Abstract: A color registration apparatus that independently forms images of predetermined respective colors and compensates a mis-registration between the overlapped images of respective colors employed in an image forming apparatus of forming a color image by overlapping the images of respective colors, includes a detecting unit to detect a contour form and positional information of respective color patterns formed on an image transfer path by the image forming apparatus proportional to a corresponding format of a printing medium where the color image will be transferred, and a controller to compensate a mis-registration between the overlapped images of respective colors through based on data detected by the detecting unit.

Abstract: An image forming apparatus includes a display unit which outputs image data in the form of a complete image, a photosensitive medium which forms an electrostatic latent image corresponding to the image outputted from the display unit, a developing unit which develops the electrostatic latent image formed on the photosensitive medium, a transfer unit which transfers the developed image of the photosensitive medium onto a printing medium, and a fixing unit which fixes the transferred developed image in the printing medium.

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, an electro-photographic image forming apparatus having the same, and a printing method thereof are provided. The electro-photographic image forming apparatus includes a printing unit that forms a toner image on a recording medium by an electro-photographic method, a heat roller, a first pressure roller that faces the heat roller and forms a first fixing nip therebetween, one or more second pressure rollers that face the heat roller and form a second fixing nip therebetween, and a guide member that changes its position to a first position for guiding the recoding medium to the second fixing nip after the recording medium passes through the first fixing nip or to a second position for blocking the recording medium from moving to the second fixing nip after the recording medium passes through the first fixing nip.

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: Provided is a paper detection apparatus for detecting the size of a sheet of paper transferred along a paper transfer path, which includes a light source and an optical sensor. A plurality of light emitting optical fibers are located at a first side of the paper transfer path and receive light radiated by the light source and emit the received light to a plurality of positions in a widthwise direction of the paper. A plurality of light receiving optical fibers are located at a second side of the paper transfer path and guide the light emitted by the light emitting optical fibers toward the optical sensor. A determination unit detects the size of the paper based on the amount of light detected by the optical sensor.

Abstract: An image forming apparatus has a plurality of image bearing bodies in a predetermined sequence, an intermediate transfer medium for running in contact with each of the plurality of image bearing bodies, and a plurality of supporting rollers for driving the intermediate transfer medium. A distance between points of contact of at least two image bearing bodies on the intermediate transfer medium is a positive integer multiple of the length of circumference of one of the supporting rollers.

Abstract: A medium detecting device to detect information corresponding to a printing medium fed through a medium transport path, includes a detecting unit to detect a contour form information of the printing medium; and a discriminating unit to determine a format of the printing medium and feeding information based on the contour form information of the printing medium detected by the detecting unit.

Abstract: A color registration apparatus that independently forms images of predetermined respective colors and compensates a mis-registration between the overlapped images of respective colors employed in an image forming apparatus of forming a color image by overlapping the images of respective colors, includes a detecting unit to detect a contour form and positional information of respective color patterns formed on an image transfer path by the image forming apparatus proportional to a corresponding format of a printing medium where the color image will be transferred, and a controller to compensate a mis-registration between the overlapped images of respective colors through based on data detected by the detecting unit.

Abstract: An image forming apparatus has a plurality of image bearing bodies in a predetermined sequence, an intermediate transfer medium for running in contact with each of the plurality of image bearing bodies, and a plurality of supporting rollers for driving the intermediate transfer medium. At least two image bearing bodies are oriented such that radius deviations of the respective image bearing bodies are in substantial registration along the intermediate transfer medium.

Abstract: An image forming apparatus includes a display unit which outputs image data in the form of a complete image, a photosensitive medium which forms an electrostatic latent image corresponding to the image outputted from the display unit, a developing unit which develops the electrostatic latent image formed on the photosensitive medium, a transfer unit which transfers the developed image of the photosensitive medium onto a printing medium, and a fixing unit which fixes the transferred developed image in the printing medium.

Abstract: An image forming apparatus has a plurality of image bearing bodies in a predetermined sequence, an intermediate transfer medium for running in contact with each of the plurality of image bearing bodies, and a plurality of supporting rollers for driving the intermediate transfer medium. At least one image bearing body and at least one supporting roller are arranged such that a radius deviation of the image bearing body is in registration along a transfer medium with a radius deviation of the supporting roller.

Abstract: A fixing unit, an electro-photographic image forming apparatus having the same, and a printing method thereof are provided. The electro-photographic image forming apparatus includes a printing unit that forms a toner image on a recording medium by an electro-photographic method, a heat roller, a first pressure roller that faces the heat roller and forms a first fixing nip therebetween, one or more second pressure rollers that face the heat roller and form a second fixing nip therebetween, and a guide member that changes its position to a first position for guiding the recoding medium to the second fixing nip after the recording medium passes through the first fixing nip or to a second position for blocking the recording medium from moving to the second fixing nip after the recording medium passes through the first fixing nip.

Abstract: Provided is a paper detection apparatus for detecting the size of a sheet of paper transferred along a paper transfer path, which includes a light source and an optical sensor. A plurality of light emitting optical fibers are located at a first side of the paper transfer path and receive light radiated by the light source and emit the received light to a plurality of positions in a widthwise direction of the paper. A plurality of light receiving optical fibers are located at a second side of the paper transfer path and guide the light emitted by the light emitting optical fibers toward the optical sensor. A determination unit detects the size of the paper based on the amount of light detected by the optical sensor.

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 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: An image forming apparatus has a plurality of image bearing bodies in a predetermined sequence, an intermediate transfer medium for running in contact with each of the plurality of image bearing bodies, and a plurality of supporting rollers for driving the intermediate transfer medium. At least one image bearing body and at least one supporting roller are arranged such that a radius deviation of the image bearing body is in registration along a transfer medium with a radius deviation of the supporting roller.

Abstract: An image forming apparatus has a plurality of image bearing bodies in a predetermined sequence, an intermediate transfer medium for running in contact with each of the plurality of image bearing bodies, and a plurality of supporting rollers for driving the intermediate transfer medium. A distance between points of contact of at least two image bearing bodies on the intermediate transfer medium is a positive integer multiple of the length of circumference of one of the supporting rollers.

Abstract: An image forming apparatus has a plurality of image bearing bodies in a predetermined sequence, an intermediate transfer medium for running in contact with each of the plurality of image bearing bodies, and a plurality of supporting rollers for driving the intermediate transfer medium. The rollers are manufactured such that a driven coupler is engaged with the roller body in a predetermined orientation with a location of a radius deviation along the circumference of the roller body.

Abstract: An image forming apparatus has a plurality of image bearing bodies in a predetermined sequence, an intermediate transfer medium for running in contact with each of the plurality of image bearing bodies, and a plurality of supporting rollers for driving the intermediate transfer medium. At least two image bearing bodies are oriented such that radius deviations of the respective image bearing bodies are in substantial registration along the intermediate transfer medium.