Abstract: A mark pattern forming unit forms a mark pattern on a transfer belt, and a reflection type optical sensor detects the mark pattern. An interval difference acquiring unit acquires an interval difference that is a deviation of each mark from a reference position. A speed detector detects a moving speed v1 of the transfer belt in a period between formation of the mark pattern and the detection of the mark pattern, and a moving speed v2 during image formation. A speed difference calculating unit calculates a speed difference ?v=v1?v2, and a control unit controls a timing of forming an image based on the interval difference and the value of ?v so as to reduce position misalignment.

Abstract: An apparatus for forming a plurality of different color visual images on a photosensitive member is provided. A transfer medium driven by a driving roller and receives the plurality of different color visual images at a transfer section from the photosensitive member. The transfer medium superimposes and transfers the different color visual images to a transfer sheet a plurality of mark sets each formed from a set of different color marks (Bk, Y, M, C) aligned in a movement direction is formed on the transfer medium. Respective marks are detected by a sensor. An average of displacements of respective different color marks from a reference position is then calculated. The sensor is positioned being distanced from the transfer section by a prescribed length. The prescribed length is calculated by multiplying a conveyance length the transfer medium travels when the driving roller rotates once by an integer number.

Abstract: An image forming apparatus including a plurality of detachable image forming devices each for forming a color image, an image carrying device for carrying the color images sequentially overlaid into a single color image, an exchange detecting device for detecting an exchange of the plurality of detachable image forming devices, a test pattern reading device for reading a predetermined test pattern formed by the plurality of detachable image forming devices on the image carrying device, and a controller for instructing the plurality of detachable image forming devices to form the predetermined test pattern on the image carrying device when the exchange detecting device detects the exchange and perform a color image position adjustment based on readings of the predetermined test pattern by the test pattern reading device.

Abstract: Low-hygroscopicity low-birefringence resin compositions. One of the compositions is a resin composition (a) comprising the following polymers (A), and (B) and/or (C). Another is a resin composition (b) comprising the following polymers (A), (B) and (H). Still another is a polymer comprising the following polymers (I) and (J), diphenylsilicone (D), and a phenolic antioxidant (E). (A) A polymer comprising one or more kinds of indene and indene derivatives represented by the following general formula (I). (B) A polymer comprising polystyrene or a polystyrene derivative. (C) A polymer comprising a monomer copolymerizable with styrene or a styrene derivative. (H) A graft polymer having a structure wherein a polymer comprising at least one kind of indene and an indene derivative represented by the general formula (I) bonds to a side chain of a polymer comprising a monomer copolymerizable with styrene or a styrene derivative.

Abstract: An image forming apparatus of the present invention includes an image carrier whose surface is movable in a preselected direction while carrying a toner image thereon. A movable body has a surface movable in the same direction as the image carrier in contact with the image carrier, thereby forming a nip. A drive member exerts a force that pulls a portion of the movable body contacting the image carrier out of the nip. An image transfer unit transfers the toner image from the image carrier to the movable body at the nip. A controller controllably drives the image carrier and movable body such that the movable body starts moving after the image carrier. The apparatus not only reduces the image forming time, but also frees images from disfigurement ascribable to the slack of the movable body.

Abstract: A method of color displacement detection for use in a color image forming apparatus sequentially forming image layers in different colors on a photosensitive member and overlaying the image layers on one after another into a color image on a transferring member. This method includes steps of forming, detecting, and calculating. The forming step forms a predetermined number of mark sets within one circumferential length surface of the transferring member. Each of the predetermined number of mark sets includes a predetermined number of different color marks arranged in a line in a moving direction of the transferring member. The detecting step detects the predetermined number of mark sets formed on the transfer member. The calculating step calculates mean values of displacement amounts of same color marks in different mark sets in the predetermined number of mark sets relative to respectively corresponding reference positions.

Abstract: Low-hygroscopicity low-birefringence resin compositions. One of the compositions is a resin composition (a) comprising the following polymers (A), and (B) and/or (C). Another is a resin composition (b) comprising the following polymers (A), (B) and (H). Still another is a polymer comprising the following polymers (I) and (J), diphenylsilicone (D), and a phenolic antioxidant (E). (A) A polymer comprising one or more kinds of indene and indene derivatives represented by the following general formula (I). (B) A polymer comprising polystyrene or a polystyrene derivative. (C) A polymer comprising a monomer copolymerizable with styrene or a styrene derivative. (H) A graft polymer having a structure wherein a polymer comprising at least one kind of indene and an indene derivative represented by the general formula (I) bonds to a side chain of a polymer comprising a monomer copolymerizable with styrene or a styrene derivative.

Abstract: An image forming apparatus including a plurality of detachable image forming devices each for forming a color image, an image carrying device for carrying the color images sequentially overlaid into a single color image, an exchange detecting device for detecting an exchange of the plurality of detachable image forming devices, a test pattern reading device for reading a predetermined test pattern formed by the plurality of detachable image forming devices on the image carrying device, and a controller for instructing the plurality of detachable image forming devices to form the predetermined test pattern on the image carrying device when the exchange detecting device detects the exchange and perform a color image position adjustment based on readings of the predetermined test pattern by the test pattern reading device.

Abstract: An image forming apparatus of the present invention includes an image carrier whose surface is movable in a preselected direction while carrying a toner image thereon. A movable body has a surface movable in the same direction as the image carrier in contact with the image carrier, thereby forming a nip. A drive member exerts a force that pulls a portion of the movable body contacting the image carrier out of the nip. An image transfer unit transfers the toner image from the image carrier to the movable body at the nip. A controller controllably drives the image carrier and movable body such that the movable body starts moving after the image carrier. The apparatus not only reduces the image forming time, but also frees images from disfigurement ascribable to the slack of the movable body.

