Feeding device and feeding method, and image forming device

A paper transporting apparatus transporting continuous paper to a paper processing part that performs designated processing on the continuous paper, comprising:

• a drive roller that transports the continuous paper in a forward direction with respect to the paper Processing part and a direction opposite to the forward direction by a frictional force;
• a pre-centering mechanism, disposed upstream of the drive roller with respect to the forward direction, that regulates a position of the continuous paper with respect to a direction orthogonal to the forward direction and the backward direction by abutting against the continuous paper;
• and
• a tension increasing mechanism, disposed upstream of the pre-centering mechanism with respect to the forward direction, that increases tension on the continuous paper,
• wherein the pre-centering mechanism includes:
• a guide part that abuts against an edge of the continuous paper to regulate its position;
• and
• a skew roller, provided at a designated angle with respect to the guide part, that energizes the continuous paper so as to press the continuous paper against the guide part when the continuous paper is transported in the forward direction and the backward direction, the designated angle being set variable.

A paper transport method comprising the steps of:

• driving a drive roller that nips continuous paper together with plural driven rollers and transports the continuous paper to a paper processing part performing designated processing on the continuous paper by a frictional force in a forward direction and a direction opposite to the forward direction;
• increasing tension on the continuous paper when the continuous paper is transported via a tension increasing mechanism provided upstream of a pre-centering mechanism with respect to the forward direction, wherein the pre-centering mechanism is disposed upstream of the drive roller with respect to the forward direction and regulates the position of the continuous paper with respect to a direction orthogonal to the forward direction and the backward direction by abutting against the continuous paper;
• and
• controlling one of the driving step and the increasing step so that a relation of W>U>W/N holds, where W is a transport force by the drive roller, N is the number of the driven rollers, and U is a paper load force by the tension increasing mechanism.

A paper transport method comprising the steps of:

• driving a drive roller that nips continuous paper together with plural driven rollers and transports the continuous paper to a paper processing part performing designated processing on the continuous paper by a frictional force in a forward direction and a direction opposite to the forward direction;
• increasing tension on the continuous paper when the continuous paper is transported in the forward direction and the backward direction via a tension increasing mechanism provided upstream of a pre-centering mechanism with respect to the forward direction, wherein the pre-centering mechanism is disposed upstream of the drive roller with respect to the forward direction and regulates the position of the continuous paper with respect to a direction orthogonal to the forward direction and the backward direction by abutting against the continuous paper;
• and
• controlling one of the driving step and the increasing step so that a relation of W>U>W/N holds, where W is a transport force by the drive roller, N is the number of the driven rollers, and U is a paper load force by the tension increasing mechanism.

An image forming apparatus comprising:

• an image forming part that forms a designated image on continuous paper;
• a drive roller that transports the continuous paper to the image forming part by a frictional force;
• a pre-centering mechanism that is disposed upstream of the drive roller with respect to a transport direction and regulates a position of the continuous paper with respect to a direction orthogonal to the transport direction by abutting against an edge of the continuous paper extending lengthwise;
• and
• a tension increasing mechanism, disposed upstream of the pre-centering mechanism with respect to the transport direction, that increases tension on the continuous paper,
• wherein the drive roller transports the continuous paper in a forward direction with respect to the image forming part and a direction opposite to the forward direction, and
• wherein the tension increasing mechanism includes a roller that rotates in the forward direction at a circumferential speed slower than a transport speed of the drive roller when the drive roller transports the continuous paper in the forward direction, and that rotates in the backward direction at a circumferential speed faster than the transport speed of the drive roller when the drive roller transports the continuous paper in the backward direction.

An image forming apparatus comprising:

• an image forming part that forms a designated image on continuous paper;
• a drive roller that transports the continuous paper to the image forming part by a frictional force;
• a pre-centering mechanism that is disposed upstream of the drive roller with respect to a transport direction and regulates a position of the continuous paper with respect to a direction orthogonal to the transport direction by abutting against an edge of the continuous paper extending lengthwise;
• and
• a tension increasing mechanism, disposed upstream of the pre-centering mechanism with respect to the transport direction, that increases tension on the continuous paper,
• wherein the drive roller transports the continuous paper in a forward direction with respect to the image forming part and a direction opposite to the forward direction, and
• wherein the pre-centering mechanism includes:
• a guide part that abuts against an edge of the continuous paper to regulate its position;
• and
• a skew roller, provided at a designated angle with respect to the guide part, that energizes the continuous paper so as to press the continuous paper against the guide part when the continuous paper is transported in the forward direction and the backward direction, the designated angle being set variable.