Abstract: An electrophotographic image forming apparatus for enhancing color registration is provided. The electrophotographic image forming apparatus includes a developing unit including a photosensitive medium, an image transferring device, and a paper feeding device. The image transferring device includes a pair of conveying rollers, a conveying belt, and a plurality of transfer rollers. The conveying belt is supported by the conveying rollers and rotates around the conveying rollers and conveys a recording medium by attaching a recording medium to a surface thereof. The plurality of transfer rollers are disposed inside the conveying belt and form a transfer nip between the recording medium and the photosensitive medium. The paper feeding device provides the recording medium to the image transferring device.

Abstract: A developing unit and an image forming apparatus having the developing unit are disclosed. The developing unit includes a developing unit main body having a supporting groove that contacts and is supported by the supporting protrusion of a frame when the developing unit is mounted on the mounting frame. A photoconductor is rotatably disposed in the developing unit main body and has ends that form a supporting shaft and are supported by a supporting unit. A driven unit is disposed in the developing unit main body and geared with the driving unit when the developing unit main body is mounted on the mounting frame. One of side surfaces of the developing unit main body includes an interference unit that interferes with the mounting frame and push the developing unit main body into engagement with the driving gear when the developing main body is mounted on the mounting frame.

Abstract: An image forming apparatus includes plurality image carriers sequentially arranged, a conveying belt which conveys a print medium onto which color-separated images formed on the plurality of image carriers are oevrlapped, and a plurality of image transfer rollers installed to respectively correspond to the plurality image carriers. The conveying belt is interposed between the image transfer rollers and the image carriers. At least one of the plurality image transfer rollers is arranged to be compressed with a pressure higher than those applied to the other image transfer rollers against the image carriers.

Abstract: A developer-driving device and an image forming apparatus having the same are provided. The developer-driving device includes a photosensitive drum-driving unit that rotates a photosensitive drum and a developing roller-driving unit that rotates a developing roller. Each of the photosensitive drum-driving unit and the developing roller-driving unit includes a one-way power transmission unit. The one-way power transmission unit idles when a developer is being mounted on a main body and transmits power to the photosensitive drum and the developing roller after the developer is mounted on the main body.

Abstract: A foreign substance prevention unit use with an electro-photographic printer is installed over a waste toner injection hole such that it closes the waste toner injection hole when a photosensitive medium is separated from a main body of the electro-photographic printer, and opens the waste toner injection hole when the photosensitive medium is installed in the main body of the electro-photographic printer. The foreign substance prevention unit is formed of an elastic material.

Abstract: An electrophotographic printer including a pre-erasing unit. The pre-erasing unit includes a pre-erasing lamp to irradiate light, and a pre-transfer erasing lens to induce the light generated from the pre-transfer erasing lamp to the photosensitive drum, movably installed such that it moves to an erasure position at which the pre-transfer erasing lens is close to the photosensitive drum for erasure, and moves to a retracted position spaced apart from the photosensitive drum so as not to interfere therewith when the photosensitive drum unit is being mounted or dismounted. The pre-erasing unit may further include an elastic member to provide elasticity in a direction in which the pre-transfer erasing lens moves to the retracted position.

Abstract: A developer driving apparatus and an image forming apparatus including the developer driving apparatus are provided. The developer driving apparatus includes a driving source; a power transmitting unit, and a power controlling unit. The power transmitting unit selectively transmits power generated by the driving source to development rollers of the developers to drive the developers. The power controlling unit is provided between the driving source and the power transmitting unit and controls the power so that the power is transmitted to the corresponding developer. Accordingly, the plurality of the drive developers can be driven using two power controlling units, that is, two electronic clutches, unlike conventional apparatuses that use four electronic clutches. Accordingly, the manufacturing cost of the image forming apparatus can be reduced. Also, the number of the power controlling units can be reduced and the space occupied by the power controlling units can be reduced.

Abstract: An electrophotographic includes a main frame, a photosensitive drum unit having a photosensitive drum and vertically detachably installed on the main frame, a plurality of development units each having a developing roller and detachably installed on the main frame while sliding in a horizontal direction, and a first door openably installed for mounting or dismounting the plurality of development units.

Abstract: A door shock absorber is provided to absorb noise and shock when a door is opened, and an image forming apparatus employing the same. The door shock absorber includes a first guide rail included in a door mounted on a case used as an outer covering. A first spring is contained by the first guide rail. A link has a first end hingedly connected to the inside of the case, and a second end connected to the first guide rail and able to move in the direction of the first guide rail. When the door is opened, the second end of the link moves in the direction of the first guide rail and compresses the first spring.

Abstract: An electrophotographic image forming apparatus has a development unit with a photoconductor. A transport belt conveys a printing medium onto which a toner image is transferred from the photoconductor. A separator is disposed inside the transport belt, and is capable of extending outwardly to push the printing medium to separate the printing medium from the transport belt after transferring the toner image.

