Ricoh Company, Ltd.

Nobutaka Takeuchi

Kohta Fujimori

Shin Hasegawa

Kayoko Tanaka

Yushi Hirayama

Hitoshi Ishibashi

Shinji Kato

Kazumi Kobayashi

Takashi Enami

Akira Yoshida

Takayuki Koike

Naoto Watanabe

Satoshi Muramatsu

Osamu Ariizumi

Junichi Matsumoto

Nobuo Iwata

Shinji Kobayashi

Tsukuru Kai

Kei Yasutomi

Hisashi Shoji

Fukutoshi Uchida

Ryohta Morimoto

Hirokatsu Suzuki

Yoshiaki Miyashita

Eriko Maruyama

Shuji Hirai

Kentaroh Tomita

Kiichirou Shimizu

Hajime Oyama

Nekka Matsuura

Masahiko Shakuto

Hiromitsu Takagaki

Tetsuya Muto

Toshihiko Baba

Takeyoshi Sekine

Yuushi Hirayama

Akio Kosuge

Ichiro Kadota

Satoru Komatsubara

Eichi Koizumi

Atsushi Shinozaki

Kazumi Suzuki

Hidetoshi Yano

Nobuo Takami

Naomi Sugimoto

Kenzo Tatsumi

Hiroshi Ikuno

Takeroh Kurenuma

Takashi Hodoshima

Hiroyuki Uenishi

Shinichi Akatsu

Keiichi Yoshida

Kouta Fujimori

Takahiko Tokumasu

Yuuichiroh Uematsu

Tomohide Takenaka

Keita Sone

Yukio Tabata

Yuji Hirayama

Keita Gotoh

Kazufumi Kimura

Motohiro Usami

Teiichiro Takano

Chiemi Hirano

Kiichiro Shimizu

An image forming apparatus includes an endless belt-shaped image bearer that is rotatably supported and entrained around rollers; a transfer member positioned to contact an outer surface of the image bearer; a transfer device to transfer a toner image conveyed while being carried on the outer surface of the image bearer onto a transfer medium conveyed between the image bearer and the transfer member; a toner image sensor to detect the toner image transferred onto the transfer medium; and a conveyance speed controller to fine-tune a conveyance speed of the transfer medium. Based on fine-tuning data of the conveyance speed controller, a detection result of the toner image sensor is corrected and image forming conditions are corrected based on the corrected detection result.

Toner pattern density correction in an image forming apparatus

An image forming apparatus includes an image information acquisition unit that acquires image information; a toner image formation unit that forms, in response to a control parameter, a toner image on a surface of an image carrier based on the image information; an image density detection unit that produces a detection result indicative of image density of the toner image; and a control unit that determines whether to use a predetermined region in the toner image formed on the surface of the image carrier based on the image information for a detection of the image density of the toner image, and when the predetermined region is determined to be used for the detection of the image density, corrects the control parameter used by the toner image formation unit based on the detection result so as to maintain the image density in the predetermined region within a predetermined range.

Image forming apparatus that performs parameter correction processing according to an image density in a predetermined region

An optical sensor attached to an apparatus includes a substrate and a light emitting element mounted on a first surface of the substrate. The light emitting element emits a light to a detection object in parallel to the substrate. A light receiving element is mounted on the first surface of the substrate. The light receiving element receives a regular reflection light reflected by the detection object. The said first surface serves as a positioning reference for positioning the optical sensor on an optical sensor mounting member provided in the apparatus.

Optical sensor with positioning reference surface and image forming apparatus incorporating optical sensor

An image forming apparatus includes a developer unit to store two-component developer which includes toner and carrier and develop an electrostatic latent image formed on the image carrier, a toner concentration detector to detect toner concentration in the developer unit, a toner supply unit to supply toner to the developer unit, and a controller to control toner supply amount by controlling the toner supply unit by comparing an output value of the toner concentration detector with a reference value stored in a memory and correcting difference between output values of the toner concentration detector at two or more process linear velocities in accordance with the toner concentration in the developer unit. A compensation amount for correcting difference between output values of the toner concentration detector that differ depending on the process linear velocity is adjustable in accordance with the toner concentration in the development unit.

Image forming apparatus and method for controlling image density

An optical sensor includes: a light-emitting unit; a light-receiving unit that receives light radiated from the light-emitting unit and reflected from a detection target and that outputs an output value in response to the light received; and a correcting unit that corrects the output value of the light-receiving unit when receiving the light reflected from the detection target based on the output value of the light-receiving unit obtained by irradiating a detection area of the optical sensor with light without any light reflective objects being present in the detection area.

