Abstract: An image forming apparatus includes a transfer belt having a light penetrating portion formed at one side of an edge portion of the transfer belt, a protection tape adhered to both sides of the edge portion to cover the light penetrating portion, and a guide member attached to one side of the protection tape. A plurality of rotation rollers drive the transfer belt in a caterpillar-type manner and include a guide groove formed at both ends of each rotation roller such that the guide member is inserted therein. A sensing body receives one end of the transfer belt to be positioned therein. A first sensing element and a second sensing element are disposed at both sides of the transfer belt such that a second distance from a transfer surface of the transfer belt to the second sensing element is longer than a first distance from the other surface of the transfer belt to the first sensing element.

Abstract: An transfer belt for use in an image forming apparatus that senses an initial printing position. The belt includes a PC alloy portion, protective tape, and an error prevention section. The PC alloy portion includes a position sensing hole extending therethrough and disposed proximate to an edge of the PC alloy portion. The PC alloy portion is usable to determine an initial printing position. The protective tape is attached to upper sides and lower sides of both edges of the PC alloy portion. The error prevention section is insertable into the position sensing hole and has a thickness substantially equivalent to the PC alloy located around the position sensing hole.

Abstract: An image forming apparatus includes a transfer belt onto which a toner image formed on an outer surface of a photosensitive medium is transferred. The transfer belt moves along a predetermined closed path while being supported by a plurality of rollers. A protection unit protects the transfer belt by being attached to at least one of an inner surface and an outer surface of a non-transferring region of the transfer belt. A control unit controls the transfer belt so that an overlapping part where the protection unit is attached to the transfer belt, and a seam part where two ends of the transfer belt are connected stops at a predetermined location after printing. The image forming apparatus substantially prevents partial loss of an image by preventing wrinkles in the transfer belt.

Abstract: A waste toner collecting device of an electrophotographic printer is provided. The device includes a housing to temporarily hold waste toner removed from an image holding body, an exhaust guide member including an exhaust hole through which the waste toner is exhausted, an opening and closing unit to open and close the exhaust hole, an inlet guide member having an inlet path to connect the exhaust hole to an inlet of a waste toner collection tank, and an elastic member which elastically supports the inlet guide member so that a gap between the exhaust hole and an inlet side of the inlet path is closely maintained when the exhaust guide member ascends and descends.

Abstract: A photoreceptive unit and transfer unit replacement system of a printer includes a door opening and closing an entrance formed above a portion where a photoreceptive unit and a transfer unit are installed in a main body of the printer. A first guide rail is provided at a frame of the main body to guide the photoreceptive unit which enters through the entrance and descends. A second guide rail is provided at the frame to guide the transfer unit which enters through the entrance and descends. A locking unit locks and unlocks the photoreceptive unit and the transfer unit according to an operation of opening and closing the door. Thus, since the operation of opening and closing the door are performed according to the operation of locking and unlocking the respective photoreceptive unit and transfer units, and the photoreceptive unit and transfer units pass through the entrance disposed above the units, a replacement process can be performed more conveniently and stably.

Abstract: An image forming apparatus and control method which use an intermediate transfer medium to transfer an image developed on an organic photoconductive medium onto a paper, and clean a surface of the intermediate transfer medium using a cleaning blade are provided. The apparatus and control method comprise driving the organic photoconductive medium and the intermediate transfer medium together with each other during a warming-up mode; stopping the organic photoconductive medium and the intermediate transfer medium until a print command is input during a stand-by mode; printing the developed image onto the paper sheet using the intermediate transfer medium in response to the print command; and reducing a friction between the intermediate transfer medium and the cleaning blade.

Abstract: A device to prevent breakaway of a transfer belt and a transfer unit equipped with the same. A device to prevent breakaway includes rib members each provided along opposite longitudinal edges of the inner surface of the transfer belt, and guide members each provided at one of opposite ends of a roller of the transfer unit, in order to guide the rib members. Each of the guide members is provided with a guide projection that is in contact with one of the rib members.

Abstract: An apparatus and method of driving a transfer belt are disclosed. The apparatus and method comprise driving the transfer belt provided in an image forming apparatus by a predetermined distance when the transfer belt has been stopped for a predetermined time, and thus varying the contact portion with a plurality of rollers provided on the transfer belt. Image contamination due to deformation on the belt can be avoided. Additionally, because the rotation time of the driving source can be set to a predetermined time during the power-saving mode, power consumption can be minimized.

Abstract: An apparatus for discharging waste toner, including a housing temporarily storing waste toner separated from a surface of a photosensitive medium; a waste toner discharge port formed at a bottom of the housing; a shutter rotatably disposed at a side of the housing to open and cover the waste toner discharge port; a pinion gear to rotate the shutter; and a fixed gear, disposed on a frame to which the housing is mounted, engaging the pinion gear, the pinion gear rotating along the fixed gear when the housing is mounted to the frame, to rotate the shutter away from the waste toner discharge port. The shutter includes a latch to hold the shutter in place when the shutter covers the waste toner discharge port.

Abstract: In an electrostatic transfer type liquid electrophotographic printer, an applied pressure between each photosensitive drum and a first transfer roller corresponding to the photosensitive drum is reduced along a downstream of a traveling direction of a transfer belt to prevent the deterioration of a toner image generating due to the amount of a liquid carrier sequentially increased when toner image on the photosensitive drum for each color are transferred and overlapped onto the transfer belt.

