Ricoh Company, Ltd.

Yoshio Miyamoto

Akito Yoshimaru

Atsuo Tokunaga

Shigeru Morinaga

Yuichiro Maeyama

Satoshi Hirata

Kikuya Nakada

Yusuke Harasawa

Kentaro Uehara

A sheet conveyance unit for transporting a sheet unreeled from a roll of paper includes a roll holder including a pair of supporters to support both axial end portions of the roll, movable in an axial direction of the roll, a pair of first conveyance rollers, a pair of second conveyance rollers, a tensioner to tension the sheet, disposed between the first conveyance rollers and the second conveyance rollers, and a tension adjustment unit. The tensioner includes a contact plate to press against the sheet, extending over an entire width of the sheet and pivotably supported on a casing of the sheet conveyance unit. The tension adjustment unit changes the tension of the sheet by adjusting a force to press the contact plate against the sheet and includes a first adjuster to change the tension of the sheet in conjunction with the interval between the supporters.

Sheet conveyance unit and image forming apparatus including same

A sheet feeder for transporting a sheet unreeled from a roll includes a feed roller to unreel the sheet from the roll, a registration roller to transport the sheet unreeled by the feed roller to the image forming unit, a pressure roller pressing against the registration roller, forming a registration nip together with the registration roller, a movable sheet guide to guide the sheet to the registration roller, disposed between the feed roller and the registration roller in a sheet conveyance path, a support member to movably support the movable sheet guide relative to an apparatus body in which the sheet feeder is disposed, and a bias member to bias the sheet guide toward the sheet. The movable sheet guide wraps more of the sheet around the registration roller as a degree of tension of the sheet increases by moving against a bias force exerted by the bias member.

Sheet feeder and image forming apparatus including same

A roll-sheet feeding device having a roll sheet wound in a roll to feed a portion of the roll sheet to an image forming unit, includes a progressive mechanism to transmit a drive force from a drive source to transfer the portion of the roll sheet from the roll in a progressive direction, a roll-sheet drive mechanism to receive the drive force transmitted via the portion of the roll sheet transferred in the progressive direction, a rewinding mechanism to transfer the portion of the roll sheet in a direction opposite to the progressive direction via the roll-sheet drive mechanism to rewind the roll sheet, and a regenerating mechanism to obtain the drive force from the roll-sheet drive mechanism and transmit the obtained drive force to the progressive mechanism to regenerate the transmitted drive force as another drive force in addition to the drive force from the drive source.

Roll-sheet feeding device and image forming apparatus

In a recording medium transporting mechanism, a flange member is attached on either side of a roll paper and the flange member has a diameter smaller than a maximum outer diameter of a roll paper. Support rollers support a corresponding one of the flange members in a rotatable manner. The support rollers are moveable along the axis of rotation of the roll paper. The sum of an outer diameter of corresponding one of the flange members and the support rollers is greater than a maximum outer diameter of the roll paper. A rewinding roller of at least a length equivalent to a distance between both sets of support rollers when the sets of support rollers are farthest apart is engaged with a support roller within the set of support rollers and can rotate the flange member in a rewinding direction over a desired amount of continuous time.

Growing community of inventors

Kanagawa, Japan

Yoshio Miyamoto