Optical sensor and image forming apparatus

A supply control unit is configured to, in a successive image-forming operation, perform a process of successively generating a driving control pattern for a toner supply device based on image information of each page, and synthesizing an unused portion of the driving control pattern which is obtained by eliminating a portion of the driving control pattern already reflected on a driving control of the toner supply device from the driving control pattern generated based on image information of a previous page with a driving control pattern generated based on a subsequent page.

Supply control unit and image forming apparatus

A first developer container having a toner supplying opening is provided in a developing unit. A toner concentration sensor is arranged downstream of the toner supplying opening to detect toner concentration in developer. A supply controlling unit is provided to determine an excess or a shortage in the amount of supplied toner based on image information correspondingly to a detection result by the toner concentration sensor, and to correct the driving amount of a toner supplying unit that has been determined based on the image information correspondingly to the recognized excess or shortage in the amount of supplied toner.

Image forming apparatus including developing unit and toner supplying unit

An image forming apparatus forms a plurality of tone patterns of different colors, each of which containing a plurality of toner patches having different toner densities. Some of the toner patches in each of the tone patterns are formed with a predetermined fixed developing bias and the rest of the toner patches in each of the tone patterns are formed with developing biases set based on previous developing biases that have been obtained through a previous control process. The largest toner density of the toner patches in each of the tone patterns is determined based on a magnitude relation of previous index values obtained through the previous control process.

Image forming apparatus and image-density control method

An image forming apparatus of the present invention includes a developing unit for developing a latent image formed on an image carrier with a two-ingredient type developer, i.e., a toner and carrier mixture. A toner replenishing device replenishes toner stored in a toner storing portion to the developing unit. A carrier storing portion, storing a carrier therein, is constructed independently of the toner storing portion. The carrier is fed from the carrier storing portion to the developing unit by a toner conveying force available with the toner replenishing device.

Image forming apparatus including a developer replenishing device which uses an air feeding device for a two-ingredient type developer

An image forming apparatus is disclosed that includes an image density control unit that performs control operations based on an image density control condition that is adjustably set to control an output image to have a predetermined image density, an image density control condition modifying unit that calculates a modified image density control condition based on information on an amount of toner exchanged at a developing apparatus within a predetermined period and a parameter for image density control condition calculation and sets the modified image density control condition as the image density control condition to be used by the image density control unit, and a parameter modifying unit that modifies the parameter for image density control condition calculation used by the image density control condition modifying unit based on a toner pattern detection result obtained by detecting a toner pattern formed on a belt member.

Image forming apparatus and image density control method

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

A process cartridge for use in an image forming apparatus includes an image bearing member and a developing unit. The developing unit includes a developer bearing member to bear developer including toner and carrier, a casing forming a developer container containing the developer, a screw having a shaft with a spiral screw blade, a toner density sensor to detect a density of the toner on a detection surface, and a detection surface agitating member fixedly mounted on the shaft of the screw at a position facing a detection surface to scrape away the developer accumulated on the detection surface as the screw rotates. The detection surface agitating member includes an elastic sheet elastically deformable to scrape away the developer accumulated on the detection surface and disposed at a substantially same angle to an axial direction of the shaft of the screw as the spiral screw blade.

Process cartridge including developing unit and incorporated in image forming apparatus

An image forming apparatus includes an image carrier configured to carry an image and a charger to which a direct current voltage overlapped with an AC voltage is applied as a charging bias to charge the image carrier. The charger is positioned in contact or contactlessly with the image carrier. The AC voltage applied to the charger in an adjustment of the AC voltage is not less than twice a charging start voltage Vth at which the image carrier starts to be charged.

Image forming apparatus and method of adjusting charge bias

An image forming apparatus includes multiple image forming units to form different single-color images with respective different color developers and a control system to selectively perform a multicolor image forming operation, a specific-color image forming operation, a multicolor image quality correction operation, and a specific-color image quality correction operation. The control system includes an image formation mode detection unit to ascertain which of the multicolor image forming operation and the specific-color image forming operation is performed prior to a request for image quality correction; and a correction instruction unit to order the multicolor image quality correction operation when the multicolor image quality correction operation is requested, the specific-color correction operation when the specific-color image quality correction operation is requested after the specific-color image forming operation, and the multicolor image quality correction operation when the specific-color image quality correction operation is requested after the multicolor image forming operation.

Image forming apparatus and image quality correction method used therein

An image forming apparatus includes an image forming unit configured to form a plurality of toner images on an image carrier, an optical detector configured to detect reflection light from the toner image, and dedicated to detect infrared rays and near-infrared rays, and a controller configured to perform a predetermined control using a detection results of the optical detector. Gradation pattern that is comprised of a plurality of toner patches formed in the image forming unit with an image forming condition to have different adhesive amounts, and is formed of at least two colors, and detection values detected by the optical detector are used for the predetermined control.

Image forming apparatus capable of efficient toner concentration control

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Kanagawa, Japan

Nobutaka Takeuchi