Ricoh Company, Ltd.

Sony Corporation

Sony Mobile Communications Inc.

Sony Mobile Communications Japan, Inc.

Yuuji Wada

Kenji Sugiura

Junpei Fujita

Kazuki Yogosawa

Naohiro Kumagai

Seiichi Kogure

Takehide Mizutani

Hirokazu Ishii

Tatsuya Ohsugi

Hiroyoshi Haga

Yusuke Mitani

Naoto Kochi

Shinya Tanaka

Atsushi Nagata

Keigo Nakamura

Takahiro Suzuki

Toshitaka Yamaguchi

Jyunya Sakuraba

Naomi Sugimoto

Mitsuru Takahashi

Kenji Sengoku

Masayoshi Nakayama

Hiroaki Adachi

Hiroki Nakamatsu

Masahide Ishino

Kensuke Mashita

Mitsuyo Usami

Tomoko Takahashi

Daisuke Tomita

Hideki Kosugi

Toshihiro Hamamura

Ryo Hasegawa

Takaya Muraishi

Junichi Ichikawa

Yasunari Harada

Kunihiko Nishioka

Akihiko Adachi

Yasukazu Kitamura

Yu Yoneda

Kenji Sugirua

An image projection device includes a projector configured to project an image; and an operation unit configured to receive an operation performed by an operator. The projector is in a projecting state while the operation unit is receiving a pressing operation performed by the operator, and the projector is in a non-projecting state while the operation unit is not receiving a pressing operation performed by the operator.

Image projection device

A transfer device includes an intermediate transfer belt configured to bear a toner image and rotate, a transferor configured to contact the intermediate transfer belt via a recording medium and form a transfer nip, a guide configured to guide the recording medium conveyed to the transfer nip, and a pressure reducing device. The intermediate transfer belt is shaped as an endless belt. The pressure reducing device is configured to reduce pressure-contact force of the transferor against the intermediate transfer belt as the recording medium advances in the transfer nip. Therefore, a trailing end of the recording medium does not move toward the intermediate transfer belt when the trailing end of the recording medium has passed the guide.

Transfer 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.

Image forming apparatus

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 a belt-shaped image bearer, a transferer, a guide, two rotators, and a support. The image bearer has an image bearing surface to bear an image thereon. The transferer forms a transfer section between the transferer and the image bearer, to transfer the image onto a recording medium. The guide is disposed upstream from the transfer section in a delivery direction of the recording medium, to guide the recording medium toward the transfer section. The two rotators are disposed upstream from the transfer section in a moving direction of the image bearer and in contact with a non-image bearing surface of the image bearer opposite to the image bearing surface, a first rotator being closer to the transfer section than a second rotator. The support supports the first rotator and the guide and adjusts a position of the first rotator and a position of the guide.

Image forming apparatus with a support to adjust a rotator and a guide

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 includes an image bearer, an intermediate transferor, a secondary transferor, a plurality of rotators including a secondary driving rotator, and a detector. The image bearer bears a detection image. The detection image is transferred from the image bearer to the intermediate transferor at a primary transfer position. The secondary transferor is looped around the plurality of rotators and disposed in contact with the intermediate transferor at a secondary transfer position where the detection image is transferred from the intermediate transferor to the secondary transferor. The secondary driving rotator drives the secondary transferor. The detector detects the detection image on the secondary transferor at a detection position. With this configuration, a distance from the secondary transfer position to the detection position on the secondary transferor is an integral multiple of a circumference of the secondary driving rotator.

A belt device includes a belt unit including a plurality of rotators and a belt looped around the plurality of rotators. The belt device further includes a frame including a plurality of support portions to support the belt unit, a biasing member to bias the belt unit supported by the frame in a predetermined direction, and an adjuster to adjust a position of at least one of the plurality of support portions.

Belt device including support portions and an adjuster to adjust positions of the support portions

An image forming apparatus includes an image bearer including a first image portion to bear a first toner image, a second image portion to bear a second toner image, and a non-image portion to bear an adjustment pattern. A transferor forms a transfer nip with the image bearer. A controller controls the power source to output an image bias as a transfer bias to transfer the first toner image and the second toner image onto a first recording medium and a second recording medium, respectively, in the transfer nip when the first image portion and the second image portion pass through the transfer nip and output a non-image bias as the transfer bias when the non-image portion passes through the transfer nip. The controller performs a constant current control on the image bias and performs a constant voltage control when the image bias switches to the non-image bias.

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.

A belt unit is detachably attachable to a body of an image forming apparatus. The belt unit includes a belt, a pressing member, and a frame. The belt is wound around a plurality of supports to travel in a belt travel direction. The belt includes a base layer and an elastic layer. The pressing member presses warping on an edge of the belt. The frame supports the plurality of supports. The pressing member is positioned on the frame.

Belt unit, transfer unit, and image forming apparatus including a pressing member that presses an edge of a belt

An image forming apparatus includes an image bearer; a toner image forming device; an intermediate transferor; a primary transfer power source; a secondary transfer nip forming device; and a secondary transfer power source to output a secondary transfer bias. One of two peak values of the secondary transfer bias is a transfer peak value to provide a greater transfer-directional force to move toner from the intermediate transferor toward the recording medium in the secondary transfer nip. An absolute value of the transfer peak value is greater than an absolute value of the primary transfer bias.

Image forming apparatus and transfer bias control

An image forming apparatus includes a plurality of image bearers, a transfer bias member, and a power source. When the transfer bias member transfers a color toner image onto a recording sheet, a second peak value of a peak-to-peak of a transfer bias, which is smaller than a first peak value of the peak-to-peak in an electrostatic force to move toner from the image bearers or an intermediate transfer body to the recording sheet, is zero or has a first polarity to generate the electrostatic force in a transfer direction to move toner from the image bearers or the intermediate transfer body to the recording sheet. When the transfer bias member transfers a monochromatic toner image including only black toner onto the recording sheet, the second peak value is zero or has a second polarity to generate an electrostatic force in an opposite direction to the transfer direction.

An endless rotatable belt device including an endless rotatable belt, a scale tape bonded on the belt, at least one optical sensor to detect a scale pattern, and auxiliary tape to cover at least one of the first end and the second end of the scale tape of the belt. The scale tape has a first end and a second end and includes at least one scale pattern. The auxiliary tape has a lower surface friction coefficient than the surface friction coefficient of the scale tape.

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Kanagawa, Japan

Yuuji Wada