Abstract: A system to replace a photosensitive unit and a transfer unit in a printer includes a frame provided in a printer body, and a locking unit which is provided in the frame and simultaneously locks and unlocks the photosensitive unit and the transfer unit that enter via an entrance of the printer body and are seated in a mounting location. The locking unit may include a rotating lever, a rotating cam, and a connection bar which connects the rotating cam to the rotating lever.

Abstract: An image forming apparatus includes a shaft, a shaft support portion rotatably supporting the shaft, a shaft gear provided at an end portion of the shaft in a lengthwise direction, and a first gear engaged with the shaft gear and rotating the shaft gear. The rotation of the first gear applies a force acting toward the shaft support potion and the shaft contacts the shaft support portion by the force during rotation so that vibration of the shaft is restricted. An image forming apparatus includes a case having a door that can be opened and closed, a shaft provided in the case, a shaft support portion rotatably supporting the shaft, a shaft gear provided at an end portion of the shaft in a lengthwise direction, and a first gear engaged with the shaft gear and rotating the shaft gear. The first gear is engaged with the shaft gear when the door is closed and disengaged from the shaft gear when the door is open.

Abstract: A paper feeding mechanism for an image forming apparatus includes a drive roller rotated by a first shaft driven by a motor. A press roller is supported by a second shaft which is parallel to and spaced apart from the first shaft. The press roller is pressed against the drive roller, and is driven by the drive roller. A cam pushes the second shaft (and therefore the press roller) away from the drive roller to prevent unnecessary external forces from being exerted on paper being fed through the rollers. The cam is actuated by clutching means for transferring rotating force of the first shaft to the cam to rotate the cam when it is necessary to move the press roller away from the drive roller.

Abstract: A waste toner agitator for an electrophotographic image forming apparatus includes a plurality of protrusions protrusively formed on a top surface of a cassette and, an actuator that is pivotably installed on sidewalls of the waste toner container. The actuator has a shaft that is installed inside of the waste toner container and provides a plurality of agitating wings for agitating the waste toner, and also includes a pivoting part that is installed outside of the waste toner container, is connected to the shaft, and contacts each of the protrusions. The waste toner container further includes a plurality of elastic members that are installed opposite to the pivoting part and are placed between a plurality of supporting parts provided outside of the waste toner container, and return the actuator to its original position after the actuator contacts the protrusion and is pivoted away from its original position.

Abstract: A high voltage switching equipment for sequentially supplying a high voltage to color developing devices, for developing an electrostatic latent image formed on a photoconductive medium of a color image forming apparatus using color toners includes high voltage applying terminals respectively formed in rear ends of fixed color developing devices contacting the photoconductive medium through a nip, a high voltage applying substrate, within which a high voltage circuit is installed, on which connector terminal strips connected to the each high voltage applying terminal are provided on one side, and on which first terminal strips connected to the high voltage circuit and second terminal strips connected to the connector terminal strips are arranged in pairs on the other side with a constant distance, and a high voltage connecting unit connecting the first terminal strips and the second terminal strips arranged on the high voltage applying substrate, so that the high voltage is supplied to a relevant developing d

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 shaft support bushing with an improved structure, and a method of combining a bushing with a bracket. The bushing includes: a body having a coupling hole through which the shaft is inserted and being fitted into an installation hole of the bracket; a flange extending from one end of the body over a part of the bracket; and a skirt portion formed on the other end of the body to prevent the body from separating from the installation hole. The shaft assembling method includes: forming an installation hole in a bracket; coupling a bushing into the installation hole, the bushing comprised of a body, which has a coupling hole into which a shaft is inserted, and a flange extending from one end of the body over a part of the bracket; pressing the other end of the body to form a skirt portion preventing the bushing from separating from the bracket; and coupling the shaft into the installation hole.

Abstract: An image forming apparatus including a main body, a photoconductive unit disposed in the main body to develop an image, a transferring unit removably disposed in the main body in contact with the photoconductive unit to transfer the image from the photoconductive unit onto a recording medium, a locking/releasing unit to lock and unlock a mounting position of the transferring unit with respect to the photoconductive unit, and a checking unit to check whether the transferring unit is mounted by the locking/releasing unit. Accordingly, even if the user may inadvertently operate the image forming apparatus while not operating the locking/releasing unit so that the transferring unit and the photoconductive unit are not fixed to each other, the image forming apparatus notifies the user.

Abstract: A foreign substance prevention unit use with an electro-photographic printer is installed over a waste toner injection hole such that it closes the waste toner injection hole when a photosensitive medium is separated from a main body of the electro-photographic printer, and opens the waste toner injection hole when the photosensitive medium is installed in the main body of the electro-photographic printer. The foreign substance prevention unit is formed of an elastic material.

Abstract: A wasted toner storing apparatus and a dry type electrophotographic image forming apparatus using the same. The wasted toner storing apparatus includes a wasted toner container accommodating wasted toner generated during a printing process, and a dispersing member inside the wasted toner container, dispersing the wasted toner inside the wasted toner container by rotation of the dispersing member.