Abstract: A mark pattern forming unit forms a mark pattern on a transfer belt, and a reflection type optical sensor detects the mark pattern. An interval difference acquiring unit acquires an interval difference that is a deviation of each mark from a reference position. A speed detector detects a moving speed v1 of the transfer belt in a period between formation of the mark pattern and the detection of the mark pattern, and a moving speed v2 during image formation. A speed difference calculating unit calculates a speed difference &Dgr;v=v1−v2, and a control unit controls a timing of forming an image based on the interval difference and the value of &Dgr;v so as to reduce position misalignment.

Abstract: A method of image forming that employs detachable image forming mechanisms for forming color images, each individually using a color toner different from each other and an image carrying member for carrying the color images that are sequentially overlaid on one another into a single color image. A detecting step detects the exchange of one of the detachable image forming mechanisms. A further step performs an adjustment for eliminating displacements of color images formed by the detachable image forming mechanisms, in accordance with the detection of the exchange of one of the detachable image forming mechanisms detected in the detecting step.

Abstract: An image forming apparatus of the present invention includes an image carrier whose surface is movable in a preselected direction while carrying a toner image thereon. A movable body has a surface movable in the same direction as the image carrier in contact with the image carrier, thereby forming a nip. A drive member exerts a force that pulls a portion of the movable body contacting the image carrier out of the nip. An image transfer unit transfers the toner image from the image carrier to the movable body at the nip. A controller controllably drives the image carrier and movable body such that the movable body starts moving after the image carrier. The apparatus not only reduces the image forming time, but also frees images from disfigurement ascribable to the slack of the movable body.

Abstract: An apparatus for forming a plurality of different color visual images on a photosensitive member is provided. A transfer medium driven by a driving roller and receives the plurality of different color visual images at a transfer section from the photosensitive member. The transfer medium superimposes and transfers the different color visual images to a transfer sheet a plurality of mark sets each formed from a set of different color marks (Bk, Y, M, C) aligned in a movement direction is formed on the transfer medium. Respective marks are detected by a sensor. An average of displacements of respective different color marks from a reference position is then calculated. The sensor is positioned being distanced from the transfer section by a prescribed length. The prescribed length is calculated by multiplying a conveyance length the transfer medium travels when the driving roller rotates once by an integer number.

Abstract: An image forming apparatus of the present invention includes image carriers arranged side by side in a preselected direction, developing means each for forming a toner image on one of the image carriers, a drive mechanism for driving in the preselected direction a member to which toner images are to be sequentially transferred from the image carriers one above the other, and image transferring devices each for transferring a toner image from one of the image carriers to the above member. At least during an image forming process, a slip condition is substantially the same throughout all image transfer positions where the image carriers face the member.

Abstract: An image forming apparatus of the present invention includes an image carrier whose surface is movable in a preselected direction while carrying a toner image thereon. A movable body has a surface movable in the same direction as the image carrier in contact with the image carrier, thereby forming a nip. A drive, member exerts a force that pulls a portion of the movable body contacting the image carrier out of the nip. An image transfer unit transfers the toner image from the image carrier to the movable body at the nip. A controller controllably drives the image carrier and movable body such that the movable body starts moving after the image carrier. The apparatus not only reduces the image forming time, but also frees images from disfigurement ascribable to the slack of the movable body.

Abstract: A method of color displacement detection for use in a color image forming apparatus sequentially forming image layers in different colors on a photosensitive member and overlaying the image layers on one after another into a color image on a transferring member. This method includes steps of forming, detecting, and calculating. The forming step forms a predetermined number of mark sets within one circumferential length surface of the transferring member. Each of the predetermined number of mark sets includes a predetermined number of different color marks arranged in a line in a moving direction of the transferring member. The detecting step detects the predetermined number of mark sets formed on the transfer member. The calculating step calculates mean values of displacement amounts of same color marks in different mark sets in the predetermined number of mark sets relative to respectively corresponding reference positions.

Abstract: A method of image forming that employs detachable image forming mechanisms for forming color images, each individually using a color toner different from each other and an image carrying member for carrying the color images that are sequentially overlaid on one another into a single color image. A detecting step detects the exchange of one of the detachable image forming mechanisms. A further step performs an adjustment for eliminating displacements of color images formed by the detachable image forming mechanisms, in accordance with the detection of the exchange of one of the detachable image forming mechanisms detected in the detecting step.

Abstract: A developing device including a developing roller opposed to a photoconductor and rotatably mounted to a developing case of the developing device. A blade mounting surface is formed in an outer wall of the developing case, that is opposed to the photoconductor, and a blade holder, a blade and a supporting plate, that are laminated with each other, are mounted to the blade mounting surface of the developing case. A part of the blade opposite to a part of the blade sandwiched between the blade holder and the supporting member is elastically bent so as to contact an outer circumferential surface of the developing roller, and seal members are arranged at least along an edge of a longitudinal side of the blade holder at the side of the developing roller and along an edge of another longitudinal side of the blade holder at the opposite side of the developing roller, respectively, so as to increase airtightness of gaps between the blade holder and the outer wall of the developing case.

Abstract: A novel process cartridge for an image forming apparatus such as for example an electrophotographic copying machine, an image forming apparatus using the novel process cartridge, and a method of manufacturing the novel process cartridge. The cartridge includes a photoconductor unit in which a photoconductor drum is rotatably mounted and a developing unit in which a developing roller is rotatably mounted. A first pair of side plates are formed on the photoconductor unit and rotatably supports both end portions of the photoconductor drum. A second pair of side plates are formed on the developing unit and rotatably supports both end portions of the developing roller. A first pair of pin inserting holes are formed on the first pair of side plates of the photoconductor unit. A second pair of pin inserting holes are formed on the second pair of side plates of the developing unit.