Web conveying apparatus and web conveying control method

A web conveying apparatus that conveys a web, comprising:

• a transverse position displacement detection unit that detects a transverse position displacement of the web;
• a transverse position correction unit that corrects a transverse position of the web by a guide roller;
• a width detection unit that detects a width size in a left-right direction of the web;
• and
• a control unit programmed to determine a correction amount in a feedback control in accordance with the transverse position displacement detected by the transverse position displacement detection unit,
• wherein the control unit is programmed to respond to the web width size not being below a predetermined threshold and accordingly perform feedback control of the transverse position correction unit to adjust the guide roller by the correction amount to correct a position of the web, and
• wherein the control unit is further programmed to respond to the web width size being below the predetermined threshold and accordingly reduce the determined correction amount in the feedback control, and to perform the feedback control of the transverse position correction unit to adjust the guide roller by the reduced correction amount to correct the position of the web.