Ricoh Company, Ltd.

Ricoh Printing Systems, Ltd.

Hitachi Koki Co., Ltd.

Shingo Takai

Satoshi Ueda

Makoto Nakura

Naoto Ueda

Koichi Kudo

Yasushi Hashimoto

Akira Kobashi

Kazuhiko Kawasaki

Tatsuo Matsuda

Takuro Kamiya

Masaru Kawamoto

Yuichiro Maeyama

Yutaka Shoji

Hiroshi Suzuki

Toshihiro Nakagaki

Tomohiko Saito

Youichi Takeuchi

Noboru Hirano

Dai Kurabayashi

Yohei Sakon

Michihiro Matsuda

A printing apparatus includes a printing device to print, on a sheet, a detection mark for acquiring an amount of deviation of an image, a detection device to read a position of the detection mark and acquire the amount of deviation of the position of the detection mark, and control circuitry to perform correction according to the amount of deviation. The circuitry prints the detection marks on both faces of the sheet in duplex printing, reads the detection marks on both faces with the detection device, calculates a first correction value from the position of the detection mark on a first face on which printing is performed first, calculates a second correction value from the position of the detection mark on a second face on which printing is performed later, and calculates a third correction value from the positions of the detection marks on the first and second faces.

Printing apparatus

An image forming apparatus includes an image forming unit forming an image on a first recording medium based on image data, a measurement unit being positioned in an immediate vicinity of the image forming unit, being arranged upstream of a sheet-conveyance path than the image forming unit, and measuring a size of the first recording medium, an expansion ratio calculation unit calculating an expansion ratio of the first recording medium based on a first size of the first recording medium obtained before the first recording medium is passed through the image forming unit and a second size of the first recording medium obtained after the first recording medium is passed through the image forming unit, and a correction unit correcting the image data used for forming another image on a second recording medium conveyed after the first recording medium based on the expansion ratio.

Image forming apparatus, image forming method, and computer-readable recording medium

An image forming apparatus includes an image forming unit that forms an image on a recording medium; a width detector that detects positions of side edges of the recording medium in a width direction, which is orthogonal to a conveying direction in which the recording medium is conveyed, at multiple detection positions along the conveying direction; a shape calculator that calculates angles between the conveying direction and straight lines each connecting the positions of the same side edge detected at the multiple detection positions and calculates a shape of the recording medium based on the angles; and a correction unit that corrects image data of the image to be formed by the image forming unit based on the calculated shape of the recording medium.

Image forming apparatus for calculating shape of recording medium based on angles between conveying direction and straight lines using upstream and downstream detectors

An image forming apparatus includes an image forming unit to form an image on a recording medium; an inverting transport unit to invert first and second surfaces of the recording medium, and front and rear ends of the recording medium to transport the inverted recording medium; a recording medium width measuring unit to measure an end position of the recording medium in a width direction orthogonal to a transporting direction of the recording medium at a measuring position having an approximately identical distance from one end of the recording medium in the transporting direction before and after the image is formed on the recording medium; and a correcting unit to correct an image to be formed on a subsequent recording medium based on a change in a shape of the recording medium computed based on a measured result from the recording medium width measuring unit.

Image forming apparatus for improving accuracy in alignment of an image to be printed on two surfaces of a recording medium by measuring a size of the recording medium

A cooling device includes: a cooling roller that cools down a sheet-like member by coming into contact with the sheet-like member; a belt member that is rotatably extended by a plurality of extending members, presses the sheet-like member against the cooling roller, and holds and carries the sheet-like member; and a driving roller that serves as one of the plurality of extending members and drives to rotate the belt member, wherein the driving roller is axially divided into a plurality of rollers and each of the plurality of rollers has a crown-like shape whose outer diameter continuously becomes larger from both end parts to a center part in an axial direction.

Cooling device and image forming apparatus

A sheet conveying apparatus includes a sheet conveying unit that conveys a sheet including a drive roller, a driven roller, and a rotary encoder provided on a rotational axle of one of the drive roller and the driven roller; a conveying amount measuring unit that measures a conveying amount of the sheet; a first detection unit positioned downstream of the sheet conveying unit, the first detection unit being positioned apart from the drive roller and the driven roller not to overlap with the drive roller and the driven roller in the conveying direction; a second detection unit positioned upstream of the sheet conveying unit; and a conveying distance calculation unit that calculates a conveying distance of the sheet based on the measured result by the conveying amount measuring unit and the detected results detected by the first detection unit and the second detection unit.

