Ricoh Company, Ltd.

Sony Corporation

Jun Yamane

Masahide Yamashita

Osamu Satoh

Tetsuo Watanabe

Satoshi Kaneko

Takeshi Watanabe

Takashi Hashimoto

Yasushi Nakazato

Kohji Ue

Koichi Kudo

Hiromichi Matsuda

Katsuaki Miyawaki

Hideyuki Takayama

Shuji Hirai

Shinji Kato

Shingo Suzuki

Mikiko Imazeki

Hirofumi Shimizu

Shinobu Nakamura

Mamoru Kudo

Satoru Ooshima

Atsuyuki Oyamada

Hitoshi Ishibashi

Toshihiro Okamoto

Masaichi Sawada

Takenori Oku

Hitoshi Shimizu

Masato Kobayashi

Yasuo Suzuki

Nobuyuki Satoh

Ryota Yamashina

Daisaku Horikawa

Hiroki Uchiyama

Akihiro Sugino

Yoshiaki Kawasaki

Kimiharu Yamazaki

Takahisa Koike

Tatsuhiko Okada

Takaaki Ikegami

Minoru Takahashi

Hideo Nakamori

Michio Kimura

Norikazu Taki

Daisuke Sawada

Akira Takehisa

Shintaroh Takahashi

Daiki Sekita

Shokichiro Hino

Takafumi Seki

Noriyuki Ochiai

Yosushi Nakazato

A sheet conveying device, which is incorporated in an image forming apparatus, includes a first detector to detect an angle deviation of a recording medium to a sheet conveying direction, a second detector to detect a lateral shift of the recording medium to a width direction, a third detector to detect at least one of the angle deviation and the lateral shift after correction of the angle deviation detected by the first detector and the lateral shift detected by the second detector, and a rotary body to perform a primary movement by (1) rotating in the sheet conveying direction and returning to a reference position and by (2) moving in the width direction and returning to the reference position, and a secondary movement by performing at least one of (1) and (2) after the primary movement.

Sheet conveying device and image forming apparatus incorporating the sheet conveying device

A sheet conveying device, which is included in an image forming apparatus and a post processing device, includes multiple position detectors and a position corrector. The multiple position detectors are aligned along a sheet conveying direction and configured to detect a side end of a sheet. The position corrector is configured to convey the sheet and correct a position of the sheet based on a positional deviation amount of the sheet, obtained by a detection result of the multiple position detectors. The positional deviation amount of the sheet is obtained by an extreme downstream position detector in the sheet conveying direction, of the multiple position detectors. A position of a subsequent sheet is corrected based on a sum of the positional deviation amount of the sheet and a positional deviation amount of the subsequent sheet.

Sheet conveying device, image forming apparatus incorporating the sheet conveying device, and post processing device incorporating the sheet conveying device

A sheet conveying device, which is included in an image forming apparatus, includes a sheet holding roller to move while holding a sheet, a detector to perform a primary detection to detect a sheet position before the sheet holding roller holds the sheet and a secondary detection to detect a sheet position downstream from the sheet position detected by the primary detection, and a controller configured to cause the sheet holding roller to perform a first drive to move the sheet holding roller in at least one direction of a width direction of the sheet and a rotation direction in a sheet conveying surface based on a result of the primary detection and a second drive to move the sheet holding roller opposite to the at least one direction of the first drive, based on a result of the secondary detection.

A sheet conveying device, which is included in an image forming apparatus, includes a detector to detect a lateral end face of a sheet, a first pair of rollers to hold and convey the sheet and swing in a direction parallel to a plane of the sheet, a second pair of rollers to convey the sheet together with the first pair of rollers, and a controller to rotate the first pair of rollers to multiple angles, detect time changes at each angle at the lateral end face while conveying the sheet, and determine a home position corresponding to a position where respective rates of the time changes of the sheet at the first and second nip regions are substantially identical to each other or a home position having a least difference of rates of the time changes of the sheet at the first and second nip regions.

