Abstract: A fuser of an electrophotographic image forming apparatus fuses a toner image to a recording medium by applying heat and pressure. The fuser includes first and second rollers that are elastically biased against each other and that rotate while facing each other. An elastic layer is provided on at least one of the first and second rollers, and a heat source is provided on at least one of the first and second rollers. A gear is coupled to an end portion of at least one of the first and second rollers. First and second interval maintenance members are respectively coupled to the first and second rollers at the end portions of the rollers which are opposite to the end portion where the gear is coupled. The first and second maintenance members face each other and contact each other to regulate an amount of compression of the elastic layer.

Abstract: A fixing unit and an image forming apparatus using the same. The fixing unit includes: a pair of fixing rollers that rotate and face each other and apply heat and pressure to a toner image transferred to the sheet of paper using electrophotography; a plurality of guide members disposed in the width direction of the sheet of paper to guide the sheet of paper discharged from the pair of fixing rollers to the discharge path, each of the guide members including a first guiding portion extending toward the discharge path from an outlet of the pair of fixing rollers; a first arm rotatably installed between the guide membersthat elastically contact the sheet of paper drawn out of the pair of fixing rollers and guide the sheet of paper to the discharge path; and an elastic member elastically biasing the first arm such that the first arm contacts the sheet of paper, wherein a guide member adjacent to the first arm has a second guide portion that is shorter than the first guide portion.

Abstract: A fusing unit used with a color laser printer includes a pair of rollers which heat and press a sheet of paper, onto which an image is transferred, and fuse the transferred image on the sheet of paper, and plastic mold bearings which rotatably support the rollers to be centered on frames.

Abstract: A fusing apparatus and method for an image forming apparatus comprise a housing, a first roller mounted in the housing, a second roller rotated in contact with the first roller, a heater movably mounted in at least one of the first and the second rollers and comprising a first heater and a second heater, a first power supplying terminal and a second power supplying terminal movably supported in the housing, and a pair of connection units movably supported in the housing to connect the respective heater terminals to the corresponding power supplying terminals. The power supplying terminals and the connection units have a predetermined gap with an outer surface of the housing, such that when the housing expands in a lengthwise or horizontal direction of the heater, the outer surface of the housing tightly contacts with at least one of the heater terminals, the power supplying terminals and the connection units, thereby fixing or securing the heater in the housing.

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: A paper guide which does not make stripes on an image on a printing paper. The paper guide of an electrophotographic image forming apparatus includes a guiding member for guiding the printing paper into a fusing unit, a plurality of guiding ribs formed on the guiding member to prevent direct contact of the printing paper with the guiding member, and a blocking bar formed on a leading end near the fusing unit of the guiding member in order that the spaces between the plurality of guiding ribs are blocked from the fusing unit. The blocking bar is formed at the same height as the guiding ribs and has a triangular section with a slope steeper than the section of the guiding ribs.

Abstract: A bearing structure reduces friction between a roller and a bearing under a pressure. A fusing device for an image forming apparatus employs the bearing structure. The bearing structure installed between a frame and a rotary shaft supports the rotary shaft on the frame. A bearing body has a fitting part in which the rotary shaft is rotatably fitted. A rolling support unit is installed on at least one portion inside the fitting part to contact the rotary shaft in a rolling manner. The fusing device includes a fusing roller in which a heater is embedded, and a pressure roller that faces the fusing roller and cooperates with the fusing roller in pressing a sheet of paper passing therebetween. Bearing structures rotatably support the fusing roller and the pressure roller on a frame. Each bearing structure includes a bearing body having a fitting part, and a rolling support unit installed on at least one area inside the fitting part to contact the fitted roller in a rolling manner.

Abstract: A fusing apparatus and method for an image forming apparatus comprise a housing, a first roller mounted in the housing, a second roller rotated in contact with the first roller, a heater movably mounted in at least one of the first and the second rollers and comprising a first heater and a second heater, a first power supplying terminal and a second power supplying terminal movably supported in the housing, and a pair of connection units movably supported in the housing to connect the respective heater terminals to the corresponding power supplying terminals. The power supplying terminals and the connection units have a predetermined gap with an outer surface of the housing, such that when the housing expands in a lengthwise or horizontal direction of the heater, the outer surface of the housing tightly contacts with at least one of the heater terminals, the power supplying terminals and the connection units, thereby fixing or securing the heater in the housing.

Abstract: A paper guide which does not make stripes on an image on a printing paper. The paper guide of an electrophotographic image forming apparatus includes a guiding member for guiding the printing paper into a fusing unit, a plurality of guiding ribs formed on the guiding member to prevent direct contact of the printing paper with the guiding member, and a blocking bar formed on a leading end near the fusing unit of the guiding member in order that the spaces between the plurality of guiding ribs are blocked from the fusing unit. The blocking bar is formed at the same height as the guiding ribs and has a triangular section with a slope steeper than the section of the guiding ribs.