Sheet conveying apparatus, image forming apparatus, sheet conveying distance calculation apparatus and sheet length calculation apparatus

A sheet conveying apparatus includes a sheet conveying unit including a drive roller and a driven roller; a downstream detection unit and an upstream detection unit; a conveying amount measuring unit that measures a conveying amount of the sheet; and a conveying distance calculation unit that calculates a conveying distance of the sheet, wherein a distance between the downstream detection unit and the upstream detection unit or a perimeter of one of the drive roller and the driven roller is set such that an expected conveying distance calculated based on a set sheet length of an expected value of the sheet becomes a substantially integer multiple of a perimeter of the one of the drive roller and the driven roller.

Sheet conveying apparatus and image forming apparatus

A disclosed sheet carrying device includes a first carrying unit that includes a first rotary body, a first driving unit outputting a driving force at a first peripheral speed, a one-way clutch transmitting the driving force only in a sheet carrying direction, and a second rotary body driven by the first rotary body via the sheet; and a second carrying unit including a third rotary body rotating at a second peripheral speed being the first peripheral speed or more, a fourth rotary body carrying the sheet with the third rotary body, a second driving unit outputting a driving force for driving the fourth rotary body at a third peripheral speed being the second peripheral speed or more, and a torque limiter having a slip torque smaller than a sheet carrying torque and cutting off the driving force while the sheet is interposed between the third and fourth rotary bodies.

Sheet carrying device and image forming apparatus

Disclosed is a device for correcting an edge portion of a sheet material, including a first roller provided in a sheet material conveying path, a second roller including a center shaft and side rollers provided at both sides thereof, the center shaft having an outer diameter less than a minimum diameter of the side rollers, each of the side rollers having an outer diameter increasing from a center side to an outer side thereof, and a pressing unit configured to cause the second roller to bend toward the first roller to press the side rollers of the second roller against the first roller.

Device for correcting an edge portion of a sheet material and electrophotographic image forming apparatus

A sheet conveying apparatus includes a sheet conveying unit that conveys a sheet; a conveying amount measuring unit that measures a conveying amount of the sheet conveyed by the sheet conveying unit; a first detection unit that detects the sheet downstream of the sheet conveying unit in a conveying direction of the sheet; a second detection unit that detects the sheet upstream of the sheet conveying unit in the conveying direction of the sheet; and a conveying distance calculation unit that calculates a conveying distance of the sheet based on the measured result by the conveying amount measuring unit and the detected results detected by the first detection unit and the second detection unit.

A sheet length measuring device includes a rotating body configured to rotate with a movement of a sheet in a conveying direction; a position detecting unit configured to detect leading and trailing ends of the sheet passing through a position of the rotating body; a measuring unit configured to measure a rotation amount of the rotating body and output an origin signal per one revolution of the rotating body; a storage unit configured to store changes of a sheet conveying amount with respect to respective rotation angles in one revolution of the rotating body; and a calculating unit configured to calculate a corrected length of the sheet from a value obtained from a rotation angle of the rotating body when the leading end of the sheet is detected and a value obtained from a rotation angle of the rotating body when the trailing end of the sheet is detected.

Sheet length measuring device and image forming apparatus

A sheet conveying apparatus including: a sheet conveying unit; an upstream side guiding member that forms an upstream side conveying route of a sheet; a downstream side guiding member that forms a downstream side conveying route of the sheet; an upstream side detection unit; and a downstream side detection unit, wherein a detection position of the sheet for the upstream side detection unit is set between the sheet conveying unit and a position where the sheet is in contact with the upstream side guiding member, and a detection position of the sheet for the downstream side detection unit is set between the sheet conveying unit and a position where the sheet is in contact with the downstream side guiding member.

A sheet-supplying device has a sheet-accommodating tray, a raising/lowering unit, a first position sensor, a second position sensor, a controlling unit. The raising/lowering unit raises and lowers the sheet-accommodating tray substantially. The first position sensor detects a first position indicating a position in the stacked direction of one end portion of a topmost sheet stacked in the sheet-accommodating tray. The second position sensor detects a second position indicating a position in the stacked direction of another end portion of the topmost sheet. The controlling unit controls the raising/lowering unit to raise or lower the sheet-accommodating tray based on both the first position detected by the first position sensor and the second position detected by the second position sensor so that one end of the topmost sheet in the stacked status is positioned at a prescribed position in the stacked direction.

Sheet-supplying device

A disclosed photoconductive drum includes a mechanism where, when the sleeve inner circumferential surface pressing member is in contact with the inner circumferential surface of the photoconductive sleeve member, a displacement of the first end surface member with respect to the photoconductive sleeve member in the center line direction leads to increasing a pressing force applied from the sleeve inner circumferential surface pressing member to the inner circumferential surface of the photoconductive sleeve member.

Growing community of inventors

Ibaraki, Japan

Shingo Takai