Ricoh Company, Ltd.

Sony Corporation

Atsushi Nagata

Takashi Seto

Yuuji Wada

Hiromitsu Takagaki

Naoto Kochi

Shinya Tanaka

Kenji Sugiura

Hirokazu Ishii

Takashi Fujita

Takehide Mizutani

Keigo Nakamura

Ryo Hasegawa

Haruki Nagata

Kazuya Saito

Kazumi Suzuki

Naohiro Kumagai

Junpei Fujita

Seiichi Kogure

Kazuki Yogosawa

Shin Kayahara

Takahiro Suzuki

Keisuke Kubota

Takeshi Takemoto

Kenji Honjoh

Hiroki Nakamatsu

Takashi Kagami

Takeshi Yamamoto

Daisuke Ito

Toshio Koike

Daisuke Takahashi

Naomi Sugimoto

Akio Kosuge

Yuji Kato

Yasufumi Takahashi

Kazuosa Kuma

Akihiro Kikuchi

Takeshi Fukao

Osamu Ichihashi

Takafumi Abe

Shinichi Akatsu

Takahiro Konishi

Kazuhiko Shimizu

Tsutomu Kato

Toshiharu Hachisuka

Masakazu Imai

Yusuke Mitani

Teruyuki Miyakawa

Yoshinori Tanba

Takayuki Isawa

Tatsuo Imai

Haruo Iwasaki

Hiroto Okochi

An image forming apparatus includes an image bearer, a nip former, a transfer bias supply, and processing circuitry. The nip former to form a transfer nip between the image bearer and the nip former. The transfer bias supply applies a transfer bias in which an alternating current component is superimposed on a direct current component to the transfer nip, to transfer a toner image onto a transfer target object at the transfer nip. The processing circuitry is to execute a processing mode of determining the DC component and the AC component to be used in a print job, based on a plurality of test toner images transferred to the transfer target object under transfer conditions different from each other in combination of the DC component and the AC component while changing the DC component and the AC component.

Image forming apparatus

There is provided a consumable supply method for supplying a refill consumable stored in a refill consumable container to a consumable container installable in an equipment body. The consumable supply method includes removing a refill information storage device storing information on the refill consumable from the refill consumable container; removing an information storage device storing information on a consumable contained in the consumable container, the information being for exchange with the equipment body, from the consumable container; and attaching the refill information storage device removed from the refill consumable container as an information storage device to the consumable container in place of the information storage device removed from the consumable container.

Consumable supply method, consumable container, image forming apparatus, and refill consumable container

An image forming apparatus includes a latent image bearer, a toner image forming unit, an intermediate transfer member, a primary transfer member, a secondary transfer member, a switching unit, and control circuitry. The toner image forming unit forms toner images on the latent image bearer. The primary transfer member transfers the toner images on the latent image bearer onto the intermediate transfer member. The secondary transfer member transfers the toner images on the intermediate transfer member onto recording materials. The switching unit switches a position of one of the secondary transfer member and the intermediate transfer member between a first and a second position. The control circuitry controls at least one of a first and a second operation. The control circuitry changes at least one of the first and the second operation when the toner images satisfy a specified abnormal image reduction condition at a first and a second timing.

A cam drive device includes a cam to rotate; a displacement body to be displaced in response to a change in a rotation position of the cam in contact with the displacement body; a motor to rotate the cam; and a power source to output an electric current to be supplied to the motor. An electric current to cause a stall torque to the motor being a stop state is changed in response to a change in a rotation stop position of the cam.

Cam drive device and image forming apparatus incorporating same

An image forming apparatus including an image bearer, a transfer-bias power source, an environment sensor, and a controller. The controller controls the transfer-bias power source to change the DC component and the AC component, according to the at least one of temperature and humidity detected by the environment sensor and a duty of the transfer bias. The duty is A/(A+B)&#xd7;100[%] where A denotes an area on a return-directional side to move toner from the recording sheet back to the image bearer, relative to a center value (Voff) of a maximum value and a minimum value of the transfer bias in one cycle of a waveform of the transfer bias, and B denotes an area on a transfer-directional side to move the toner from the image bearer to the recording sheet, relative to the center value (Voff) in the one cycle.

An improved image forming apparatus includes an image bearer, a nip forming member, a transfer power source, and a controller. The controller switches a transfer mode between a first mode to transfer the toner image onto a first type sheet having a surface smoothness higher than a surface smoothness of a second type sheet and a second mode to transfer the toner image onto the second type sheet. The controller controls the transfer power source to output the transfer bias having an opposite-peak duty of greater than or equal to 50% that is a duty on the side of the opposite-peak value in the first mode. The controller controls the transfer power source to output the transfer bias having an opposite-peak duty of less than 50%, which is different from the opposite-peak duty of the first mode, in the second mode.

Image forming apparatus and image forming method

An image forming apparatus includes an apparatus body, a plurality of image bearers, an endless belt, a contact and separation mechanism to generate a first trajectory and a second trajectory of the endless belt, a sensor to detect an object on a surface of the endless belt, and a positioning mechanism to enable the sensor to detect the object in the first trajectory and the second trajectory of the endless belt. The positioning mechanism includes a stay to support the sensor, a first bracket, a second bracket, a first positioning portion attached to the apparatus body to position the sensor in a direction of rotation of the first bracket and the second bracket at a time of the first trajectory, and a second positioning portion attached to the second bracket to position the sensor in the direction of rotation of the first bracket at a time of the second trajectory.

