Ricoh Company, Ltd.

Osamu Ariizumi

Nobutaka Takeuchi

Naoto Watanabe

Shinji Kobayashi

Shinji Kato

Shin Hasegawa

Kayoko Tanaka

Hitoshi Ishibashi

Kohta Fujimori

Kazumi Kobayashi

Takashi Enami

Fukutoshi Uchida

Ryohta Morimoto

Yushi Hirayama

Tsukuru Kai

Shigekazu Enoki

Hisashi Shoji

Yasushi Koichi

Takeyoshi Sekine

Kumiko Hatakeyama

Koji Suzuki

Hajime Oyama

Toshiyuki Kabata

Masahide Yamashita

Nobuo Takami

Koichi Kato

Katsuhiro Aoki

Kei Yasutomi

Jun Yura

Yasuo Miyoshi

Takashi Hodoshima

Yuushi Hirayama

Shinichi Namekata

Hisao Kurosu

An image forming apparatus includes an image carrying member, an image forming mechanism, an optical sensor, and a controller. The image forming mechanism performs an image forming operation for forming a reference toner image on the image carrying member under a specific setting associated with the image forming mechanism. The optical sensor is arranged in a vicinity to the image carrying member. The controller performs an optical toner test for checking, by using the optical sensor, optical characteristics of the reference toner image formed on the image carrying member and to adjust the specific setting based on a result of the optical toner test.

Image forming apparatus capable of reducing a lengthy duration of an adjustment control

An image forming apparatus, which comprises a toner density detection device for detecting the density of a toner inside a developing device, acquires the number of pixels from inputted image information, calculates the toner replenishment amount from the toner density detection value and the information on the pixels, and thereby performs replenishment control so that excessive replenishment or insufficient replenishment of the toner is not caused. The upper limit value of the amount of toner to be replenished at once to the developing device is changed in accordance with the amount of information on an input image such as the image area, pixels of the input image.

Toner replenishment determination device of an image forming apparatus

In an image forming apparatus a developing device develops an electrostatic latent image on an image carrier with a developer that contains toner to obtain a toner image, a toner-amount detecting unit detects amount of toner attached to the toner image, and a toner-density detecting unit detects a density of toner in the developer. Moreover, a process control unit corrects a toner-density target value indicative of a target value of density of toner in the developer based on the amount of toner detected by the toner-amount detecting unit and the density of toner detected by the toner-density detecting unit, and a determines execution timing of next process based on corrected toner-density target value.

Image forming apparatus for correcting a toner density target value

A transfer residual toner that has not been electrostatically transferred onto a transfer paper P at a transfer nip and remains on a surface of a photosensitive element is temporarily retained by an elastic blade of a toner retaining unit in a mechanical manner before reaching a latent image forming area. When passing through the latent image forming area, the transfer residual toner is returned onto the surface of the photosensitive member at such a timing that writing is not performed by an exposing unit on the surface of the photosensitive element.

Image forming apparatus, process cartridge, cleaning system, and image forming apparatus with cleaning system

An image forming apparatus includes a plurality of image carriers, an image forming mechanism, a seamless belt-like intermediate transfer body or a transfer material carrier, a detection mechanism, and an optical detecting apparatus. The optical detecting apparatus includes at least a printed board, and a plurality of photodetectors formed of a light-emitting element, a light-receiving element and light-shielding members, which are mounted on the printed board. The optical detecting apparatus is disposed such that it detects a belt surface adjacent to rollers of the intermediate transfer body or the transfer material carrier, and either displacement of a transfer image or image density is detected by a plurality of photodetectors detecting pattern images which are transferred from the plurality of image carriers to the image transfer body or the transfer material carrier.

Method and apparatus for image forming capable of accurately detecting displacement of transfer images and image density

A developing unit supplies toner from a developing roller to an electrostatic latent image formed on an image carrier, and creates a visual image. A forced consumption unit causes, when a proportion of number of pixels used for forming the electrostatic latent image for a maximum image effective-width is equal to or less than a predetermined value, a forced consumption of toner by an amount corresponding to a difference between a toner amount corresponding to the number of pixels and a predetermined toner consumption amount. The forced consumption unit adds toner of an amount used in the forced consumption to an amount of toner to be supplied in a next imaging process.

Developing unit and image forming apparatus which forces consumption of toner

In an image forming apparatus, a toner image formed on a photosensitive drum is primarily transferred onto an intermediate transfer belt. The toner image on the intermediate transfer belt is secondarily transferred onto a transfer material by a secondary transfer roller in contact with the intermediate transfer belt. A relation A&#x3e;B&#x3e;C is satisfied, where A is a width of the intermediate transfer member, B is a width of the secondary transfer member, and C is a width of the transfer material. The intermediate transfer member includes a patch-pattern forming area that is not contacted by the secondary transfer member. The image forming apparatus includes a reflection-type photosensor that detects a patch pattern formed in the patch-pattern forming area.

