Ricoh Company, Ltd.

Tetsuo Yamanaka

Hiroshi Hosokawa

Eisaku Murakami

Toshihiro Sugiyama

Kazuhiro Yuasa

Satoru Komatsubara

Hiroshi Saitoh

Yoshiaki Tanaka

Eiji Takenaka

Iwao Matsumae

Shuichi Endoh

Mugijiroh Uno

Kazuhiko Kobayashi

Tadashi Shinohara

Jun Hosokawa

Hiroyasu Shijo

Mineyo Takahashi

Yuzo Katsumata

Yasushi Nakazato

Masahiro Yonekawa

Nahoko Aizawa

Kenetsu Osanai

Hiroyuki Takahashi

Nekka Matsuura

Kouta Fujimori

Hiroyuki Shibaki

Kenichirou Nagai

Motonori Hanada

Moriaki Ogawa

Masaharu Iida

Mugijiro Uno

Yuzoh Katsumata

Eizi Takenaka

Mugiziroh Uno

Konosuke Maruyama

Kenichiroh Nagai

An image forming apparatus includes a replaceable image formation unit. The image forming apparatus includes an input device for inputting a signal representing occurrence of abnormality in one of an output image and the image forming apparatus recognized by an operator, a unit specifying device for specifying an image formation unit to be replaced for resolving the abnormality upon receiving the signal, and a notification device for notifying information related to the replacement unit based on the unit specification result.

Image forming apparatus and control system

An image forming apparatus including a plurality of detachable image forming devices each configured to form a color image, an image carrying device configured to carry the color images sequentially overlaid into a single color image, an exchange detecting device configured to detect an exchange operation of the plurality of detachable image forming devices, a test pattern reading device configured to read a predetermined test pattern formed by the plurality of detachable image forming devices on the image carrying device, and a controller configured to instruct 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 operation, and to perform a color image position adjustment based on readings of the predetermined test pattern by the test pattern reading device.

Method and apparatus for image forming capable of effectively performing color image position adjustment

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 east during an image forming process, a slip condition is substantially the same throughout all image transfer positions where the image carriers face the members.

Image forming apparatus including controller driving image carriers

A color image forming apparatus including a plurality of image forming devices, a transfer device including a transfer belt, a test pattern forming device configured to form, on the transfer belt, a test pattern including a plurality of marks formed by the image forming devices, an optical sensor configured to read the plurality of marks, and a checking device configured to determine whether reading by the optical sensor is performed correctly or not.

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.

A color image forming apparatus including a plurality of image forming devices attachable to and detachable from a housing, a transfer device including a transfer belt, an exchange detecting device configured to detect exchange of the image forming devices, a test pattern forming device configured to form, on the transfer belt, a test pattern including a plurality of marks formed by the image forming devices, when the exchange detecting device detects an exchange of the image forming device, an optical sensor configured to read the plurality of marks, and a checking device configured to determine whether reading by the optical sensor is performed correctly or not.

An image forming apparatus of the present invention includes image carriers arranged side by side in a preselected direction, developing mechanisms configured to form 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.

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 image forming devices, a test pattern reading device for reading a predetermined test pattern formed by the image forming devices on the image carrying device, and a controller configured to instruct the image forming devices to form the predetermined test pattern when either the detecting device detects the exchange, the fixing temperature is lower than a predetermined temperature, a color print adjustment command is provided, or the total number of color prints is greater than that at the last color print adjustment, and to perform color image position adjustment based on readings of the predetermined test pattern by the test pattern reading device.

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 vof the transfer belt in a period between formation of the mark pattern and the detection of the mark pattern, and a moving speed vduring image formation. A speed difference calculating unit calculates a speed difference &#x394;v=v&#x2212;v, and a control unit controls a timing of forming an image based on the interval difference and the value of &#x394;v so as to reduce position misalignment.

Color image forming apparatus, tandem type color image forming apparatus, and process cartridge for color image forming apparatus

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.

Color offset detecting apparatus and method

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.

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.

Image forming apparatus including driving means disposed downstream of nip

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.

Method and apparatus for image forming capable of effectively performing color displacement detection

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.

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Tokyo, Japan

Tetsuo Yamanaka