An image forming apparatus includes an image bearer to bear a toner image, a nip forming member contacting the image bearer to form a transfer nip, and a transfer power source. The transfer bias has a transfer peak value to electrostatically move toner from the image bearer to the recording sheet and an opposite-peak value to electrostatically move less toner from the image bearer to the recording sheet than the transfer peak value. An opposite-peak duty of the transfer bias is less than 50%. The opposite-peak duty is tr/T&#xd7;100% where T is one cycle of the transfer bias and tr is a time period during which the transfer bias is on a side of the opposite-peak value relative to an offset voltage of the transfer bias in the one cycle T.

Image forming apparatus and image forming method for controlling a secondary transfer bias according to recording sheet type

An image forming apparatus including an image bearer; a nip forming member, a nip width changing device, a power source; and a controller. The controller switches between a first mode and a second mode according to a predetermined condition. In the first mode, a duty of the transfer bias is a first duty and a width of a transfer nip is a first width. In the second mode, the duty of the transfer bias is a second duty lower than the first duty and the width of the transfer nip is a second width greater than the first width. The duty is (T&#x2212;Tt)/T&#xd7;100% where T denotes one cycle of the transfer bias, and Tt denotes a time period, in which the transfer bias is on a transfer-directional side relative to a time-averaged value of the transfer bias, in the one cycle.

An image forming apparatus includes an image bearer, an image forming device to form a toner image on the image bearer with toner, a power source to output a bias to transfer the toner image onto a recording medium, and control circuitry. The circuitry controls the power source to decrease a peak-to-peak voltage of the bias in response to increase in at least one of temperature and humidity, when a time-averaged voltage of the bias is on a transfer side of transferring the toner to the recording medium, from a median value of maximum and minimum voltages of the bias. The circuitry controls the power source to increase the peak-to-peak voltage of the bias in response to increase in at least one of temperature and humidity, when the time-averaged voltage of the bias is on a return side of returning the toner to the image bearer, from the median value.

An image forming apparatus includes a plurality of image forming units, a plurality of image bearers, a transfer device, and a controller. The image forming units form a process color toner image and a special color toner image. The transfer device transfers the process color toner image and the special color toner image from the image bearers onto the intermediate transfer member. The controller is configured to correct a transfer bias applied to transfer the special color toner image onto the intermediate transfer member. The controller is configured to decrease the bias in a special color mode in which image formation is performed with only a special color and increase the bias in a full color mode in which image formation is performed with the special color and a process color, according to a degree of degradation of a developer used to form the special color toner image.

Transfer device and image forming apparatus incorporating same

An image forming apparatus includes an image bearer to bear a visible image, a transfer device to transfer the visible image from the image bearer onto a recording medium, a separator to separate the recording medium from the image bearer, a separation bias application device to apply a separation bias to the separator; and a controller to control the separation bias. When the recording medium fed in the image forming apparatus is either a black sheet or a metallic sheet, the controller sets the separation bias smaller than a predetermined separation bias value for a reference sheet type other than the black sheet and the metallic sheet.

Image forming apparatus and method of separating recording medium

An image forming apparatus includes an image bearer, a nip forming device, a contact-and-separation device, a thickness information retrieving device, and a controller. The contact-and-separation device moves the image bearer and the nip forming device to contact and separate from each other. The controller controls the contact-and-separation device based on information on a thickness of a recording medium obtained by the thickness information retrieving device such that in a case in which a thickness of a preceding recording medium and a thickness of a successive recording medium are different in continuous printing in which a plurality of recording media is printed out continuously, the contact-and-separation device adjusts a space between the image bearer and the nip forming device when the preceding recording medium exits the transfer nip to a preset size corresponding to the thickness of the successive recording medium that enters the transfer nip.

An image forming apparatus includes an image carrier that carries a toner image; a transfer member that forms a transfer nip between the transfer member and the image carrier; and a power supply capable of outputting a superimposed transfer bias in which an alternating current component is superimposed onto a direct current component. The toner image on the image carrier is transferred onto a recording medium in the transfer nip by the superimposed transfer bias or a direct current bias consisting of the direct current component output by the power supply. The apparatus also includes a controller that controls the power supply so that an output target value of the direct current component when the direct current component rises up is larger than an output target value of the direct current component when the toner image is transferred onto the recording medium.

An image forming apparatus includes an image bearer; a toner image forming unit, a transfer unit, a detector, and a controller. The toner image forming unit forms a plurality of types of density detection patterns on the surface of the image bearer in mutually-different positions in a surface-movement direction of the image bearer. The density detection patterns have mutually-different lengths in a direction orthogonal to the surface-movement direction of the image bearer. The transfer unit transfers the density detection patterns onto the surface of the transfer member. The detector detects image densities of the density detection patterns transferred on the surface of the transfer member. The controller calculates an image density difference between the density detection patterns on a basis of a detection result obtained by the detector, and corrects a transfer bias for transferring a toner image on a basis of a value of the image density difference.

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Kanagawa, Japan

Atsushi Nagata