Image forming apparatus and image forming method

An image forming apparatus includes at least one image bearing member, an intermediate transfer member, a secondary transfer member, and at least one optical sensor. In the image forming apparatus, it is determined that output values of the respective amounts of toner detected by the at least one optical sensor are affected by an impact caused due to a separation of the secondary transfer member from the intermediate transfer member and the output values are ignored as image adjustment input information, when the secondary transfer member separates from the intermediate transfer member during any of writing, developing, and transferring the plurality of image adjustment patterns, if the output values fall outside a given range and an interval between the output values of adjacent image bearing members is substantially equal to a distance between the two adjacent image bearing members for the primary transfer.

Image forming apparatus effectively conducting a process control

Image processing apparatus, process cartridge, and cleaning system with residual toner retaining unit

The image forming apparatus includes a developing device that holds a two-component developer to develop an image, a detecting unit that outputs a reference output value and a second output value when the two-component developer is stirred and carried at a stirring/carrying speed corresponding to a second image forming mode, a stirring/carrying member that stirs and carries the two-component developer, and a controlling unit that controls the toner concentration based on the reference output value when forming an image in a first image forming mode, and controls the toner concentration, when forming an image in the second image forming mode, a corrected output value obtained by correcting an output value in the second image forming mode with a difference value between the reference output value and the second output value.

Image forming apparatus and toner concentration controlling method

An image forming apparatus of includes a developing device bifunctioning as a cleaning device for collecting toner grains left on a photoconductive drum after the transfer of a toner image from the drum to a paper sheet or similar image transfer medium. In the event of toner collection, a DC voltage is applied that causes the residual toner to move from the drum toward a developing sleeve. A main-pole magnet generates, at a position where the developing sleeve faces the drum, a magnetic field of between 100 mT and 200 mT in a direction normal to the surface of the sleeve.

Image forming apparatus, process cartridge and cleaningless system

An image forming apparatus includes an image carrier, a charging device configured to uniformly charge a surface of the image carrier with a charging member applied with a bias of a first polarity (e.g. a negative polarity) for charging. A latent image forming device forms a latent image on the surface of the image carrier uniformly charged. A developing device develops a latent image by depositing toner grains of the first polarity on the latent image to thereby form a corresponding toner image. A transferring device forms an electric field between the image carrier and a moving member that serves as a movable contact with the image carrier to thereby transfer the toner image from the surface of the image carrier to the moving member or to a recording member nipped between the image carrier and the moving member. A polarity controlling device sets residual toner to a second polarity (e.g. a positive polarity) opposite to the first polarity, before the residual toner left on the image carrier by the transferring device is conveyed to a corresponding position to the charging member.

Image forming apparatus controlling polarity of residual toner and process cartridge for use in the same

A two-component developer including toner and magnetic carriers is provided. The two-component developer is characterized in that when a development device including a developer bearing member bearing the two-component developer is operated under a development condition of an image forming apparatus using a quasi-photoconductor in which a 10 &#x3bc;m thick layer of tetrafluoroethylene resin is provided to a conductive material, the number of times of light emission occurring in a magnetic brush formed on the developer bearing member due to partial conduction in the magnetic brush is 10 times or less per second at an observation cross section that is perpendicular relative to a rotation axis of the developer bearing member.

Magnetic carrier, two-component developer, development method, development device and image forming apparatus of electrophotography

An image forming apparatus of the present invention includes a bias power supply for applying a bias Vto a developer carrier on which a developer is deposited. A charge potential deposited on an image carrier, which faces the developer carrier for forming a latent image thereon, is 400 V or below in absolute value. Assume that the potential of the image carrier is lowered to Vafter exposure, that a development potential is |V&#x2212;V|, that the maximum set value of the development potential for development is |V&#x2212;V|max, and that the development potential varies in a range satisfying relations:||max+||max&#xd7;0.2||max&#x2212;||max&#xd7;0.2||max&#x2266;300 VThen image density varies by a width of 10% of image density corresponding to the maximum set value of the development potential or less.

Image forming apparatus

An image forming apparatus of the present invention includes a lubricator for applying a lubricant to an image carrier or a process unit around the image carrier to thereby reduce friction. The apparatus of the present invention insures a uniform halftone image, prevents the trailing edge of an image from being lost, and faithfully reproduces even a horizontal line.

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Kanagawa, Japan

Osamu Ariizumi