Abstract: A fixing unit and an image forming apparatus using the same. The fixing unit includes: a pair of fixing rollers that rotate and face each other and apply heat and pressure to a toner image transferred to the sheet of paper using electrophotography; a plurality of guide members disposed in the width direction of the sheet of paper to guide the sheet of paper discharged from the pair of fixing rollers to the discharge path, each of the guide members including a first guiding portion extending toward the discharge path from an outlet of the pair of fixing rollers; a first arm rotatably installed between the guide membersthat elastically contact the sheet of paper drawn out of the pair of fixing rollers and guide the sheet of paper to the discharge path; and an elastic member elastically biasing the first arm such that the first arm contacts the sheet of paper, wherein a guide member adjacent to the first arm has a second guide portion that is shorter than the first guide portion.

Abstract: A fusing unit used with a color laser printer includes a pair of rollers which heat and press a sheet of paper, onto which an image is transferred, and fuse the transferred image on the sheet of paper, and plastic mold bearings which rotatably support the rollers to be centered on frames.

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: A paper guide which does not make stripes on an image on a printing paper. The paper guide of an electrophotographic image forming apparatus includes a guiding member for guiding the printing paper into a fusing unit, a plurality of guiding ribs formed on the guiding member to prevent direct contact of the printing paper with the guiding member, and a blocking bar formed on a leading end near the fusing unit of the guiding member in order that the spaces between the plurality of guiding ribs are blocked from the fusing unit. The blocking bar is formed at the same height as the guiding ribs and has a triangular section with a slope steeper than the section of the guiding ribs.

Abstract: An image forming apparatus including a printing unit which prints an image on paper, an exit path which connects an exit of the printing unit to an exit member which pushes the paper outside of the printing unit, a plurality of guide members which are arranged widthwise of the paper, each guide member having a first guide side which guides the paper coming out of the printing unit along the exit path, wherein each guide member is installed to be movable such that the first guide side rotates when the first guide side contacts the paper which comes out of the printing unit, and returns to its original position after the paper completely passes through the printing unit.

Abstract: An apparatus to switch a paper feed direction for an image forming device includes a paper guide part disposed across a paper feed path to move from an initial position to a paper passing position or a paper jam removing position by a force generated by passing of the paper, or external power; a supporting part to rotatably fix the paper guide part to a frame of the office machine; an elastic restoring part to restore the paper guide part from the paper jam removing position to the paper passing position; and a restoring force blocking part to block a force of the elastic restoring part from acting on the paper guide part until the paper guide part fixed to the supporting part rotates beyond the paper passing position.

Abstract: A multi-function actuator of a duplex printer selects one of movement passages of a printing medium according to whether to print one side or on both sides of the printing medium and includes a duplex guide, a jam removing mechanism, a sensor arm, and a sensor. The duplex guide is rotatable disposed above a pressure roller of a duplex printer frame and includes a hollow cylinder and a plurality of bar-shaped guide pins at one side thereof guiding the printing medium. The jam removing mechanism is rotatable disposed inside of the hollow cylinder to allow the pressure roller to be separated from the heat roller when a jammed material is removed. The with arm is disposed co-axially with the duplex guide and rotates by a weight thereof. The sensor is disposed at the duplex printer frame and operates by the sensor arm. Accordingly, the multi-function actuator selects the one of the movement passage and allows the jammed material to be removed by separating the pressure roller from the heat roller.

Abstract: A multi-function actuator of a duplex printer selects one of movement passages of a printing medium according to whether to print one side or on both sides of the printing medium and includes a duplex guide, a jam removing mechanism, a sensor arm, and a sensor. The duplex guide is rotatably disposed above a pressure roller of a duplex printer frame and includes a hollow cylinder and a plurality of bar-shaped guide pins at one side thereof guiding the printing medium. The jam removing mechanism is rotatably disposed inside of the hollow cylinder to allow the pressure roller to be separated from the heat roller when a jammed material is removed. The sensor arm is disposed co-axially with the duplex guide and rotates by a weight thereof. The sensor is disposed at the duplex printer frame and operates by the sensor arm. Accordingly, the multi-function actuator selects the one of the movement passage and allows the jammed material to be removed by separating the pressure roller from the heat roller.

Abstract: A fixing temperature controlling process in an image forming apparatus. The resistance of a transfer roller is detected upon request of a fixing temperature control. It is determined which of fixing environment conditions set according to changes in fixing performance caused by environmental change the resistance belongs to. An optimal fixing temperature is detected for the determined fixing environment condition and the temperature of a fixer is controlled to the detected optimal fixing temperature.