A sheet conveying device, which is included in an image forming apparatus and a post processing device, includes a position corrector and either one of a rolling body and a contact resistance reducer. The position corrector is configured to convey a sheet and correct a position of the sheet. The rolling body is disposed at least one of an upstream side and a downstream side of a sheet conveyance passage from the position corrector in a sheet conveying direction and is configured to roll in at least a direction intersecting the sheet conveying direction. The contact resistance reducer is configured to reduce contact resistance generated due to contact of the sheet to a neighboring part when the position of the sheet is corrected by the position corrector.

An image reading device, which is included in an image forming apparatus and used to perform a method of reading images, includes an image reading body configured to read one of a recording medium and the recording medium together with a background area adjacent to the recording medium, a moving body disposed facing the image reading body, and a reference body as a reference in shading correction. The moving body is configured to hold the recording medium and the reference body in a direction intersecting a sheet conveying direction of the recording medium such that the recording medium and the reference body contact to and separate from the image reading body.

Image reading device, image forming apparatus and method using the image reading device employing movable guide plate holding the medium and shading correction plate

A transfer device includes a belt image bearer; a driving roller that rotates the belt image bearer; a transfer member; first and second driving motors that respectively rotate the driving roller and the transfer member; first and second speed detecting units that respectively detect rotational speeds of the belt image bearer and the transfer member; and a control unit that implements control such that the belt image bearer and the transfer member are rotated at rotational speeds corresponding to a relative speed at which a variation amount is less than a predetermined variation amount, the variation amount being the variation of values of driving torques of the first and second driving motors in a state where the belt image bearer and the transfer member are in contact, with respect to these values in a state where the belt image bearer and the transfer member are separated.

Transfer device and image forming apparatus

An image forming apparatus includes an image carrier; a developer carrier configured to adhere toner onto the image carrier; an image density detector to detect a density of an image on the image carrier formed by the developer carrier adhering the toner on the image carrier; a rotary member to form an image pattern of which density is detected by the image density detector; and a rotational position detector to detect a rotational position of the rotary member. In the image forming apparatus, the image pattern is generated based on the rotational position detected by the rotational position detector and the rotary member that the rotational position detector detects the rotational position thereof is either the image carrier or the developer carrier.

Image forming apparatus and image forming method

In an image forming apparatus, a processor generates a first density variation data based on the surface potential of the pattern in relation to the rotational position of the image bearer and a second density variation data based on the first density variation data and the density of the toner pattern, stores the first density variation data and the second density variation data in a memory, makes a pattern in a predetermined timing, decides whether the first density variation data is changed or not, change the first density variation data based on the decision, controls the toner image forming condition of the toner image forming device based on the first density variation data and the second density variation data.

Image forming apparatus capable of reducing image density irregularity

An image forming apparatus includes an image carrier; an image forming unit; a processor for controlling the image forming unit according to a predetermined image forming condition setting data; an image density sensor to detect an image density of the toner pattern formed on the image carrier; a reference rotary position detector; an image density fluctuation data acquisition unit to obtain an image density fluctuation data of more than one circumferential length of the photoreceptor drum with reference to the reference rotary position detected by the reference rotary position detector based on a result related to the toner pattern formed on the image carrier detected by the image density sensor; and a correction data generator to generate a correction data to correct a reference image forming condition setting data with a correction amount corresponding to each rotary position of the rotary member to thus reduce the image density fluctuation.

Image forming apparatus

In an image forming apparatus, a first controller forms a first image pattern on an image bearer and determines a first image formation condition based on a detection result of density of a toner image. The first controller then controls a toner image forming device based on the first image formation condition. A second controller forms a second image pattern different from the first image pattern on an image bearer and determines a second image formation condition based on a detection result of density of a toner image. The second controller then controls a toner image forming device based on the second image formation condition.

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Kanagawa, Japan

Jun Yamane