an end corresponding to the connection portion, and a spiral groove formed at an inner circumference of the main hole corresponding to the spiral rib. The connection portion and the spiral rib are relatively connected with the main hole and the spiral groove by being pressed, and transmit a rotation force by being rotated together.

Abstract: A coupling apparatus to transfer a rotation force in a connected state. The apparatus has a first coupler having a first sloping rib formed at one end thereof and sloped in a rotation direction, and a second coupler having a second sloping rib formed at an inner circumference of the second coupler and sloped to correspond to the first sloping rib. The sloping ribs are connected by being pressed as the first coupler and the second coupler are relatively rotated, and rotation axes of the couplers coincide when the sloping ribs are completely connected.

Abstract: A coupling apparatus capable of being connected by sliding and transferring power when being connected. The apparatus has a first coupler having a plurality of first ribs protruding at an outer circumference of a body at a regular interval and a second coupler having a connection portion to embrace and be separated from the body of the first coupler, and a plurality of second ribs protruding at an inner circumference of the connection portion, the plurality of second ribs being connected between the plurality of first ribs, wherein each of front ends of the first ribs and the second ribs have sloping sides sloped in a predetermined direction, and the first ribs include a rib having a relatively longer length than the other ribs.

Abstract: A paper delivery device in a printer selectively changes a stacking direction of printed and ejected paper and stacks paper. The device includes a first tray, and a second tray to pivot to a first position where paper is guided to the first tray and to a second position where the paper is stacked so that a side of an image of the paper is opposite to a side of an image of the first tray. The device also includes a first guide and a second guide to provide a side and the other side, respectively, of an ejecting route so that the paper is ejected to the first tray. The device includes a first roller and a second roller, each of the first and second rollers being installed in the first guide and second guide of the ejecting route. The device includes an ascending unit installed in the second tray to ascend the second roller so that the second roller is engaged with the first roller in the first position, and the second roller is placed under the second guide in the second position.

Abstract: A paper supply cassette includes a main body to which a paper supply roller is coupled, a container provided to slid e into/from the main body, a first lever installed at the main body to swing, a first gear installed at one side of the first lever to rotate and drive a paper supply roller by being meshed with a drive gear provided at the printer, a first elastic member to apply an elastic force to the first lever in a direction in which the first gear is meshed with the drive gear, and a locking unit to selectively lock the first lever in a state in which the first gear is separated from the drive gear. Thus, the damage to or deformation of the first gear of the paper supply cassette is prevented. Also, since the paper is stably supplied, the quality of an image can be improved.

Abstract: A coupling apparatus capable of being connected by sliding and transferring power when being connected . The apparatus has a first coupler having a plurality of first ribs protruding at an outer circumference of a body at a regular interval and a second coupler having a connection portion to embrace and be separated from the body of the first coupler, and a plurality of second ribs protruding at an inner circumference of the connection portion, the plurality of second ribs being connected between the plurality of first ribs, wherein each of front ends of the first ribs and the second ribs have sloping sides sloped in a predetermined direction, and the first ribs include a rib having a relatively longer length than the other ribs.

Abstract: A coupling apparatus, a development cartridge, and an electrophotographic printer having the coupling apparatus. The coupling apparatus transfers a rotation force in a connected state. The coupling apparatus has a first coupler having a cylindrical-type connection portion at an end and a spiral rib spirally protruded at an outer circumference of the connection portion; and a second coupler having a circular-type main hole depressed at an end corresponding to the connection portion, and a spiral groove formed at an inner circumference of the main hole corresponding to the spiral rib. The connection portion and the spiral rib are relatively connected with the main hole and the spiral groove by being pressed, and transmit a rotation force by being rotated together.

Abstract: A coupling apparatus to transfer a rotation force in a connected state. The apparatus has a first coupler having a first sloping rib formed at one end thereof and sloped in a rotation direction, and a second coupler having a second sloping rib formed at an inner circumference of the second coupler and sloped to correspond to the first sloping rib. The sloping ribs are connected by being pressed as the first coupler and the second coupler are relatively rotated, and rotation axes of the couplers coincide when the sloping ribs are completely connected.