Abstract: A waste toner collecting device of an electrophotographic printer is provided. The device includes a housing to temporarily hold waste toner removed from an image holding body, an exhaust guide member including an exhaust hole through which the waste toner is exhausted, an opening and closing unit to open and close the exhaust hole, an inlet guide member having an inlet path to connect the exhaust hole to an inlet of a waste toner collection tank, and an elastic member which elastically supports the inlet guide member so that a gap between the exhaust hole and an inlet side of the inlet path is closely maintained when the exhaust guide member ascends and descends.

Abstract: An transfer belt for use in an image forming apparatus that senses an initial printing position. The belt includes a PC alloy portion, protective tape, and an error prevention section. The PC alloy portion includes a position sensing hole extending therethrough and disposed proximate to an edge of the PC alloy portion. The PC alloy portion is usable to determine an initial printing position. The protective tape is attached to upper sides and lower sides of both edges of the PC alloy portion. The error prevention section is insertable into the position sensing hole and has a thickness substantially equivalent to the PC alloy located around the position sensing hole.

Abstract: An apparatus for discharging waste toner, including a housing temporarily storing waste toner separated from a surface of a photosensitive medium; a waste toner discharge port formed at a bottom of the housing; a shutter rotatably disposed at a side of the housing to open and cover the waste toner discharge port; a pinion gear to rotate the shutter; and a fixed gear, disposed on a frame to which the housing is mounted, engaging the pinion gear, the pinion gear rotating along the fixed gear when the housing is mounted to the frame, to rotate the shutter away from the waste toner discharge port. The shutter includes a latch to hold the shutter in place when the shutter covers the waste toner discharge port.

Abstract: A photoreceptive unit and transfer unit replacement system of a printer includes a door opening and closing an entrance formed above a portion where a photoreceptive unit and a transfer unit are installed in a main body of the printer. A first guide rail is provided at a frame of the main body to guide the photoreceptive unit which enters through the entrance and descends. A second guide rail is provided at the frame to guide the transfer unit which enters through the entrance and descends. A locking unit locks and unlocks the photoreceptive unit and the transfer unit according to an operation of opening and closing the door. Thus, since the operation of opening and closing the door are performed according to the operation of locking and unlocking the respective photoreceptive unit and transfer units, and the photoreceptive unit and transfer units pass through the entrance disposed above the units, a replacement process can be performed more conveniently and stably.

Abstract: In an electrostatic transfer type liquid electrophotographic printer, an applied pressure between each photosensitive drum and a first transfer roller corresponding to the photosensitive drum is reduced along a downstream of a traveling direction of a transfer belt to prevent the deterioration of a toner image generating due to the amount of a liquid carrier sequentially increased when toner image on the photosensitive drum for each color are transferred and overlapped onto the transfer belt.

Abstract: A paper separating apparatus of a printer includes a separating member installed to be adjacent to an exit side of the transfer roller and under a path along which the paper is discharged and fixedly coupled to a pair of bearing guides which rotatably support opposite ends of the transfer roller to be capable of pivoting by a predetermined angle together with the bearing guides, a guide roller installed at an upper surface of the separating member for guiding discharge of the paper, a pivot restricting mechanism for restricting the pivot angles of the separating member and the bearing guides, and an elastic force applying mechanism for applying an elastic force in one direction so that the separating member and the bearing guides can maintain regular positions.

Abstract: A pair of cleaning apparatuses for a liquid electrophotographic printer that can completely remove to residual toner from both a photo receptor belt and a transfer roller, respectively. Each cleaning apparatus is supplied with a liquid solvent used to dissolve toner remaining on the transfer roller and the photo receptor belt after a printing operation. Each of the pair of cleaning apparatuses can engage and disengage to and from the photo receptor belt and the transfer roller respectively upon user actuation or entry of a sheet of recording media into the electrophotographic printing apparatus. Each cleaning apparatus contains in rectangular felt material soaked with solvent positioned to mate with the surfaces of the photo receptor belt and the transfer roller.

Abstract: A paper separating apparatus of a printer includes a separating member installed to be adjacent to an exit side of the transfer roller and under a path along which the paper is discharged and fixedly coupled to a pair of bearing guides which rotatably support opposite ends of the transfer roller to be capable of pivoting by a predetermined angle together with the bearing guides, a guide roller installed at an upper surface of the separating member for guiding discharge of the paper, a pivot restricting mechanism for restricting the pivot angles of the separating member and the bearing guides, and an elastic force applying mechanism for applying an elastic force in one direction so that the separating member and the bearing guides can maintain regular positions.

Abstract: A transfer unit of an electrophotographic printer includes: a transfer roller and a fuser roller for transferring an image onto the paper. One of the two rollers has a shape having flared ends and a smaller diameter at the center portion thereof and the other roller has a core portion having a crowned shape mating with the shape of the flared roller and a deformable portion which is provided around the core portion so as to form a circumferential surface having a straight profile line, and which is deformable so that a uniform gap between the two rollers is formed.

Abstract: A roller separating apparatus for a laser printer having a transfer backup roller, a steering roller, and a driving roller around which a photoreceptor belt circulatingly travels. The roller separating apparatus includes a first frame on which the transfer backup roller is rotatably installed. First and second eccentric cams are mounted for rotation on the first frame. A transfer roller is rotatably installed on a second frame which moves with respect to the first frame via engagement with a cam surface of the first eccentric cam. A fusing roller is rotatably installed on a third frame which moves with respect to the second frame via engagement with a cam surface of the second eccentric cam.